ompliance with alifornia ish and amedam, assessed at usgs gage #11118000..... 83 figure 33. boles...

ASSESSING FLOWS FOR FISH

BELOW DAMS

A SYSTEMATIC APPROACH TO EVALUATE

COMPLIANCE WITH CALIFORNIA FISH AND GAME

CODE 5937

THEODORE E. GRANTHAM PETER B. MOYLE CENTER FOR WATERSHED SCIENCES UNIVERSITY OF CALIFORNIA, DAVIS ONE SHIELDS AVENUE DAVIS, CA 95616

OCTOBER 22, 2014

This report was prepared by:

Theodore E. Grantham and Peter B. Moyle Center for Watershed Sciences University of California, Davis One Shields Avenue Davis, CA 95616 Corresponding author: Theodore (Ted) Grantham [email protected]

Copyright ©2014 The Regents of the University of California

All rights reserved

The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or service in the uniformed services (as defined by the Uniformed Services Employment and Reemployment Rights Act of 1994: service in the uniformed services includes membership, application for membership, performance of service, application for service, or obligation for service in the uniformed services) in any of its programs or activities. University policy also prohibits reprisal or retaliation against any person in any of its programs or activities for making a complaint of discrimination or sexual harassment or for using or participating in the investigation or resolution process of any such complaint. University policy is intended to be consistent with the provisions of applicable State and Federal laws.

Please cite this report as:

Grantham, T. E. and P. B. Moyle. 2014. Assessing flows for fish below dams: a systematic approach to evaluate compliance of California’s dams with Fish and Game Code Section 5937. Center for Watershed Sciences Technical Report (CWS-2014-01), University of California, Davis. 106 p.

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TABLE OF CONTENTS

Tables ..................................................................................................................................................... v

Figures .................................................................................................................................................. vi

Acknowledgements ............................................................................................................................... ix

Executive Summary ............................................................................................................................... x

Introduction ........................................................................................................................................... 1

Effects of dams on California’s rivers .................................................................................................. 2

Effects of dams on California’s fish populations ................................................................................. 4

Section 5937 and ‘fish in good condition’ ............................................................................................. 6

Applying Section 5937 to restore flows below dams ........................................................................... 8

A systematic approach for evaluating dams ..................................................................................... 10

Methods ................................................................................................................................................ 13

Step 1. Building a dam database ....................................................................................................... 13

Step 2. Assessing flow regime alteration below dams ...................................................................... 15

Step 3. Assessing condition of native fish below dams ..................................................................... 16

Step 4. Identifying regulatory considerations ................................................................................... 18

Step 5. Identifying and ranking candidate dams .............................................................................. 18

Step 6. Preliminary case study investigations .................................................................................. 20

Evaluation Results ............................................................................................................................... 21

Flow regime alteration below dams ................................................................................................... 22

Indicators of fish condition ................................................................................................................. 30

Relationships between hydrologic alteration and fish condition ..................................................... 33

Dams subject to federal environmental flow requirements ............................................................. 36

Identification and ranking of candidate dams .................................................................................. 37

Preliminary site investigations .......................................................................................................... 44

Discussion ............................................................................................................................................ 48

Systematic evaluation of dams ........................................................................................................... 48

Limitations .......................................................................................................................................... 49

Recommendations ............................................................................................................................... 50

Case Studies ......................................................................................................................................... 52

Case study 1: Black Butte Dam ......................................................................................................... 53

Hydrologic Conditions .................................................................................................................. 55

iii

Condition of Downstream Fish Populations ............................................................................... 56

Management of Downstream Flows for Fish .............................................................................. 57

Case study 2: Conn Creek Dam.......................................................................................................... 58




Case study 3: Peters Dam ................................................................................................................... 62




Case study 4: Woodbridge Diversion Dam ........................................................................................ 67




Case study 5. Twitchell Dam .............................................................................................................. 73




Case study 6. Long Valley Dam ......................................................................................................... 77




Case study 7. Casitas Dam ................................................................................................................. 81




Case study 8. Boles Meadow Dam ..................................................................................................... 85




Case study 9. Pine Flat Dam .............................................................................................................. 89



iv


Case study 10. Dwinnell Dam ............................................................................................................ 93




Case study findings ............................................................................................................................. 97

References ............................................................................................................................................ 99

Appendix A ......................................................................................................................................... 107

Sensitive native fish species list ...................................................................................................... 107

Appendix B ......................................................................................................................................... 110

List of dams evaluated ...................................................................................................................... 110

Appendix C ......................................................................................................................................... 129

Model performance evaluation ......................................................................................................... 129

Appendix D......................................................................................................................................... 136

List of candidate dams ...................................................................................................................... 136

v

TABLES

Table 1. Top 20-ranking dams sorted by storage capacity and seasonal flow deviation ...................... 40

Table 2. Top 20-ranking dams sorted by native species richness and sensitive species

richness ................................................................................................................................... 42

Table 3. Top 20-ranking dams sorted by ESA-listed salmon and steelhead trout populations ........... 44

Table 4. Case study dams .......................................................................................................................... 46

Table 5. Black Butte Dam on Stony Creek, Tehama County ................................................................. 56

Table 6. Conn Creek Dam on Conn Creek, Napa County ....................................................................... 61

Table 7. Peters Dam on Lagunitas Creek, Marin County ...................................................................... 64

Table 8. Woodbridge Diversion Dam on the Mokelumne River, San Joaquin County ......................... 70

Table 9. Twitchell Dam on the Cuyama River, San Luis Obispo and Santa Barbara counties ........... 75

Table 10. Long Valley Dam on the Owens River, Mono County ............................................................ 79

Table 11. Casitas Dam on Coyote Creek, Ventura County ..................................................................... 83

Table 12. Boles Creek Dam on Boles Creek, Modoc County. .................................................................. 87

Table 13. Pine Flat Dam on the Kings River, Fresno County. ............................................................... 91

Table 14. Dwinnell Dam on the Shasta River, Siskiyou County. ........................................................... 94

vi

FIGURES

Figure 1. Dams in California ...................................................................................................................... 1

Figure 2. Pre-dam and post-dam mean monthly flows for the American River at Fair Oaks

(USGS gage #1144650) ............................................................................................................ 3

Figure 3. Conceptual diagram of dam evaluation approach ................................................................... 11

Figure 4. Evaluation approach and criteria for identifying dams where improved downstream

flows may be warranted for Section 5937 compliance ......................................................... 14

Figure 5. Dams evaluated in California (n =753) with frequency distributions of dam height,

storage capacity, and upstream catchment areas ................................................................ 21

Figure 6. Histograms of observed/expected mean monthly flows for all gaged dams. O/E

values between 0.75-1.25 (gray bars) indicate that observed flows are similar to

expected values ...................................................................................................................... 23

Figure 7. Histogram of observed/expected maximum 1-day discharge. O/E values near 1 (gray

bar) indicate that observed flows are similar to expected values ....................................... 24

Figure 8. Histogram of correlation coefficient between observed and expected monthly

flows, for all gages below dams. Gray bar denotes high correlation, or strong

correspondence, between observed and expected seasonal monthly flow patterns ........... 25

Figure 9. Examples of seasonal flow alteration below dams, as measured by correlation

between expected (modeled unimpaired) and observed mean monthly flows.................... 26

Figure 10. Impounded runoff (IR) ratio for dams in California, representing the capacity

relative to the (modeled) mean annual inflow; inset map illustrates the

difference between IR and CIR for series of dams on the Pit River ................................... 27

Figure 11. Relationship between O/E monthly flows, O/E maximum 1-day flows, Pearson’s r

and the cumulative impounded runoff (CIR) ratio at gaged dams ..................................... 29

Figure 12. Patterns of species loss from HUC12 watersheds for 28 native fish species with

historical and current range data ......................................................................................... 30

Figure 13. Patterns of sensitive species richness within California’s HUC12 watersheds;

population status of each native species based on Moyle et al. 2011 ................................. 31

Figure 14. Current distribution of anadromous salmonid species, listed as threatened or

endangered under the federal Endangered Species Act .................................................... 332

Figure 15. Native species richness plotted against annual discharge and cumulative storage ........... 33

Figure 16. Number of sensitive species plus species losses, plotted against annual discharge

and cumulative storage capacity ........................................................................................... 34

vii

Figure 17. Number of sensitive species plus species losses, plotted against impounded runoff

(IR), cumulative impounded runoff, monthly flow deviation, maximum 1-day flow

deviation, and seasonal flow deviation; flow deviation metrics are transformed:

increasing values (from 0) indicate increasing degree of deviation from modeled

unimpaired conditions ........................................................................................................... 35

Figure 18. Dams with (gray, n = 165) and without (black, n = 588) known federal

environmental flow requirements ......................................................................................... 36

Figure 19. High priority candidate dams (n = 220) for assessing compliance with Section

5937 ......................................................................................................................................... 37

Figure 20. Ten case study dams from the list of candidate dams (n = 220), selected to provide

preliminary site investigation of the potential effects of dam operations on

downstream fish ..................................................................................................................... 46

Figure 21. Black Butte Dam and catchment (1,916 km2) on Stony Creek. Downstream flows

were evaluated at USGS gage #11388000 below the dam .................................................. 53

Figure 22. Expected (E, modeled) and observed (O) mean monthly flows below Black Butte

Dam and the O/E ratio ........................................................................................................... 56

Figure 23. Conn Creek Dam and catchment on Conn Creek, a tributary to Napa Creek in

Sonoma County. Downstream flows were evaluated at USGS gage #11456500 ............... 58

Figure 24. Peters Dam and upstream catchment (267 km2) on Lagunitas Creek in Marin

County. Downstream Flows were evaluated at USGS gage #11460400 ............................ 62

Figure 25. Expected (E, modeled) and observed monthly flow below Peters Dam on Lagunitas

Creek ....................................................................................................................................... 64

Figure 26. Woodbridge Diversion Dam and catchment (1,682 km2) on the Mokelumne River,

San Joaquin County; inset map shows large upstream dams and USGS gages

above the dams (#11319500), below Camanche Dam (#11323500), and below

Woodbridge Dam (#11325500) .............................................................................................. 67

Figure 27. Observed daily discharge in the Mokelumne River for the 2010 water year, above

Pardee Dam, downstream of Camanche Dam, and below Woodbridge Dam ..................... 71

Figure 28. Expected (E, modeled) and observed mean monthly flow below Woodbridge Dam

on the Mokelumne River ....................................................................................................... 72

Figure 29. Twitchell Dam and catchment (2,888 km2) on the Cuyama River, in southern San

Luis Obispo and northern Santa Barbara counties ............................................................. 73

Figure 30. Long Valley Dam and catchment (994 km2) on the Owen River, Mono County ................. 77

Figure 31. Casitas Dam and catchment (105 km2) on Coyote Creek, a tributary to the

Ventura River, Ventura County ............................................................................................ 81

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Figure 32. Mean monthly flows on Coyote Creek before and after construction of Casitas

Dam, assessed at USGS gage #11118000 ............................................................................. 83

Figure 33. Boles Meadow dam and catchment (692 km2) on Boles Creek, Modoc County ................... 85

Figure 34. Pine Flat Dam and catchment (4,000 km2) on the Kings River in Fresno County.

Flows were evaluated at USGS gage #11221500 ................................................................ 90

Figure 35. Expected (E, modeled) and observed mean monthly flows below Pine Flat Dam on

the Kings River....................................................................................................................... 91

Figure 36. Dwinnell Dam and catchment (142 km2) on the Shasta River, Siskiyou County ............... 93

ix

ACKNOWLEDGEMENTS

Many people have contributed to this report. The development of the evaluation approach

benefited greatly from conversations with Curtis Knight, Monty Schmitt, Brian Johnson,

and Rene Henery, who offered a broad range of expertise pertaining to the management of

dams and their impacts to California’s river ecosystems. We received excellent support from

researchers at the University of California – Davis Center for Watershed Sciences. In

particular, Josh Viers, Nick Santos, and Jacob Katz were instrumental in the development

and analysis of the PISCES database. Eric Holmes and Sarah Yarnell also provided helpful

feedback and research support. Sydney Vickery assisted with figure development and Chris

Bowman provided valuable editorial advice. We thank Daren Carlisle and David Wolock for

technical guidance on hydrologic modeling. Additional helpful discussion and assistance

with data sources came from Marshall Olin, Chandra Ferrari, Joe Merz, Jonathan Koehler,

Steve Parmenter, Dale Mitchell, Greg Andrew, Stuart Reid, Darren Mierau, Mark Drew,

Gordon Becker, Matt Kondolf, Larry Brown and Jeff Thompson. This research was

supported with funding from the Natural Resources Defense Council, California Trout and

Trout Unlimited. We alone are responsible for the analysis, results and recommendations of

this report and any errors herein.

x

EXECUTIVE SUMMARY

There are thousands of dams in California, most of which were built and are operated for

water supply and flood protection benefits with little consideration for their effects on fish.

For more than 100 years, however, the State of California has legally recognized the need to

ensure that adequate flows are released below dams to maintain fish in good condition. In

the early 20th century, Fish and Game Code 5937 was adopted, which states that the

“owner of any dam shall allow sufficient water at all times…to pass over, around, or

through the dam, to keep in good condition any fish that may be planted or exist below the

dam.” Despite the clear language and intent of Section 5937 to protect fish below dams,

dam owners have generally not met this requirement and the state agencies charged with

its implementation have not enforced it. However, successful lawsuits since the 1970s have

applied Section 5937 on several regulated rivers to improve flows for fish and wildlife, and

indicate that there is an opportunity for broader implementation of environmental flows in

California’s rivers and streams.

Sections 5937’s legal requirement to ensure adequate flows for fish potentially applies to

thousands of dams in California. However, determining which dams may not be in

compliance with the code is a daunting task that state agencies have not undertaken to

date. There remains a need for a systematic assessment of dams to ensure uniform and

balanced implementation of Section 5937 flow protections throughout California. Such flow

protections are critical to the preservation of California’s native fish species and fishery

resources, which are severely threatened by river ecosystem degradation, human

population growth and climate change.

This technical report presents an evaluation approach to identify dams in California where

flow modifications and/or other management actions may be warranted to comply with

Section 5937. The approach follows a tiered framework that focuses on the inventory,

characterization, and selection of dams based on evidence of flow regime alteration and

downstream fish community impairment. First, a database of dams is compiled and used to

define the distribution and characteristics of California dams. Next, hydrologic conditions

below dams are assessed to quantify the extent to which flows may deviate from natural,

unimpaired conditions. The condition of native fish in proximity to each dam is then

evaluated based on range maps and population status. Indicators of fish condition

impairment were assessed in the sub-watersheds within which dams were located and

included (1) the loss of native fish species based on their historic range and (2) the presence

of native fish species considered at risk of extinction. All dams associated with evidence of

hydrologic alteration and indicators of fish condition impairment were then identified and

ranked. Finally, a series of case studies were selected from the list of dams potentially in

need of improved environmental flows to provide diverse, site-specific examples of how dam

operations may be affecting the condition of downstream fish.

xi

Following an initial evaluation of more than 1,400 large dams in California, this analysis

focused on 753 dams that are likely subject to Section 5937 flow requirements. These dams

occur within a broad range of biogeographic settings and represent a diversity of sizes and

operational purposes. They are distributed throughout the state, but occur in highest

density in the Sierra Nevada, central and south Coast Ranges, and the upper Klamath

River Basin. There are relatively few qualifying dams in the north coast region of

California, which has a dense network of rivers, and in the southeastern region of the state

where few rivers are present.

There is evidence that many of the dams evaluated have potential to alter downstream flow

regimes. About 350 dams have storage capacities large enough to capture more than 50% of

annual river inflow. Reservoir storage capacity was equal or greater than total annual

inflow for 178 dams. For dams with downstream flow gages (about 200), there was evidence

of substantial flow regime alteration. For the vast majority of gaged dams, observed flows

deviated from expected natural patterns by at least 50% for at least six months of the year.

In addition, for more than half of the gaged dams evaluated, maximum 1-day flows were

less than 50% of predicted values. Although several dams appear to have substantially

altered seasonal flow patterns (assessed by correlation between observed and expected

monthly flows), flow seasonality has been largely preserved below most gaged dams.

About 400 of the 753 dams evaluated are within the range of at least one sensitive fish

species (i.e., those with vulnerable or threatened population status), including more than

200 within the range of anadromous salmonids listed under the federal Endangered Species

Act. There are an additional 250 dams located in watersheds that have lost at least one

native species based on their historic ranges. A comprehensive, statistical analysis of the

relationships between dam-related flow alteration and fish condition was beyond the scope

of this study. There was, however, some evidence that the number of sensitive species and

species losses is associated with hydrologic alteration below dams. For example, dams with

no sensitive species or losses were generally associated with the lowest degree of hydrologic

alteration, based on impounded runoff, cumulative impounded runoff, and maximum 1-day

flow deviation metrics. The association of dams with indicators of biological impairment is

not causal evidence that dam operations are responsible for the poor condition of fish.

However, a large body of literature documenting the impacts of dams on fish assemblages

strongly suggests that dam operations remain an important threat to the persistence of

California’s native fish populations.

From an initial list of more than 1,400 dams, 220 were identified as high-priority sites to

further assess the condition of fish based on evidence of hydrologic and biological

impairment. These dams were then ranked and sorted based on their physical features

(reservoir capacity), hydrologic indicators (degree of seasonal flow alteration), and

associated fish community characteristics. High-priority dams with the largest water

storage capacities include many of the state’s biggest dams: Trinity Dam on the Trinity

River, New Melones Dam on the Stanislaus River, Pine Flat on Kings River, and Folsom

xii

Dam on the American River. Dams associated with the greatest downstream hydrologic

alteration were also identified and ranked. Among the subset of dams with downstream

U.S. Geological Survey (USGS) gaging stations, Tinemaha Dam on the Owens River, and

Anderson Dam on Coyote Creek, and Calaveras Dam on Calaveras Creek were associated

with the greatest alteration to seasonal monthly flow patterns. High-priority dams

associated with the greatest richness of native species include Woodbridge Diversion Dam

on the Mokelumne River, Nash Dam on a tributary to Stillwater Creek in Shasta County,

and a series of three Rubber Dams on lower Alameda Creek. The dams associated with the

greatest number of native species with sensitive population status included Keswick and

Anderson-Cottonwood dams, Woodbridge Diversion Dam, and Nash Dam.

Ten case studies were selected from the list of high-priority candidate dams to provide

specific examples of how dam operations may be affecting the downstream fish community.

The case study dams were selected to illustrate the diversity of dam types throughout the

state, and do not necessarily represent those in greatest need of improved flows for fish.

The case study investigations found that indicators of hydrologic alteration and fish

population impairment assessed in the systematic evaluation generally corresponded with

documented, site-specific environmental effects of dams. In addition, observed downstream

flow alteration was generally coupled with significant downstream habitat alteration.

Therefore, poor habitat conditions below many dams suggest that improving flows for fish

may also require habitat restoration to maintain fish in good condition. Overall, the case

studies illustrated that each dam has a unique set of management constraints,

jurisdictional issues, and environmental factors that must be addressed in the context of

Section 5937. This is probably true of all dams, and we recommend that site-specific

analyses presented in the case studies be done for every high-priority dam identified in this

investigation.

This investigation revealed inaccurate data a general lack of information on dam

operations, downstream flow regimes, and affected fish communities. The vast majority of

dams currently have no downstream flow monitoring stations. The state’s inaccurate

reporting and tracking of water availability and use (i.e., diversions) significantly impedes

management of environmental flows in California’s rivers. In addition, the sporadic

availability and quality of fish observations greatly hinders a statewide assessment of the

ecological impacts of dams. For this investigation, we used a new geospatial database of

California fish distributions to identify fish species associated with dams at the HUC12-

watershed scale. However, the spatial association of fish species downstream of specific

dams (upon which the selection criteria are based) is not conclusive. We recommend that

indicators of fish community impairment (e.g. sensitive species or loss of species from

historic range) below dams be confirmed as part of site-specific investigations.

The effects of California dams in downstream flows remains poorly documented. Therefore,

this evaluation approach can be improved as new data and modeling tools become

available. Additional monitoring data on downstream flows and fish communities could

xiii

change the rankings of dams on the high-priority list. New criteria could also be

incorporated in the evaluation framework to support the selection and ranking of high-

priority dams for further assessment. Information on the relative vulnerability of

California’s fish assemblages to climate change is particularly needed for informing

environmental flow implementation strategies. The data-driven framework for evaluating

dams is a flexible and adaptive way to incorporate new sources of information to guide river

management and decision-making.

This investigation represents the first attempt to systematically evaluate the impacts of

California’s major dams on native fish species in the context of Section 5937. The study

presents evidence indicating that many California dams are not in compliance with Section

5937. Given the rapid decline of California’s fish fauna and pervasive alteration of the

state’s river ecosystems, environmental flow protections are critical for conservation of

many native fish populations and are likely to become increasingly so in the future. There

is an urgent need for the State to develop an approach to evaluate the compliance of

existing dams with its laws to protect California’s fish. This initial screening approach

identifies dams that likely warrant site-specific studies and offers guidance on

implementing environmental flows to comply with Section 5937.

Keywords: environmental flows, water management, regulated rivers, freshwater fishes,

biodiversity conservation, dams, Fish and Game Code Section 5937, California

INTRODUCTION | 1

INTRODUCTION

California has thousands of dams, from small earthen barriers

that create ponds for local use to megastructures hundreds of

feet tall impounding the state’s major water-supply sources.

Building dams on California’s free-flowing streams and rivers

began in the 1850s, accelerated during the 19th century in

response to demands of hydraulic mining and logging, and

peaked between 1900 and 1920 with the expansion of irrigated

agriculture. Construction of the State’s largest water-supply

dams, mostly by the federal government, was concentrated

between 1940 and 1970. Today there are more than 1,400 dams

that are large enough to fall under state regulations for safety

(DWR 2010). In addition, more than 1,700 smaller dams have

been inventoried on California’s rivers and streams (CDFW

2012). These dams a on essentially every major river and

stream in the state (Figure 1) and collectively impound over 42

million acre feet, equivalent to 60% of the average runoff in

California (Mount 1995).

Figure 1

Dams in California

2 | RESTORING FLOWS FOR FISH BELOW DAMS

EFFECTS OF DAMS ON CALIFORNIA’S

RIVERS

All dams alter the timing and magnitude of river flows.

California’s mediterranean climate is characterized by a

distinct wet season, associated with brief, intense storms

followed by a prolonged period of seasonal drought. This

seasonal pattern of water availability is out-of-phase with

human water demands, which increase during the dry season

primarily to support irrigated agriculture. California’s climate

seasonality thus has been a strong catalyst for reservoir

construction (Gasith and Resh 1999). In addition, multi-year

droughts are common in California, as are extreme flood events

(Cayan et al. 1999), prompting the need for large reservoirs to

enhance water-supply reliability and provide flood protection.

As a result, one of the most common effects of dams on river

flows in California is reduction in magnitude and frequency of

high-flow events (Kondolf and Batalla 2005). Stream flows

below dams are often augmented in the summer through late

fall to support irrigated agriculture and to expand flood

retention capacity of reservoirs (Grantham et al. 2012; Singer

2007). “Flattening” of the seasonal flow regime, resulting from

decreased high flows and increased base flows, has been

observed in the Sacramento River and all its major tributaries

(Brown and Bauer 2010), such as the American River (Figure

2).

INTRODUCTION | 3

Figure 2

Pre-dam and post-dam mean monthly flows for the American

River at Fair Oaks (USGS gage #1144650)

Flow alteration by dams often leads to downstream changes in

channel morphology. As a result of reduced peak flows, width of

the high-flow channel tends to decrease and the area of

regularly inundated floodplain is reduced (Graf 2006). With the

loss of flows that scour the streambed, vegetation can establish

in the active channel, resulting in the loss of channel

complexity and instream habitat structure (Magdaleno and

Fernández 2011). Dams also impact sediment transport

processes. Large dams completely block bedload transport and

reduce suspended sediment transport by inducing deposition in

the low-velocity waters of reservoirs. Since the construction of

major dams in the Sacramento–San Joaquin basin, annual

bedload transport has fallen by an average of 45%, with total

bedload of particles greater than 8 mm decreasing by 42%

(Minear 2010). When reaches below dams are deprived of their

sediment load, a condition known as “hungry water” can occur,

whereby flows still have the energy to move sediment but have

lost their supply, resulting in downstream erosion and bed

incision (Kondolf 1997). Exceptions occur when flows have been

reduced to the point that they can no longer carry sediments

from downstream tributaries, resulting in aggradation (Kondolf

et al. 2012).


Finally, an obvious, but perhaps underappreciated effect of

dams is the creation of artificial reservoirs, which have

considerably different physical and ecological properties than

free-flowing rivers. The conversion of lotic (flowing water) to

lentic (standing water) freshwater ecosystems alters the flux of

nutrients and organic matter through river networks, increases

surface water losses through evaporation, and creates novel

habitats to which native biota may be poorly adapted. In

regions that naturally have few perennial freshwater lakes,

such as California’s coast ranges, the creation of artificial

reservoirs by dams represents a significant transformation of

river ecosystem structure and functions.

EFFECTS OF DAMS ON CALIFORNIA’S FISH

POPULATIONS

California’s native freshwater fish species are experiencing

widespread and rapid decline. A recent assessment of

California’s freshwater fish populations indicates that 76% of

the state’s native fish species are vulnerable to extinction if

present trends continue (Moyle et al. 2011). Predicted effects of

climate change are likely to accelerate this declining trend

(Moyle et al. 2012). While many factors have contributed to the

imperilment of California’s native fish species, the alteration of

river ecosystems by dams is recognized to be a dominant driver

of population declines (Moyle 2002; Katz et al. 2012; Moyle et

al. 2011).

Dams have particularly impacted California’s anadromous fish

populations, including commercially and culturally significant

salmon and steelhead trout (Katz et al. 2012), but also several

species of lamprey and sturgeon (Moyle 2002). Dams create

barriers along river corridors that restrict or completely block

access to upstream habitat of migratory species. For example,

construction of impassable dams in the Sacramento River basin

has reduced availability of habitat historically used by salmon

and steelhead by more than 70% (Yoshiyama et al. 2001;

Lindley et al. 2006). Migratory fish species also encounter

many small dams, diversions, and culverts that obstruct

movement; more than 17,000 potential barriers to fish passage

have been documented in California’s river and streams

INTRODUCTION | 5

(CDFW 2012). The loss of habitat connectivity within river

networks has significant implications for the persistence of

anadromous fishes and other cold-water species, because

warming water temperatures from climate change is expected

to reduce the suitability of remaining accessible habitats below

dams (Katz et al. 2012; Moyle et al. 2012).

The alteration of flows below dams is generally considered to be

the most serious threat to ecological sustainability of rivers

(Bunn and Arthington 2002; Nilsson et al. 2005; Dudgeon et al.

2006). Fish and other aquatic organisms are highly adapted to

the natural seasonal flow variability that characterizes river

ecosystems (Lytle and Poff 2004). For example, adult Pacific

salmon typically enter California’s rivers to begin their

migration to spawning grounds following the first major storms

of the year, when elevated flows facilitate upstream passage

(Moyle 2002). Spawning often occurs in the early spring, when

flows are still elevated by the risk of egg mortality by bed-

scouring flows is low (Montgomery et al. 1999). Out-migrating

juvenile salmonids take advantage of seasonally inundated

floodplains in the spring for rearing, which improves their

growth and survival (Opperman et al. 2010). Other native

species such as the Sacramento splittail (Pogonichthys

macrolepidotus) are also dependent on the inundation of

floodplain habitats in the early spring for spawning (Moyle

2002). Therefore, when seasonal patterns in the timing and

magnitude of flows (including floodplain inundation flows) are

altered by dams, many species are unable to successfully

complete their life cycles.

Dams also cause downstream incision and reduction in channel

complexity (Graf 2006), deteriorating the quality and

availability of habitat for fish and other aquatic biota. The

disruption of sediment transport can lead to the coarsening of

channel bed materials and loss of spawning habitat for salmon,

trout, and other species. In several of California’s regulated

rivers, gravel is regularly imported and deposited below dams

to maintain spawning habitat for threatened salmon

populations (Pasternack et al. 2004).


Finally, dams impair native fishes by facilitating establishment

of non-native species (Bunn and Arthington 2002). Reservoirs

provide slow-water habitat favorable to non-native fishes such

as common carp (Cyprinus carpio), largemouth bass

(Micropterus salmoides), sunfishes (Lepomis spp.), and

mosquito fishes (Gambusia spp.), which often outcompete or

prey upon resident natives. The stabilization of river flows

downstream of dams also promotes non-natives species, for

example, by reducing the frequency and intensity of flood

disturbance that would otherwise suppress their populations

(Marchetti and Moyle 2001).

SECTION 5937 AND ‘FISH IN GOOD

CONDITION’

The potential for dams to harm fish and fisheries has long been

recognized in California. As early as 1852, less than two years

after California entered the Union, the state Legislature

outlawed the placement of instream obstructions to salmon

migrations (Börk et al. 2012). Subsequent laws enacted in 1870

and 1880 further protected migratory fish. Nevertheless,

repeated reports of drying rivers indicated that many dam

operators ignored early fish passage laws (Börk et al. 2012). A

1914 Fish and Game Commission study that documented

impacts of low water flows on fish prompted the Legislature to

enact the 1915 Flow Act, which explicitly required flow releases

below dams to protect fish. This law eventually became Section

5937 of the state Fish and Game Code, which states:

“The owner of any dam shall allow sufficient water at all

times to pass through a fishway, or in the absence of a

fishway, allow sufficient water to pass over, around, or

through the dam, to keep in good condition any fish that

may be planted or exist below the dam.”

The language plainly indicates that the dam owners have the

responsibility to release enough water to support fish. But

what does it mean to maintain “fish in good condition” and

what flows below dams are required to do so?

INTRODUCTION | 7

“Good condition” is not explained in the code, but has been

defined through a series of court decisions in the 1990s (Moyle

et al. 1998). In essence, fish downstream of dams are

considered to be in good condition when the species present are

comprised of healthy individuals with self-sustaining

populations and represent an assemblage that is dominated by

native species and is persistent over time (Box 1). In the

context of Section 5937, maintaining fish in good condition

requires a flow regime that allows for downstream fish to

complete their life history cycles, reproduce successfully in

most years, and maintain a species assemblage that is resilient

to disturbance.

Box 1

Table 1

Dr. Peter Moyle has provided an interpretation of “fish in good condition” that has been

used in legal decisions concerning Section 5937 (Moyle et al. 1998). The condition of

fish is assessed at the individual, population, and community level.”

Health at the individual level means that fish have a (1) robust body composition; (2)

are relatively free of disease, parasites, and lesions; (3) should have reasonable growth

rates for the region; and (4) respond in an appropriate manner to stimuli. This can be

generally assessed by examining the condition and growth rates of individual fish.

At the population level, good condition means that populations of individual species (1)

contain multiple age classes (evidence of reproduction); (2) a viable population size; and

(3) healthy individuals (as above).

At the community level, good condition is defined as a fish assemblage that is (1)

dominated by native, co-evolved species; (2) has a predictable structure as indicated by

niche overlap among the species and multiple trophics levels; (3) is resilient to

recovering from extreme events; (4) is persistent in species membership through time;

and (5) is replicated geographically.


APPLYING SECTION 5937 TO RESTORE

FLOWS BELOW DAMS

Despite the clear language and intent of Section 5937 to protect

fish below dams, dam owners have generally not met this

requirement and the state agencies charged with its

implementation have not enforced it (Börk et al. 2012).

However, recent lawsuits have re-affirmed the need to provide

adequate flows for fish under Section 5937 (Börk et al. 2012),

and illustrate how the code could be applied to other river

systems. Putah Creek offers a notable example of the

successful application of Section 5937 in California (Box 2).

However, Section 5937 has also played an important role in

restoring flows to streams that drain into Mono Lake

(California Trout, Inc. v. State Water Resources Control Board

and California Trout, Inc. v. Superior Court) and in increasing

water releases for fish below Friant Dam in the San Joaquin

River (NRDC v. Patterson).

While these cases provide useful illustrations of the application

of Section 5937, specific flows requirements to maintain fish in

good condition are highly context-dependent. For example,

large regulated rivers that support salmon and other

anadromous species below dams will have substantially

different flow needs than streams in upper watersheds that

support resident native species. Under Section 5937, all

waterways below dams that would naturally have perennial

flows should have sustained minimum flows needed to support

a “living stream” (Moyle et al. 1998). However, the magnitude

and timing of flow releases needed to support fish will require

consideration of the natural flow regime and ecological

requirements of the species present (or potentially present

under restored conditions) within the river of interest.

INTRODUCTION | 9

Box 2

The requirements of Section 5937 are also not static in time. In

calling for downstream flows that keep fish in good condition

“at all times”, the code allows for flow requirements to be

adapted to changing circumstances in the future. This is

particularly relevant with respect to climate change, which is

expected to cause warmer water temperatures, altered flow

patterns, and water quality degradation, all threats to

California’s freshwater fish (Moyle et al. 2012). Therefore, the

successful application of Section 5937 requires an adaptive

approach, whereby flow requirements may be modified in

response to changes in the local environment and fish

community conditions, as determined by biological monitoring.

In the 1950s, the U.S. Bureau of Reclamation built Monticello Dam on Putah Creek, a

tributary to the Sacramento River in Yolo County. Stream flow in lower Putah Creek is

completely regulated, except when large storms cause the dam to spillover. During a late

1980s drought, releases were so meager that a 30-km section of lower Putah Creek dried,

resulting in fish kills and harm to riparian wildlife. In response, a citizen’s group, UC

Davis and the City of Davis sued to increase flows (Putah Creek Council v. Solano

Irrigation District and Solano County Water Agency). The trial court, citing Section 5937,

ordered a 50% increase in the minimum release schedule to keep the creek flowing to its

mouth. Subsequent negotiations led to the Putah Creek Accord (Accord), signed in May

2000, which established additional operational requirements to benefit fish and other

aquatic organisms (Moyle et al. 1998).

The Accord’s flow recommendations were based on the ecological needs of species and

assemblages in the creek and were derived from the three-tiered definition of fish in good

condition (Box 1, Moyle et al. 1998). The recommendations included increased spawning

and rearing flows for native fish; pulse flows to attract and support anadromous fish;

minimum flows to sustain fish in droughts.

Nine years of creek monitoring indicates that the new flow regime has been successful in

promoting the expansion and health of native-dominated fish assemblages throughout

the creek (Kiernan et al. 2012). Importantly, the restoration of native fishes was achieved

by manipulating stream flows at biologically important times of the year and only

required a small increase in the total volume of water delivered downstream (i.e., water

that was not diverted most years).


Sections 5937’s legal requirement to ensure adequate flows for

fish potentially applies to thousands of dams in California.

However, determining which dams may not be in compliance

with the code is a daunting task that state agencies have not

undertaken to date. The number of dams and unique biological,

hydrological and geographic characteristics of each affected

river suggest that a systematic approach is needed to identify

dams where improved downstream flows may be required.

Although site-specific studies will be necessary to ultimately

determine the need for Section 5937 flows, an initial screening

of dams based on indicators of hydrologic alteration and fish

community condition, will help to prioritize sites for Section

5937 compliance.

A SYSTEMATIC APPROACH FOR

EVALUATING DAMS

The primary goal of this study was to develop an approach to

identify and evaluate California dams that have impaired

downstream fish communities associated with altered flow

regimes. The evaluation follows a systematic, six-step process

that focuses on the inventory, characterization, and selection of

dams where environmental flows may be warranted under

Section 5937 (Figure 3). First, a database of dams is compiled

and used to define their distribution and characteristics. Next,

hydrologic conditions below dams are assessed to quantify the

extent to which flows may deviate from natural, unimpaired

conditions. Third, condition of native fish near each dam is

evaluated. The fourth step is the identification of regulatory

considerations that could affect implementation of

environmental flows below specific dams. In the fifth step,

dams with evidence of hydrologic alteration and indicators of

fish community impairment are identified and ranked. For the

sixth and final step, we select a subset of dams for initial

assessment of their potential effects on native fish downstream.

The assessments are a diverse series of case studies from

different regions of California.

INTRODUCTION | 11

Figure 3

Conceptual diagram of dam evaluation approach

This investigation is a first attempt at developing a

comprehensive, data-driven approach for evaluating

California’s major dams and their impacts on native fish

species in the context of Section 5937 requirements. The

evaluation identifies dams where altered downstream flow

regimes may be harming native fish. Deficiencies in the quality

and resolution of data on dam operations and their effects on

downstream fish make it impossible to conclusively assess

Section 5937 compliance. The evaluation, nevertheless,

provides clear indication of which dams are associated with

evidence of biological and hydrological alteration and can be

immediately used for setting priorities for further research,

including site-specific studies on the effects of dam operations

on fish.


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METHODS | 13

METHODS

STEP 1. BUILDING A DAM DATABASE

We developed a database of California dams from three datasets: the

Army Corps of Engineers’ (USACE) National Inventory of Dams

(USACE 2010), the Jurisdictional Dams from the California

Department of Water Resources (DWR 2010), and the National

Marine Fisheries Service’s (NMFS) Dam Dataset for Assessing

Anadromous Fish Passage (Goslin 2005). The USACE and DWR

datasets are comprised of dams at least 1.8-m (6-ft) high with a

storage capacity greater than 60,000 m3 (50 acre feet), or that are

more than 7.6-m (25-ft) high and store at least 18,500 m3 (15 acre

feet).

The NMFS dataset was synthesized from earlier versions of the

USACE and DWR datasets, but includes quality-controlled

geographic location of dams in a GIS, based on the 1:100,000

National Hydrography Dataset (NHD) (Horizon Systems 2012). The

NMFS dataset was used as the foundation of the database, which

was updated with unique records and attributes from the more

recent USACE and DWR datasets. New dam records added to the

database were mapped in a GIS by their latitudinal and longitudinal

coordinates, and, where necessary, manually relocated to the correct

position based on the NHD streamline layer and ortho-rectified

aerial photos.

We then filtered the database for dams with potential to be managed

for environmental flows (Figure 4). First, we excluded dams not

directly located on a stream channel, based on the NHD 1:100,000-

scale streamlines. This included hydropower facilities (e.g., forebays)

that do not drain directly into streams and projects located in

urbanized catchments, such as wastewater treatment facilities,

percolation basins, and urban ponds. Debris basins, retention ponds,

and other passive impoundments were also excluded. For dams

comprised of multiple project works (e.g., those with multiple dikes

and spillways), we included only the primary impoundment

structure. Finally, dams with drainage areas less than 1 km2 (0.4

mi2) and with storage capacities less than 100,000 m3 (80 acre feet)

were excluded. While these dams are also subject to Section 5937,

we considered them low-priority for this initial assessment based on

their small size and location in upper watersheds.


Figure 4

Evaluation approach and criteria for identifying dams where improved downstream

flows may be warranted for Section 5937 compliance

METHODS | 15

STEP 2. ASSESSING FLOW REGIME

ALTERATION BELOW DAMS

Dams have the potential to alter flow regimes in ways that

significantly affect fish and other aquatic biota, including

changes in the timing and magnitude of flows and disruption of

natural patterns of seasonal flow variability (Bunn and

Arthington 2002; Poff et al. 1997). To assess the degree of

hydrologic alteration below dams in California, we examined

USGS flow gaging records at, or near (within 1 km

downstream) dams. The analysis included only gages with at

least 10 years of daily flow records between 1970 and 2012.

We assessed potential changes in the magnitude and

seasonality of monthly flows and changes in the magnitude of

maximum 1-day flows below gaged dams (Figure 4).

Predictions of expected, unimpaired monthly and maximum 1-

day flows were generated using a statistical modeling approach

developed by USGS (Carlisle et al. 2010a; Carlisle et al. 2010b).

The models parameterize relationships between geospatial

attributes (e.g., climate, topography, soils) and hydrologic

responses at reference gages (i.e., those with no upstream dams

and limited land use disturbance) to predict hydrologic

conditions at dams based on upstream catchment

characteristics. Deviation from expected flow magnitudes was

assessed by the ratio of observed (calculated from daily flow

records) to expected (modeled) values. Alteration to seasonal

flow patterns was also assessed by quantifying the correlation

between observed and expected mean monthly flows (Batalla et

al. 2004; Kondolf and Batalla 2005). Pearson’s correlation

coefficient (r) was calculated, which varies between -1 and 1,

with a value of 1 indicating a positive (increasing) correlation

and -1 indicating a negative correlation. Deviation from

expected seasonal flow patterns is expressed as decreasing

values from 1.

Because of the limited distribution of USGS gage stations,

information on downstream flows was not available for the

majority of dams evaluated in this study. However, the

potential for flow alteration was assessed for all dams by the

impounded runoff (IR) ratio, which is the reservoir storage

capacity divided by the mean annual inflow. The IR reflects the


dam’s capacity to capture a river’s flow and is strongly

correlated with indicators of hydrologic alteration, such as

reductions in peak-flow magnitudes and disruption of seasonal

flow patterns (Batalla et al. 2004; Kondolf and Batalla 2005;

Singer 2007). Mean annual inflow at each dam was calculated

by the statistical modeling approach (described above). The

storage capacity for each dam was derived from values reported

in public dam datasets (USACE 2010; DWR 2010). The

cumulative impounded runoff (CIR) was also calculated to

consider the potential influence of dams from the upper

catchments on a downstream dam. For each dam, the reservoir

storage capacity was added to the storage capacity of all

reservoirs in the upstream catchment area, which was then

divided by the mean annual inflow.

STEP 3. ASSESSING CONDITION OF

NATIVE FISH BELOW DAMS

To assess condition of fish in rivers affected by dams, we used

PISCES (Viers et al. 2012), a GIS database and visualization

system for mapping, modeling and analysis of California native

fish species. PISCES incorporates empirical data and expert

knowledge to estimate historic and current species’ ranges at

the Hydrologic Unit Code 12 (HUC12) watershed scale. Within

California, there are 4,644 HUC12 watersheds, which have an

average area of 91±54 km2 [35±20 mi2 (mean±SD)]. Because of

the spatial scale at which data are compiled in PISCES, data

on fish assemblages are generally not distinguished for river

reaches above and below dams within a HUC12 watershed.

Therefore, the indicators of fish community condition are

associated spatially with dams, but do not necessarily reflect

the causal effects of dam operations on fish.

“Fish in good condition” at the community level is defined by an

assemblage of species that is persistent in time (Box 1).

Therefore, the loss of native species from HUC12-watersheds

affected by dams was selected as a potential indicator that the

fish community is not in good condition. To determine if native

fish species have been lost in watersheds affected by dams, we

compared historic to current range maps and calculated the

change in native species richness for all watersheds. The

METHODS | 17

analysis focused on 28 native species for which reliable historic

and current range information was available. All dams were

identified that have lost native species from the HUC12

watershed within which they occur.

Fish in good condition also applies at the population level. To

assess the condition of native fish populations potentially

affected by dams, current species range maps were integrated

with a recent assessment of population status (Moyle et al.

2011). As part of the assessment, each of California’s 129

native fish species was assigned a conservation status,

indicating whether their population is extinct (0), endangered

(1), vulnerable (2), near-threatened (3), or relatively secure (4).

For this study, we considered all species with a status of 2 or

less to be an indicator that a population may not be in good

condition. We identified all dams within the current range of

these “sensitive species” (n = 66, Appendix A), which could

potentially be affected by the operation of upstream dams.

As a final criterion, we identified dams within the current

range of Pacific salmon listed as threatened and endangered

under the federal Endangered Species Act (ESA). These species

include Central Valley spring- and winter-run and California

coast Chinook salmon (Oncorhynchus tshawytscha), Central

California coast and Southern Oregon/Northern California coho

salmon (O. kitsutch), and several distinct population segments

of steelhead trout (O. mykiss), including Southern California,

Central and South Central California coast, Central Valley,

and Northern California. These populations are all considered

“sensitive” (as defined by the Moyle et al. (2011) population

status of 2 or less) and are evaluated independently because of

their high conservation importance, fishery value, and cultural

significance.

Once the set of criteria describing hydrologic- and fish

conditions was compiled for each dam, we explored the

association among variables. A robust statistical analysis of the

relationships between dam-related flow alteration and fish

condition was beyond the scope of this study. However, a series

of box plots were generated to provide an initial qualitative

assessment of the associations among the hydrologic and

ecological variables.


STEP 4. IDENTIFYING REGULATORY

CONSIDERATIONS

The fourth step in dam evaluation involves identification of

regulatory considerations relevant to Section 5937. Because the

goal of this study is to identify dams that may require

improved downstream flows to support native fish, those with

established regulatory processes to protect environmental flows

were filtered from the analysis. For example, hydropower dams

regulated by the Federal Energy Regulatory Commission

(FERC) are subject to a licensing process that requires

environmental flows to mitigate impacts to downstream biota.

Therefore, implementation of Section 5937 at FERC dams is

considered a lower priority than at dams not subject to FERC

regulations. For this reason, we excluded all FERC-regulated

dams for evaluation. Likewise, we excluded dams subject to a

federal biological opinion requiring environmental flows for

ESA-listed species.

STEP 5. IDENTIFYING AND RANKING

CANDIDATE DAMS

The goal of this step in the evaluation process is to identify a

subset of candidate dams for which evidence of hydrologic

alteration and fish community impairment exists, excluding

those subject to federal environmental flow requirements.

The criteria for hydrologic alteration were based on deviation

from observed flow patterns (magnitude of monthly and

maximum 1-day flows and seasonality) and high values for

impounded runoff and cumulative impounded runoff, which

indicates that the dam has the potential to capture most or all

of the rivers annual inflow at that location. There are no

general, transferable quantitative relationships between flow

alteration and ecological responses that can be used to set

objective thresholds of flow impairment likely to harm fish and

other stream biota (Poff and Zimmerman 2010). However, a

review of environmental flow standards suggested that flow

alteration greater than 20% is likely to cause moderate to

major changes in natural ecosystem structure and functions.

METHODS | 19

(Richter et al. 2011). There is also evidence that the risk of

ecological impairment consistently increases with the

magnitude of hydrologic alteration (Carlisle et al. 2010b; Poff

and Zimmerman 2010).

We considered deviation in monthly and maximum 1-day flows

of 50% as a reasonable threshold criterion, which is likely to

result in ecological impacts and is large enough to limit the

potential effects of model uncertainty on flow alteration (i.e.,

observed/expected flow metrics). The threshold criterion for

deviation in seasonal flow patterns was defined by a Pearson’s

r correlation coefficient of less than 0.5. Values greater than 0.5

indicate that observed and expected monthly flows are highly

correlated, signifying that observed flow seasonality generally

follows expected patterns. Finally, an impounded runoff (IR) or

cumulative runoff (CIR) index greater than 0.75 was used as a

criterion for hydrologic alteration, based on previous studies

that have shown IR values to be a strong indicator of flow

regime impacts (Kondolf and Batalla 2005; Singer 2007; Eng et

al. 2012).

The criteria for selecting dams associated with fish community

impairment included (1) the loss of at least one native fish

species, (2) the presence of species with populations in decline

or at risk of extinction, and (3) the presence of ESA-listed

Pacific salmon. Using the PISCES database, we evaluated

indicators of fish impairment at all HUC12 watersheds

containing dams. Dams within watersheds that have lost at

least one species (based on the comparison of historic versus

current ranges of 28 native fish) were selected, as were dams in

watersheds within the current range of sensitive species [i.e.,

conservation status of 2 or less per Moyle et al. (2011)]. Dams

associated with ESA-listed Pacific salmon were also identified.

The final subset of dams consisted of those satisfying one or

more of the hydrologic criteria and those associated with at

least one indicator of fish impairment. These dams were then

sorted and ranked by dam size (reservoir capacity), impounded

(and cumulative impounded) runoff ratio, and other hydrologic

impact criteria. These sorting criteria emphasize the largest

dams and those with potential for significant hydrologic

impacts. Additional sorting criteria were applied to highlight

dams affecting fish assemblages of potential conservation


significance, and included the number of sensitive species and

total number of native species potentially present in the

affected watershed.

STEP 6. PRELIMINARY CASE STUDY

INVESTIGATIONS

Several case study dams were selected from the final subset

(Step 5). These dams are not necessarily those most in need of

environmental flow management. Rather, they exemplify the

broad geographic distribution of dams in the state and

illustrate the diversity of dam types, size and operations. For

each dam, we describe its basic structural and operational

characteristics, current downstream flow regime, and the

native fish species potentially affected. Where available,

technical reports and other relevant sources were used to

validate and expand upon results of the evaluation.

EVALUATION RESULTS | 21

EVALUATION RESULTS

A total of 1,440 unique California dam records were compiled

from existing datasets (Goslin 2005; USACE 2010; DWR 2010).

From this list, 515 were identified as off-stream dams,

retention basins, or other facilities that do not release water

directly into streams. An additional 172 dams with small

drainage areas [<1 km2 (<0.4 mi2)] and/or low storage

capacities [<100,000 m3 (<80 acre feet)] were excluded. The 753

remaining dams were selected for further assessment

(Appendix B). These dams represent a broad range of sizes,

storage capacities, and drainage areas (Figure 5). The dams

also include those that are privately owned (n = 339) and those

owned and operated by local (n = 279), state (n = 27) and

federal agencies (n = 108).

Figure 5

Dams evaluated in California (n =753) with frequency distributions of dam height,

storage capacity, and upstream catchment areas


FLOW REGIME ALTERATION BELOW DAMS

A total of 209 USGS flow gages were identified at or

immediately downstream of dams. Potential alteration to flow

magnitudes and seasonal flow patterns was first assessed by

comparing modeled mean monthly flows (representing expected

hydrologic conditions in the absence of dams) with observed

flows. Only gages with at least 27 days of daily flow records per

month for 10 years or more were included, resulting in 172

gages below 185 dams. For most gage sites, the ratio of

observed-to-expected (O/E) mean monthly flows was less than

1, indicating that flow releases from dams are, on average,

lower than expected. Monthly O/E values were generally lower

in winter and spring (Nov-May) than in the summer and fall

(Jul-Oct) when values were greater than 1 for some sites

(Figure 6). This probably represents the effects of water storage

and flood control in the winter, and augmented flow releases in

the late summer for agricultural water deliveries. Comparisons

of observed and predicted flows at reference gages indicated

that the model was unbiased and reasonably accurate

(Appendix C).

All gaged dams had evidence of some degree of monthly flow

alteration. Among the 185 dams evaluated, each one had at

least one month in which observed monthly flows deviated from

expected values by more than 50%. For 66 dams, monthly flows

were altered by more than 50% for all 12 months, and for the

vast majority of dams (n = 171), monthly flows were altered by

50% for 6 or more months.


Figure 6

Histograms of observed/expected mean monthly flows for all gaged dams.

O/E values between 0.75-1.25 (gray bars) indicate that observed flows are

similar to expected values


Next, potential effects of dams on downstream peak flows were

assessed by comparing observed with expected values of mean

maximum 1-day flow. Only gages with more than 350 days of

daily flow records per year for 10 years were included, resulting

in 153 unique sites. Maximum 1-day flows were generally

lower than expected values, indicating a reduction in peak-flow

magnitudes below most dams (Figure 7). Of 153 sites

evaluated, observed maximum 1-day flows were less than 50%

of expected values at more than half (n = 83) of the gages.

Figure 7

Histogram of observed/expected maximum 1-day discharge. O/E

values near 1 (gray bar) indicate that observed flows are similar to

expected values

Changes in seasonal flow patterns were assessed by examining

the correlation between observed and expected monthly flows.

For the majority of gages (n = 125 of 172), observed and

expected monthly flows were strongly correlated (r > 0.75),

indicating that monthly seasonal flow patterns were largely

preserved. However, low correlation (r < 0.5) of monthly flows

below several dams provides evidence that seasonal flow

patterns have been highly altered in some rivers (Figure 8).

There were 14 gages with correlation values less 0, indicating a

reversal of natural seasonal flow patterns in those affected


rivers. An example of a dam in which downstream flows closely

follow expected seasonal patterns is the R.W. Mathews Dam on

the Mad River (r = 0.99, Figure 9). Deviation from expected

seasonal flow patterns is evident below dams such as New

Melones Dam on the Stanislaus River (r = 0.63) and Indian

Valley Dam on North Fork Cache Creek (r = 0.05)

Figure 8

Histogram of correlation coefficient between observed and expected

monthly flows, for all gages below dams. Gray bar denotes high

correlation, or strong correspondence, between observed and expected

seasonal monthly flow patterns


Figure 9

Examples of seasonal flow alteration below dams, as measured

by correlation between expected (modeled unimpaired) and

observed mean monthly flows


The impounded runoff (IR) values exhibited a bi-modal

distribution, with most dams having either values less than 0.2

(i.e., storage capacity less than 20% of annual inflow volume) or

greater than 1 (i.e., storage capacity greater than mean annual

inflow) (Figure 10). A total of 345 dams have an IR greater

than 0.5, 229 greater than 0.75, and 178 greater than 1.

Storage capacity is thus strongly correlated with expected

annual discharge, suggesting that many dams in California are

designed to capture a significant proportion of available annual

supplies. Thus, even dams that are relatively small may

capture most or all of the annual discharge of an affected river

or stream. While dams with high IR-values occur throughout

the state, they are clustered in particularly high densities in

arid regions, such as southern coastal California and the Modoc

plateau (Figure 10).

Figure 10

Impounded runoff (IR) ratio for dams in California,

representing the capacity relative to the (modeled) mean

annual inflow; inset map illustrates the difference between IR

and CIR for series of dams on the Pit River


The cumulative impounded runoff (CIR) ratio reflects the

potential effects of all dams in the catchment above a specific

dam of interest. For example, the series of dams on the Pit

River have individually low IR values (<0.1), but because they

are below Lake Almanor, a large reservoir with a high IR value

(>1), downstream flows are likely to exhibit greater

impairment than otherwise expected (inset map in Figure 10).

To evaluate how the IR and CIR relate to observed patterns of

hydrologic alteration at gaged dams, the O/E and seasonality

metrics were plotted against IR and CIR (only CIR presented,

Figure 11). There was substantial variability in the data, but

average monthly O/E values were positively correlated with

CIR, signifying that higher CIR values are associated with

increased deviation in monthly flows. In contrast, there was a

weak negative relationship between O/E maximum 1-day

values and CIR, indicating that dams with greater CIR values

tend to reduce peak flows. Pearson’s r, signifying the

correlation between observed and expected seasonal flow

patterns, was not highly correlated with CIR. However, low

values of Pearson’s r occurred more frequently at high CIR

values (>0.5) than at low CIR values, indicating that degree of

seasonal flow alteration may be higher for dams with high CIR.


Figure 11

Relationship between O/E monthly flows, O/E maximum 1-day

flows, Pearson’s r and the cumulative impounded runoff (CIR)

ratio at gaged dams


INDICATORS OF FISH CONDITION

To assess the condition of fish in river basins affected by dams,

we first evaluated the association of dams with the loss of

native species from their historic range. Based on the 28 fish

taxa for which reliable historical distribution data exists, at

least one species has been lost from 265 (HUC12) watersheds

affected by 263 dams (Figure 12). Dams associated with the

loss of species were concentrated in the central and southern

California coast, the Sierra Nevada foothills and in the upper

Sacramento and Klamath river basins. Among species with

known historic ranges, Arroyo chub, Central Coast coho

salmon, Central Valley fall Chinook salmon, and Sacramento

perch were the most common species to be lost from

watersheds affected by dams.

Figure 12

Patterns of species loss from HUC12 watersheds for 28 native

fish species with historical and current range data


The condition of native fish populations was then evaluated by

integrating range maps with the Moyle et al. (2011) population

status assessment, yielding a statewide map of sensitive taxa

richness at the HUC12-watershed scale (Figure 13). All dams

falling within range of sensitive species populations (considered

endangered or vulnerable) were then identified. The regions of

California supporting the highest richness of sensitive species

populations are the Central Valley, the Sacramento-San

Joaquin River Delta, the upper Sacramento River, and

Klamath River Basin (Figure 13).

Figure 13

Patterns of sensitive species richness within California’s

HUC12 watersheds; population status of each native species

based on Moyle et al. 2011


A total of 378 dams are within the range of at least 1 sensitive

species. Of these, 211 are within the range of anadromous ESA-

listed salmon and steelhead trout species, such as the

endangered Southern California steelhead trout (Figure 14).

Figure 14

Current distribution of anadromous salmonid species, listed as

threatened or endangered under the federal Endangered

Species Act


RELATIONSHIPS BETWEEN HYDROLOGIC

ALTERATION AND FISH CONDITION

A series of box plots were generated to explore relationships

between hydrologic variables and fish community

characteristics. First, the total richness of native fish species

was compared with hydrologic metrics for each dam. There was

a positive association between the number of native species

present and estimated annual discharge and cumulative

storage. This indicated that species richness tends to increase

with river size (Figure 15). However, there was no apparent

trend between native species richness and other indicators of

hydrologic alteration.

Figure 15

Native species richness plotted against annual discharge and

cumulative storage


Next we examined the association between the number of sensitive species present (plus any native species extirpations) and the hydrologic alteration metrics. There was substantial variation in the data for all variables, but differences among the species richness bins were generally small. The total number of sensitive and lost species was slightly greater for dams with large mean annual discharge and cumulative storage (Figure 16). In addition, dams with no sensitive species had the lowest mean value for impounded runoff, cumulative impounded runoff, and maximum 1-day flow deviation (Figure 17). Differences in sensitive species richness did not appear to vary significantly by the degree of monthly and seasonal flow deviation.

Figure 16 Number of sensitive species plus species losses, plotted against annual discharge and cumulative storage capacity


Figure 17 Number of sensitive species plus species losses, plotted against impounded runoff (IR), cumulative impounded runoff, monthly flow deviation, maximum 1-day flow deviation, and seasonal flow deviation; flow deviation metrics are transformed: increasing values (from 0) indicate increasing degree of deviation from modeled unimpaired conditions


DAMS SUBJECT TO FEDERAL

ENVIRONMENTAL FLOW REQUIREMENTS

A total of 165 dams were excluded because they are subject to

federally determined environmental flows (Figure 18). These

included 159 FERC-regulated dams and others, such as Shasta

Dam that operate under a federal biological opinion to protect

ESA-listed species.

Figure 18

Dams with (gray, n = 165) and without (black, n = 588) known

federal environmental flow requirements


IDENTIFICATION AND RANKING OF

CANDIDATE DAMS

Of the 753 dams evaluated, 385 were associated with at least

one indicator of altered downstream flows. All 185 gaged dams

had modified monthly flows (deviation greater than 50%) in at

least one month, while 91 of them were associated with

impaired maximum 1-day flows (deviation greater than 50%),

and 41 had evidence of significant seasonal flow alteration (i.e.,

weak correlation between observed and expected monthly flow

patterns). A total of 288 dams had IR or CIR values greater

than 0.75.

Among all 753 dams, 495 were associated with at least one

indicator that fish are not in good condition (e.g., loss of species

or presence of sensitive species populations). For 263 dams, at

least one species has been lost its HUC12 watershed, while a

total of 378 dams are within the range of sensitive species. A

total of 268 dams (of the 495 with indicators of fish

impairment) also had evidence of flow regime alteration.

Excluding dams with federally regulated environmental flows,

there are 220 remaining candidate dams considered high

priority for assessing compliance with Section 5937 (Appendix

D, Figure 19).

Figure 19

High priority candidate dams (n = 220) for assessing

compliance with Section 5937


To further examine the final subset, candidate dams were

ranked and sorted by their physical features (reservoir

capacity), hydrologic indicators (degree of seasonal flow

alteration), and associated fish community characteristics.

Dams with large storage capacities are ranked because of their

influence on downstream water availability for fish is likely

significant. Also, most large storage dams are designed to

control the timing and magnitude of flow releases, which could

facilitate the conjunctive management of reservoirs for

multiple benefits, including flows for fish. Dams with the

largest water storage capacities include Trinity Dam on the

Trinity River, New Melones Dam on the Stanislaus River, Pine

Flat on Kings River, and Folsom Dam on the American River

(Table 1). Dams associated with the greatest downstream

hydrologic alteration were also identified and ranked by

correlation of observed to expected mean monthly flows. Among

the subset of dams with downstream USGS gaging stations (n

= 185), Tinemaha Dam on the Owens River, Anderson Dam on

Coyote Creek, and Calaveras Dam on Calaveras Creek were

associated with the greatest alteration to seasonal monthly

flow patterns (Table 1).


Table 1 Top 20-ranking dams sorted by storage capacity and seasonal flow deviation

Rank Storage capacity (106 m3) Monthly flow deviation (r)a

1 Trinity 3,019 Tinemaha -0.55

2 New Melones 2,960 Anderson -0.03

3 Pine Flat 1,233 Calaveras -0.01

4 Folsom 1,203 Mendota Diversion

0.11

5 Warm Springs 470 Crocker Diversion 0.12

6 San Antonio 432 San Antonio 0.16

7 Nacimiento 419 Bradbury 0.23

8 Castaic 399 Nacimiento 0.27

9 New Hogan 391 Seven Oaks 0.32

10 Casitas 313 Keswick 0.37

11 Twitchell 296 Lewiston 0.45

12 Stampede 279 Lake Kaweah 0.55

13 Bradbury 253 West Valley 0.57

14 Long Valley 226 Success 0.61

15 Mathews 224 New Melones 0.62

16 Seven Oaks 180 Casitas 0.63

17 Black Butte 177 Donner Lake 0.65

18 Lake Kaweah 176 Lake O’Neill 0.70

19 Coyote Valley 151 Dwinnell Dam 0.74

20 El Capitan 139 Martis Creek 0.74 a. Assessed only at dams with downstream gages (n = 185) by

calculating the correlation between observed and expected (modeled) mean monthly flows.


Candidate dams associated with a high richness of native species and sensitive species were also identified. The highest-ranking dams are those in watersheds that support particularly high fish biodiversity. This suggests that their management would be important to native fish conservation. Dams associated with the greatest richness of native species include Woodbridge Diversion Dam on the Mokelumne River, Nash Dam on a tributary to Stillwater Creek in Shasta County, and a series of three Rubber Dams on lower Alameda Creek (Table 2). The dams associated with the greatest number of sensitive species included Keswick and Anderson-Cottonwood dams on the Sacramento River, Woodbridge Diversion Dam, and Nash Dam (Table 2).


Table 2 Top 20-ranking dams sorted by native species richness and sensitive species richness

Rank Native species richness Sensitive species richness

1 Woodbridge Diversion 10 Keswick 6

2 Nash 10 Woodbridge Diversion 6

3 Alameda Creek Rubber Dams 9 Anderson Cottonwood 6

4 Folsom 9 Nash 6

5 Nimbus 9 Folsom 5

6 Goodwin 8 San Pablo 5

7 Crocker Diversion 8 Nimbus 5

8 Farmington 8 Novato Creek 5

9 New San Leandro 8 Crocker Diversion 5

10 Woodward 7 Lake Anza 5

11 Prosser Creek 7 Englebright 4

12 Lewiston 7 Lower Crystal Springs 4

13 Chabot 7 Farmington 4

14 Clementia 7 New San Leandro 4

15 Putah Diversion 7 Woodward 4

16 La Grange 7 Modesto Reservoir 4

17 San Lorenzo Creek (Don Castro) 7 San Andreas 4

18 Rodden Lake 7 Lewiston 4

19 Hamel 7 Chabot 4

20 Dry Creek 7 Guadalupe 4

Dams were also identified within the range of ESA-listed salmon and steelhead trout species (Table 3). The list does not include all dams within the species ranges – just those in the final subset of candidate dams. Only four candidate dams are within the range of Southern Oregon/Northern California coho salmon (ESA endangered): Trinity and Lewiston Dams on the Trinity River, Dwinnell Dam on the Shasta River, and Scout Lake Dam on a tributary to Berry Creek in Mendocino County.

Dams located within the range of ESA-endangered Central California Coast coho salmon are: Warm Springs Dam on Dry Creek in Sonoma County, Peters, Bon Tempe and Alpine Dams in the Lagunitas Creek watershed, Soulajule Dam on Arroyo Sausal (also in Marin County), and Newell Dam on the San Lorenzo River in Santa Cruz County.


These dams are also within the range of ESA-threatened

Central California Coast Steelhead Trout, as are San Antonio

Dam on the San Antonio River in Monterey County,

Nacimiento Dam on the Nacimiento River in San Luis Obispo

County, and Coyote Valley Dam on the east fork of the Russian

River in Mendocino County.

The largest dams potentially affecting Southern California

steelhead trout (ESA endangered) are Casitas, Twitchell, and

Bradbury Dams – on Coyote Creek, Cuyama River, and Santa

Ynez River, respectively. There are 20 candidate dams within

the range Central Valley steelhead trout (ESA threatened).

The largest are Folsom, New Hogan, Black Butte, and

Englebright.


Table 3 Top 20-ranking dams sorted by ESA-listed salmon and steelhead trout populations

Southern Oregon/Northern California Coho

Central California Coast

Coho Salmon

Central California Coast Steelhead Trouta

Southern California

Steelhead Trout

Central Valley Steelhead Trout

Trinity Warm Springs Warm Springs Casitas Folsom

Dwinnell Dam Peters San Antonio Twitchell New Hogan Dam

Lewiston Soulajule Nacimiento Bradbury Black Butte

Scout Lake Alpine Coyote Valley El Capitan Englebright

Newell Calaveras San Vicente Modesto Reservoir

Bon Tempe Anderson Whittier Narrows

Keswick

Bean Hollow #2 Lower Crystal Springs

Morena Nimbus

Lopez Barrett Anthony House

James H Turner San Gabriel Woodbridge Diversion

San Pablo Lake Hodges Davis No 2

New San Leandro Bouquet Canyon Anderson

Cottonwood

Whale Rock Santa Fe Clementia

Peters Morris Putah Diversion

Conn Creek Ramona Goodwin

Salinas Wood Ranch La Grange

San Andreas Gibraltar Nash

Hernandez Juncal Rodden Lake

Lake Curry Trampas Canyon Hamel

Soulajule Mission Viejo Crocker

Diversion

Chabot Upper Oso Foothill Ranch a Top 20 largest (by storage capacity) of 48 candidate dams that occur within the range of Central California Coast steelhead trout.


In summary, 220 dams were identified as sites where improved environmental flows are likely warranted under Section 5937, based on evidence of hydrologic alteration and indicators of fish population impairment. These dams are statewide (Figure 19) and represent a broad diversity of ownership (e.g., public utilities, private, state agencies), impoundment sizes and functions (e.g., flood control, water storage, and diversions). None is regulated by FERC, although some are subject to environmental flow requirements of federal or state agencies. Regardless, it is unknown whether flow releases from any of the candidate dams are managed to keep fish in good condition. While this analysis provides evidence of flow regime alteration and fish population impairment for all candidate dams, determination of Section 5937 compliance will likely require site-specific assessment.

PRELIMINARY SITE INVESTIGATIONS

We present 10 of the candidate dams as case studies to how operations may affect fish downstream (Table 4, Figure 20). The case-study dams are not necessarily those most in need of improved flows for fish. Rather, they serve to highlight the broad diversity of dams in California, in terms of their size, location, ownership, and function. Many of the case dams were selected from the ranked lists (Tables 1-3). In Chapter V, we describe for each of the 10 dams basic structural and operational characteristics, the downstream flow regime, and native fish species potentially affected.


Table 4 Case study dams

Dam County River Capacity (106 m3)

Ownership Primary Purpose

Sensitive species potentially affected

Black Butte Dam Tehama Stony Creek 177.3 Army Corps

of Engineers

Flood control and irrigation

Central Valley steelhead, Central Valley fall-run and spring-run Chinook

Conn Creek Dam

Napa Conn Creek 38.2 City of Napa Urban water supply

Central California coast steelhead trout

Peters Dam Marin Lagunitas Creek 40.5

Marin Municipal Water District

Urban water supply

Central California coast coho salmon, Central California coast steelhead

Woodbridge Diversion Dam

San Joaquin

Mokelumne River

3.0

Woodbridge Irrigation District

Recreation, irrigation and urban water supply

Central Valley steelhead, Central Valley fall-run Chinook salmon, southern green sturgeon, white sturgeon

Twitchell Dam

San Luis Obispo

Cuyama River 296 Bureau of

Reclamation Irrigation Southern California coast steelhead trout, Arroyo chub

Long Valley Mono Owens River 226.3 City of Los Angeles

Hydroelectric and water supply

Owens tui chub, Owens speckled dace, Owens pupfish

Casitas Dam Ventura Coyote Creek 313.3 Bureau of Reclamation

Irrigation and water supply

Southern California coast steelhead, Arroyo chub

Boles Meadow Dam

Modoc Boles Creek 6.2 Forest Service

Irrigation

Shortnose sucker, Lost River sucker, Klamath largescale sucker, Klamath marbled sculpin

Pine Flat Dam Fresno Kings River 1,233.5 Army Corps

of Engineers Flood control Kern brook lamprey

Dwinnell Dam Siskiyou Shasta River 61.6

Montague Water Conservation District

Irrigation

Southern Oregon/Northern California coho salmon, Upper Klamath-Trinity fall- and spring-run Chinook salmon


Figure 20

Ten case study dams from the list of candidate dams (n = 220),

selected to provide preliminary site investigation of the

potential effects of dam operations on downstream fish

DISCUSSION | 47

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DISCUSSION

SYSTEMATIC EVALUATION OF DAMS

This study offers a systematic framework for identifying dams

that likely need improved downstream fish flows as required

under Section 5937. From an original pool of more than 1,400

dams, we identified 220 as high-priority candidates for further

investigation of environmental flow needs for fish. These dams

fall within a broad range of biogeographic settings and

represent a wide diversity in size, function and ownership.

For the vast majority of dams, flows observed at downstream

gages deviated from expected natural patterns by at least 50%

for at least six months of the year. In addition, for more than

half of the gaged dams evaluated, maximum 1-day flows were

less than 50% of predicted values. While model prediction error

of expected flows could be contributing to apparent deviation

from observed values, the lack of model bias (Appendix C) and

magnitude of effects among gaged dams suggests that the

deviation reflects true impacts of dam operations. Although

several dams appear to have substantially altered seasonal

flow patterns, flow seasonality has been largely preserved

below the majority of gaged dams. This may be the result of

water spilling over dams in winter and minimum flow releases

in the summer, likely to provide water for downstream water

rights holders.

The lack of gaging records restricted the hydrologic impact

analysis to a relatively small subset of dams (about 200).

However, the correlation between O/E- and seasonal flow

alteration metrics indicates that the impounded runoff ratio is

a reasonable proxy for predicting potential hydrologic

alteration below dams. Thus, large IR values for many dams in

the state suggest that alteration to downstream flows is likely.

A significant proportion of the dams assessed are within the

range of least one native fish species considered at risk of

extinction. A total of 378 dams (of the 753 assessed) are within

the range of at least one sensitive fish species, including 211

within the range of ESA-listed anadromous salmonids.

DISCUSSION | 49

Furthermore, at least one native fish species has been lost from

watersheds affected by 263 of the 753 dams.

There is some evidence that the number of sensitive species

and species losses is associated with hydrologic alteration

below dams. For example, dams with no sensitive species or

extirpations tended to have lower deviation values in

maximum 1-day flows and lower impounded and cumulative

impounded runoff than dams with 1 or more sensitive species

and extirpations. While the association of dams with sensitive

fish populations or reduced species ranges is not causal

evidence, the potential for dams to impair fish populations is

well-established in California (e.g., Marchetti and Moyle 2001;

Brown and Ford 2002; Brown & Bauer 2010; Moyle et al. 2011)

and elsewhere (e.g., Gehrke and Harris 2001; Clavero et al.

2004; Rinne et al. 2005). Thus, it is reasonable to expect that

dam operations are an important influence on the condition

and persistence of fish populations.

LIMITATIONS

The investigation revealed a notably lack of information

detailing dam operations, downstream flow regimes, and

affected fish communities. The void presented a major

challenge in building a standardized, high-resolution database

of California dams and associated conditions. The National

Inventory of Dams (USACE 2012) and State Jurisdictional

Dam Database (DWR 2010) provided dimensions, location, and

ownership of dams, but none of the operational information

needed to effects on downstream flows. The vast majority of

dams have no flow monitoring downstream. In those cases, we

used the impounded runoff index as a proxy for hydrologic

alteration.

The effects of California’s dams on downstream flows remains

poorly documented. The study not only highlights the need for

improved stream flow monitoring, but also for public reporting

of dam operations and water use. To quantify potential

hydrologic effects of diversion dams (which generally have a

small storage capacity, but may divert substantial volumes of

water), we examined the Water Rights Database of the State

Water Resources Control Board (SWRCB 2012). This database

includes coordinate locations for all points of diversion linked


to the project’s water rights permit or license. But the database

was not useful for quantifying the hydrologic effects of

diversions because there was little concurrence between the

face value of water rights and actual water use (e.g. assessed at

flow gage or from secondary data source). The lack of accurate

reporting of water use represents a significant impediment to

managing for environmental flows in California’s rivers.

The UC Davis PISCES database (Viers et al. 2012) is the most

comprehensive compilation of standardized data on California’s

native fish species. PISCES is a software and data storage

platform that uses primary source data, modeling, and expert

analysis to generate best-known ranges for the state’s fish. But

data are compiled and presented at the HUC12 watershed

scale, making it impossible to distinguish between fish

assemblages below and above dams. Thus, the spatial

association of fish species with specific dams (upon which the

selection criteria are based) is not definitive; indicators of fish

community impairment (e.g. sensitive species or loss of species

from historic range) below dams should be confirmed as part of

site-specific investigations.

RECOMMENDATIONS

Our evaluation approach can be improved as new data and

modeling tools become available. Additional monitoring data on

downstream flows and fish communities could change the

relative rankings of dams on the high-priority list. New criteria

could also be incorporated in the evaluation framework to

support the selection and ranking of high-priority dams for

further assessment. For example, criteria based on the quality

and quantity of downstream available fish habitat would help

prioritize dams for environmental flow management. There is a

broad suite of additional indicators of hydrologic alteration that

could also be assessed below gaged dams (Olden and Poff 2003).

Also, information on the relative vulnerability of California’s

fish assemblages to climate change is needed for informing

environmental flow implementation strategies. Most dammed

rivers in California support native fish species considered

highly vulnerable to climate change (Moyle et al. 2012). For

example, the availability of suitable habitat for many cold-

water species such as salmon is likely to decrease in the future

DISCUSSION | 51

(Katz et al. 2012; Null et al. 2013). Modification of flow releases

from dams to maintain cold-water habitat could be an

important tool to reduce impacts of climate change on fishes.

The integrated database developed for this study can be used to

examine the relationships between physical drivers of river

alteration and ecological responses. In this study, associations

between hydrological metrics and indicators of fish condition

were examined through qualitative, exploratory analysis.

While not conclusive or exhaustive, these relationships are

strong indicators of the linkage between dam-driven flow

changes and fish condition, and highlight the need for more

robust, statistical analyses to quantify the effects of dam

operations on California’s native fish assemblages. Such

analyses could be helpful in developing environmental flow

recommendations for regulated rivers throughout the state and

elsewhere.

In summary, there is evidence that flows below many of

California’s dams may be insufficient to maintain fish in good

condition. Given the rapid decline of California’s fish fauna and

pervasive alteration to the state’s river ecosystems,

environmental flows are important if not critical to

conservation of many native fish populations. Section 5937

requires that such flows be restored and protected. Other

states and countries have similar legal mechanisms for

protecting environmental flows (Annear et al. 2004; Arthington

2012; Gillilan and Brown 1997), including the Public Trust

Doctrine (Frank 2012), of which 5937 could be regarded as an

extension (Börk et al. 2012). Thus, our evaluation method is

applicable beyond California where systematic assessments of

dams could help guide the management and conservation of

freshwater ecosystems.


CASE STUDIES

Ten case study dams were selected from the 220 candidate

dams associated with evidence of flow alteration and fish

population impairment. Several dams were selected for their

potential impacts to ESA-listed salmon and steelhead trout:

Black Butte Dam on Stony Creek was selected because

of its location in the upper Sacramento River basin and

potential effects on Central Valley fall- and spring-run

Chinook salmon and Central Valley steelhead trout.

Conn Creek Dam is a smaller dam in the Napa River

watershed managed for municipal water supply and has

the potential to affect Central California coast steelhead

trout populations.

Peters Dam, which is also managed for municipal water

supply, affects populations of Central California coast

coho salmon and steelhead trout.

Dwinnell Dam on the Shasta River potentially affects

populations of Southern Oregon/Northern California

coho salmon.

Casitas Dam and Twitchell Dams within the range of

Southern California steelhead trout.

Other dams were selected to illustrate a diversity of operations

and management objectives:

Woodbridge Diversion Dam on the Mokelumne River

was selected to highlight potential impacts of water

diversion facilities. Diversion dams often have low

water storage capacities, but may divert substantial

amounts of water that would otherwise flow

downstream. Woodbridge also illustrates the effect of

upstream dams on local operations

Long Valley Dam on the Owens River impounds

municipal water supplies imported from Mono Lake

Basin. Though outside the range of anadromous fishes,

the potentially affects several highly endemic and

threatened native fish species.

Boles Meadow Dam on Boles Creek impounds a small

(6.2×106 m3; 5,000 acre feet), seasonal reservoir that is

managed for livestock forage. The creek also supports a

highly endemic and threatened natiuve fish fauna.

Pine Flat Dam on the Kings River impounds one of the

state’s largest reservoirs [more than 12,000×106 m3

(1,000,000 acre feet)] and is operated for multiple

benefits, including flood control and agricultural water

supply.

CASE STUDIES | 53

CASE STUDY 1: BLACK BUTTE DAM

Black Butte dam is in Tehama County (Figure 21) and

captures runoff from upper Stony Creek (1,916 km2), which

drains the eastern slope of the Coast Range and flows into the

Sacramento River, near Hamilton City. The 48-meter (156-ft)

earthen dam was built in 1963 and is owned and operated by

the USACE. Its operations are also coordinated with the US

Bureau of Reclamation’s (USBR) Central Valley Project and

the Orland Project, which has several water storage and

diversion dams in the Stony Creek watershed.

Figure 21

Black Butte Dam and catchment (1,916 km2) on Stony Creek.

Downstream flows were evaluated at USGS gage #11388000

below the dam


Aerial view of Black Butte Dam in Tehama County. Source: Army Corps of Engineers Digital Visual

Library

Black Butte Dam is managed for flood control, recreation, and

water supply. The dam impounds Black Butte Reservoir, with a

total storage capacity of about 177×106 m3 (144,000 acre feet).

A small re-regulating dam is immediately downstream. Several

large dams are upstream of Black Butte Dam within the Stony

Creek watershed, including East Park Dam and Stony Gorge

Dam.

Black Butte Dam was included on the list of candidate dams

because of observed deviation in expected monthly flows, its

high cumulative impounded runoff ratio, and potential to affect

threatened populations Central Valley Chinook salmon,

Central Valley steelhead trout, and other sensitive fish species

(Table 5).

CASE STUDIES | 55

Table 6

Black Butte Dam on Stony Creek, Tehama County

Black Butte Dam

Physical

Characteristics

Dam height: 48 m

Reservoir capacity: 1.77×108 m

3

Catchment area: 1,916 km2

Mean annual inflow: 6.11×108 m

3

Hydrologic Alteration Impounded runoff (IR) ratio: 0.29 ; Cumulative IR ratio: 0.50

Observed flows at downstream gage indicate a significant reduction in peak 1-day flows,

enhanced summer flows and reduced late fall flows. Monthly flows follow expected

seasonal patterns (r = 0.94)

Condition of

Downstream Fish

Sensitive species potentially affected below dam: Central Valley fall-run, late fall-run,

winter-run and spring-run Chinook salmon, Central Valley steelhead trout, and hardhead

Low-flows and degraded habitat conditions may adversely affect condition of

downstream native fish populations.

HYDROLOGIC CONDITIONS

Flow releases from Black Butte dam are primarily controlled

for flood control and irrigation purposes. The reservoir is also

managed for boating and a warm-water fishery. The USBR

operates the dam April to October for irrigation and the

USACE manages it for flood control from November to March

(H.T. Harvey & Associates 2007).

The unimpaired annual inflow to Stony Creek at Black Butte

Dam is about 6×109 m3 (50,000 acre feet), yielding an

impounded runoff ratio of 0.29. When accounting for the

capacity of upstream dams, the cumulative impounded runoff

ratio at the dam is 0.50.

Flows observed at the USGS gage below Black Butte Dam

(#11388000) were compared with modeled unimpaired

hydrologic metrics. Mean annual flow below Black Butte is

about 80% of its expected value, a reflection of irrigation

diversions. Observed mean monthly flows (1970-1990) from

January to May were slightly lower than modeled unimpaired

flows, with observed-to-expected (O/E) ratios generally between

0.75 and 1.0 (Figure 22). Observed flows were similar to

expected values in June and July (O/E ≈1), but were

substantially higher in August and September (O/E >1.5). In

the fall, mean flows below the dam were lower than expected,


with O/E values of 0.44 in October, 0.29 in November, and 0.64

in December. Maximum 1-day peak flows have been

significantly reduced, with an O/E value of 0.60. There is no

evidence that flow seasonality has been altered, with observed

monthly flows following expected seasonal patterns (r = 0.94).

Figure 22

Expected (E, modeled) and observed (O) mean monthly flows

below Black Butte Dam and the O/E ratio

CONDITION OF DOWNSTREAM FISH POPULATIONS

Stony Creek historically supported Central Valley steelhead

and spring and fall runs of Central Valley Chinook salmon.

Black Butte dam completely blocked anadromous fish

migration to the upper Stony Creek watershed. However,

steelhead and Chinook salmon and other native fish species

have been observed in lower Stony Creek, in addition to several

non-native species (H.T. Harvey & Associates 2007). Sensitive

fish species potentially affected by management operations

downstream of Black Butte Dam include Central Valley fall-

run (Status 2), late fall-run (Status 1), and spring-run Chinook

salmon (Status 2, ESA-listed as threatened), and Central

Valley steelhead (Status 2, ESA-listed as threatened). Stony

Creek may also be important for spawning of Sacramento

CASE STUDIES | 57

sucker, Sacramento pikeminnow, and hardhead and other

native fishes moving up from the Sacramento River during

high flows in spring.

MANAGEMENT OF DOWNSTREAM FLOWS FOR FISH

Black Butte Dam is operated to control downstream flooding

and erosion in winter, and to supply irrigated farms in the

summer. An Incidental Take Permit for ESA-listed salmonids

in lower Stony Creek limits flood control ramping rates and

minimum flow releases during the spawning period (NMFS

2008). Also, spring flow releases for salmon and steelhead are

negotiated each year, based on water storage levels in Black

Butte Reservoir and upstream reservoirs in the basin.

Nevertheless, stream flows from late fall through spring are

consistently less than levels (approximately 10-30 m3/s [400-

1,000 ft3/s]) required for spawning and incubation and to

support rearing of fall-run Chinook salmon juveniles (H.T.

Harvey & Associates 2007, p. 54). Low flows in the late fall are

likely a critical limiting factor to salmon and other native fish

taxa in lower Stony Creek.

A recent fish habitat assessment of Lower Stony Creek

reported that “opportunistic use” by salmonids of Stony Creek

is limited spatially and temporally because of their life cycle,

the water temperature and stream flow (H.T. Harvey &

Associates 2007, p. 56). Passage barriers, diversions, habitat

degradation, and altered flow regimes also inhibit salmon

recovery in the creek (NMFS 2008).


CASE STUDY 2: CONN CREEK DAM

Conn Creek Dam is about 12 km (7.5 mi) upstream from the mouth of Conn Creek at its confluence with the Napa River in Napa County (Figure 23). The 38-m (125-ft) high earthen dam impounds Lake Hennessey, which has a storage capacity of 38.2×106 m3 (31,000 acre feet) and is the largest reservoir in the Napa River watershed.

Figure 23 Conn Creek Dam and catchment on Conn Creek, a tributary to Napa Creek in Sonoma County. Downstream flows were evaluated at USGS gage #11456500

CASE STUDIES | 59

Conn Creek dam was built in 1948 by the City of Napa, which

uses the reservoir as its primary municipal water source.

Water is delivered to the city through the Conn Transmission

Main pipeline. Although the dam was originally authorized as

a flood control project, its operation for water supply typically

results in high storage volumes and limited flood storage

capacity. When the reservoir at capacity, excess flows drain

from a spillway into lower Conn Creek. The dam does not have

gateways or infrastructure elements to allow for controlled

water releases. Conn Creek Dam was included on the list of

candidate dams for its high impounded runoff ratio and

potential to affect a population of threatened Central California

coast steelhead trout (Table 6).

Conn Creek Dam in Napa County. Source: T. Grantham


Table 7

Conn Creek Dam on Conn Creek, Napa County

Conn Creek Dam

Physical Characteristics

Dam height: 38 m

Reservoir capacity: 38.2×106 m3

Catchment area: 135 km2

Mean annual inflow: 24.3×106 m3 (City of Napa, 2006); 54.2×106 m3 (model)

Hydrologic Alteration

IR: 1.6, Cumulative IR: 1.6

Historic downstream flow gage indicates that natural stream drying may have

occurred later in the year than under present conditions. Conn Creek below

the dam currently does not have a flow gage.

Condition of Downstream Fish

Sensitive species potentially affected below dam: Central California coast

steelhead trout

Lack of perennial flows, low-flows, and degraded habitat conditions may

adversely affect condition of downstream native fish populations.


Mean annual inflow to Conn Creek Dam was predicted by the

hydrologic model to be 54.2×106 m3 per year. The city’s water

management reports estimate annual inflows at 24.3×106 m3,

based on hydrologic analysis of local empirical data. Using the

local estimate, Lake Hennessey (with a storage capacity of

38.2×106 m3) has an impounded runoff index of 1.6.

Flow records from a pre-dam USGS gage (#11456500) indicate

a rainfall-runoff dominated hydrograph, with peak flows

between January and March, followed by a low-flow period

between April and November. The creek typically has

intermittent flows by July and was dry from September to

October, except for a few large pools. A recent stream inventory

by the Napa County Resource Conservation District (Napa

RCD) reported that seasonal drying of the entire channel below

the dam typically occurred by mid-June (Napa RCD 2005),

indicating that dam operations have resulted in lower flows in

the dry season. Napa maintains storage volumes near capacity

for water supply reliability. Therefore, the dam presumably

does not reduce peak winter flows.

CASE STUDIES | 61


Conn Creek historically supported a run of Central California

coast steelhead trout, but construction of the dam cut off access

to spawning and rearing grounds in upper Conn Creek and its

tributaries. Chinook salmon may have historically used the

low-gradient reaches of Conn Creek for spawning and rearing.

Pacific lamprey was also historically present in the Conn Creek

watershed (Murphy 1949). Chinook salmon continue to spawn

in the Napa River near the confluence with Conn Creek, and

intermittently flowing reaches of lower Conn Creek may be

used opportunistically for spawning (Napa RCD 2005). Conn

Creek below the dam currently provides limited habitat for fish

because of the absence of perennial flows, habitat degradation,

and high summer water temperatures. Lower Conn Creek

lacks summer habitat for rearing of steelhead. More tolerant

native species, mainly California roach, persist in the few large

pools that remain wet through the summer (Napa RCD 2005).

Unlike steelhead, which require a year or more of stream

residence, Chinook parr may successfully out-migrate from the

creek in late spring prior to seasonal drying (Napa RCD 2005).


Most of the water stored behind Conn Creek Dam is diverted to

the City of Napa. According to the city’s Urban Water

Management Plan, about 21.5×106 m3 (or 90%) of the annual

water yield at the dam is diverted (City of Napa 2006). The

Plan states that the City is required to provide “sufficient

releases from the reservoir to provide minimum stream flows

but these requirements do not significantly affect supply

reliability” (City of Napa 2006, p. 4-6). However, flows below

Conn Creek Dam are not monitored and the quantity of

downstream flows provided for fish is unknown.


CASE STUDY 3: PETERS DAM

Peters Dam is in the Lagunitas Creek watershed (267 km2),

which drains the western slope of the Coast Range into the

Pacific Ocean at Tomales Bay, in western Marin County

(Figure 24). The dam impounds Lagunitas Creek to form Kent

Lake. The Marin Municipal Water District (MMWD) manages

the dam and several other reservoirs in the watershed to

supply Marin County residents. Built in 1953, Peters Dam was

raised by 13 meters in 1982 to increase water storage capacity

to 40.5×106 m3 (33,000 acre feet), making it the largest

reservoir in the watershed. Peters Dam was included on the

list of candidate dams for its high impounded runoff ratio and

potential to affect sensitive species in the Lagunitas Creek

watershed, including Central Coast coho salmon and Central

California coast steelhead trout (Table 7).

Figure 24

Peters Dam and upstream catchment (267 km2) on Lagunitas

Creek in Marin County. Downstream Flows were evaluated at

USGS gage #11460400

CASE STUDIES | 63

Kent Lake and Peters Dam in Marin County. Source: K. Manohar.

Table 8

Peters Dam on Lagunitas Creek, Marin County

Peters Dam


Dam height: 70 m



Mean annual inflow: 29.5×106 m3



Observed flows at gage indicate that flows are slightly lower than under

(modeled) natural conditions for most months, but that seasonal flow

patterns are preserved.


Sensitive species potentially affected below dam: Central California coast

coho salmon, Central coast steelhead trout.

Flows are managed under an inter-agency agreement to support life history

cycles of anadromous salmon and steelhead trout, and other endangered

aquatic species. Degraded habitat conditions may be a primarily limiting

factor for native fish populations downstream of the dam.



Flows in Lagunitas Creek are primarily controlled by releases

from Peters Dam and natural inflow from tributaries, including

San Geronimo and Devil’s Gulch creeks. Annual inflow is

approximately 29.5×106 m3 per year, yielding impounded runoff

values of 1.3. When accounting for the storage capacity of dams

above Peters, the cumulative impounded runoff value is 1.9.

This indicates that the reservoirs have the capacity to

cumulatively store about twice the mean annual runoff of the

upper Lagunitas Creek watershed.

Comparing modeled unimpaired hydrologic metrics with flows

observed at USGS gage #11460400 below Peters Dam, mean

monthly flows were slightly lower than expected values (O/E

>0.7) from December to June and higher than expected (O/E

=1.22 – 2.18) from July to October (Figure 25). Observed

November monthly flows were about half (O/E =0.5) of expected

values. Managed water releases and natural spillover events

and unimpaired tributary inflows appear to maintain a

seasonal hydrography in Lagunitas Creek that is similar to

historic conditions (r = 0.97).

Figure 25

Expected (E, modeled) and observed monthly flow below Peters

Dam on Lagunitas Creek

CASE STUDIES | 65


Lagunitas Creek watershed supports the largest remaining

wild population of Central California Coast coho salmon

(Status 1, ESA endangered) and an important population of

Central California Coast steelhead trout (Status 2, ESA-listed

as threatened). Lagunitas Creek also has one of the largest

extant populations of California freshwater shrimp (ESA

endangered), a species endemic to Marin, Napa and Sonoma

Counties. Peters and other dams in the watershed have blocked

anadromous salmonid fish passage to about 50% of their

historically available habitat (MMWD 2011). Coho and

steelhead continue to use 24 km (15 mi) of the creek below the

dam and all accessible tributaries for spawning and rearing.

The stream retains a complete native fish assemblage with

relatively low numbers of non-native fish. Native fish species in

the watershed include California roach, Sacramento sucker,

three-spine stickleback, Pacific lamprey and at least two

sculpin species.


The raising of Peters Dam in 1982 required State Water

Resources Control Board (SWRCB) approval. Following 15

years of study and negotiations, the SWRCB issued Order

WR95-17, which required MMWD to mitigate potential impacts

to Lagunitas Creek fish. Pursuant to the order, the district

maintains streamflow below Peters Dam to protect all life

stages of coho salmon, steelhead, and California freshwater

shrimp. Instream flow requirements are evaluated at the

Samuel P. Taylor Park USGS gage #11460400 (Figure 21).

During normal water years, minimum flow requirements range

from 0.2 – 0.7 m3/s (8 – 25 ft3/s) (MMWD 2011). Because San

Geronimo Creek enters Lagunitas Creek upstream of the gage,

instream flow requirements may be met in part from these

natural inflows, thus reducing the need to release water from

Peters Dam. In the winter, substantial inflow from San

Geronimo Creek makes it possible to maintain minimum

releases from Peters Dam at 0.03 m3/s (1 ft3/s). In the summer,

however, San Geronimo Creek flows are low (<0.03 m3/s)

resulting in Peters Dam releasing virtually all flow in

Lagunitas Creek (G. Andrew, personal communication).


The managed flows release water from deep in Kent Lake and

provide a consistent source of cold (<20 ºC) water for the creek,

which helps maintain conditions suitable for rearing juvenile

coho salmon and steelhead. In addition to minimum flow

requirements that vary by season, four “upstream migration

flows” of at least 1 m3/s (35 ft3/s) for three consecutive days

must be provided between November and February of each

year to provide for the upstream migration of adult

anadromous fish.

Stream habitat degradation resulting from historic logging,

along with more recent fine sediment loading and wood

removal have been identified as important limiting factors to

coho salmon and steelhead populations throughout the

watershed (Stillwater Sciences 2008). As a result, MMWD,

other agencies and local watershed groups are enhancing

habitat with placement of large wood in the stream, erosion

control/sediment reduction measures, riparian vegetation

management, and fish passage improvements in the San

Geronimo Creek drainage (MMWD 2011).

CASE STUDIES | 67

CASE STUDY 4: WOODBRIDGE DIVERSION

DAM

Woodbridge Diversion Dam is on the lower Mokelumne River

in Lodi, San Joaquin County (Figure 25). The 10-m (33-ft) high

dam impounds Lodi Lake, a 3.0×106 m3 (2,400 acre-foot)

recreational reservoir. Water is diverted at the dam to the

Woodbridge Irrigation District (WID) Diversion Canal. The

dam was built in 1910 for irrigated agriculture around Lodi.

Since the early 1990s, agricultural water deliveries by WID

have gradually been transferred to municipal water utilities.

The dam was re-built between 2006 and 2008 to improve fish

passage and increase flexibility in diversion-intake and

downstream flow-release operations.

Figure 26

Woodbridge Diversion Dam and catchment (1,682 km2) on the

Mokelumne River, San Joaquin County; inset map shows large

upstream dams and USGS gages above the dams (#11319500),

below Camanche Dam (#11323500), and below Woodbridge

Dam (#11325500)


Woodbridge Dam was included on the list of candidate dams for

its high cumulative impounded runoff ratio, evidence of

monthly and peak flow alteration and its potential to affect

sensitive populations of Central Valley Chinook salmon and

Central Valley steelhead (Table 8).

Woodbridge Diversion Dam on the Mokelumne River, San Joaquin County. Source: G. Wright.

CASE STUDIES | 69

Table 8

Woodbridge Diversion Dam on the Mokelumne River, San Joaquin County


Mokelumne River inflows to Woodbridge are completely

regulated by large upstream dams. The total storage capacity

of Camanche Dam (5.2×108 m3), Pardee Dam (2.6×108 m3), Salt

Springs Dam (1.8×108 m3), and other smaller dams upstream of

Woodbridge is 10.5×108 m3, equivalent to 110% of the

Mokelumne’s annual flow. The East Bay Municipal Water

District (EBMUD) operates Pardee Dam in conjunction with

Camanche Dam for flood control and water supply for Oakland,

Berkeley, and other San Francisco Bay Area communities.

EBMUD has a water right to divert up to 325 million gallons

per day, or up to 4.5×108 m3 per year, from the Mokelumne

River at Pardee Dam. Based on flows measured at USGS

stations above and below Pardee Dam, 30% (or 2.5×108 m3) of

annual inflow of the Mokelumne River is diverted on average

(1963-2011). An additional 1.9×108 m3 is diverted from the

river at Woodbridge Dam. As a result, observed annual flow

below Woodbridge is approximately 50% of the river’s natural

unimpaired flow. The operation of Woodbridge and larger

upstream dams has resulted in significant reduction in annual

discharge, lower peak flows, and decreased flow variability.

Woodbridge Diversion Dam


Dam height: 10 m





IR: <0.01, Cumulative IR: 1.1

Flows are substantially lower than natural conditions in the winter and

spring because of large upstream dam and diversion operations. Peak flows

have also been greatly reduced. Despite the overall reduction in flow

magnitudes, monthly seasonal flow patterns have been preserved.


Sensitive species potentially below dam: fall-run Central Valley Chinook

salmon, Central Valley steelhead, southern green and white sturgeon.

Low-flows and associated water quality degradation limit successful rearing

of juvenile anadromous fish below dam.


This is illustrated by the 2010 hydrograph at USGS gages

upstream of Pardee Dam, downstream of Camanche Dam, and

downstream of Woodbridge (Figure 27).

Figure 27

Observed daily discharge in the Mokelumne River for the 2010

water year, above Pardee Dam, downstream of Camanche Dam,

and below Woodbridge Dam

Overall, flows in the Mokelumne River below Woodbridge Dam

are controlled at lower and more stable levels than occurred

under natural conditions. Observed mean monthly flows in the

winter and spring (Jan – Jun) are about 50% of expected values

(Figure 27), and are closer to expected values in October and

November during the river’s natural low-flow period. Although

flows have been substantially reduced below Woodbridge, the

correlation between observed and expected monthly flows is

high (r = 0.95), indicating that general seasonal patterns in

monthly flows are preserved, albeit at substantially lower

magnitudes (Figure 28). The observed maximum annual 1-day

flood is about 25% of the expected values. The significant

decrease in flood flow magnitudes in the lower Mokelumne is

consistent with reports in previous studies. Kondolf and

Batalla (2005) found that the Q2 (2-year return interval flood)

has been reduced by 80% and the Q10 by 75% after

construction of major dams on the Mokelumne River; and Merz

and Setka (2004) determined that after the construction of

CASE STUDIES | 71

Camanche Dam, annual peak flows have never exceeded 200

m3/s, while pre-dam peak flows were greater than 200 m3/s in

21 of 57 years.

Figure 28

Expected (E, modeled) and observed mean monthly flow below

Woodbridge Dam on the Mokelumne River


Sensitive fish species potentially affected by operations at

Woodbridge Dam include Central Valley fall-run Chinook

salmon (Status 2) and Central Valley steelhead (Status 2, ESA-

listed as threatened). Southern green sturgeon (Acipenser

medirostris, Status 1, ESA-listed as threatened) and white

sturgeon (Acipenser transmontanus, Status 2) may also be

present. Populations of Central Valley Chinook salmon and

hatchery steelhead are the subject of on-going monitoring and

restoration efforts. They are maintained by artificial

production at the Mokelumne River Fish Hatchery at

Camanche Dam, an impassable barrier. A fish passage facility

at Woodbridge Dam allows access to salmon and steelhead

spawning habitat below Camanche.

Rearing of juvenile steelhead trout has been observed in wet

years, when flow releases below Woodbridge are greatest

(NMFS 2002). But in dry years, downstream habitat conditions

are so poor that out-migrating juvenile salmon smolts are


captured at Woodbridge and transported by truck to a release

location in the Delta. Habitat and flow alterations in the lower

Mokelumne have promoted non-native species such as western

mosquito fish (Gambusia affinis), golden shiner (Notemigonus

crysoleucas), spotted bass (Micropterus punctulatus) and

striped bass (Morone saxatilis). Abundant native species

include Sacramento sucker (Catostomus occidentalis),

Sacramento pikeminnow (Ptychocheilus grandis), tule perch

(Hysterocarpus traski), and prickly sculpin (Cottus asper). The

combined diversity of native and non-native fish species in the

Mokelumne River is greatest in the reaches below Woodbridge

Dam, presumably because of the effects of tidal action and

influence of tributary waterways (Merz and Saldate 2004).


Flow releases to the Mokelumne River below Camanche and

Woodbridge Dams are dictated in a 1998 Joint Settlement

Agreement (JSA) between EBMUD, U.S. Fish and Wildlife

Service and California Department of Fish and Wildlife.

Minimum required flow releases are designed to support

anadromous salmon, including adult upstream passage and

outmigration of juveniles. The amount of water released at

Camanche (and diverted at Woodbridge) depends on the season

and the water year. Based on a 10-year review of the JSA,

actual flows have always exceeded the required releases below

Camanche and Woodbridge dams (EBMUD et al. 2008).

However, low summer flows, high water temperatures, and

degraded habitat limit salmonids in most years.

CASE STUDIES | 73

CASE STUDY 5. TWITCHELL DAM

Twitchell Dam is on the Cuyama River, a tributary to the

Santa Maria River in southern San Luis Obispo and northern

Santa Barbara counties (Figure 29). The dam impounds the

290×106 m3 (235,000 acre feet) Twitchell Reservoir. The Bureau

of Reclamation built the dam in 1956 for water conservation,

irrigation, and flood control. It was designed primarily to

provide relatively short-term storage and releases of flows from

the Cuyama River to replenish the Santa Maria Valley

groundwater basin. The dam is operated by Santa Maria Valley

Water Conservation District. It was included on the list of

candidate dams for its large impounded runoff ratio and

potential to affect endangered Southern California steelhead

trout populations (Table 9).

Figure 29

Twitchell Dam and catchment (2,888 km2) on the Cuyama

River, in southern San Luis Obispo and northern Santa

Barbara counties


Twitchell Dam on the Cuyama River. Source: US Bureau of Reclamation.

Table 9

Twitchell Dam on the Cuyama River, San Luis Obispo and Santa Barbara counties

Twitchell Dam


Dam height: 64 m

Reservoir capacity: 290×106 m3


Mean annual inflow: 64.5×106 m3 (empirical), 1,043×106 m3 (model)




Sensitive species potentially below dam: Southern California steelhead

trout, arroyo chub

Low-flows may limit successful passage of steelhead trout through the

Santa Maria to spawning reaches.

CASE STUDIES | 75


Twitchell Dam captures surface runoff from the 2,888-km2

(1,115-mi2) Cuyama River basin. Inflows are intermittent and

highly variable, but yielded an annual average runoff of

64.5×106 m3 from 1967-2010 (City of Santa Maria 2010). The

dam has capacity to capture all inflow in most years (IR = 4.5),

but is operated to release water relatively quickly, such that

the reservoir is often dry in the summer and fall. Releases are

controlled to prevent surface-water reaching the Pacific Ocean,

maximizing potential percolation into the downstream Santa

Maria groundwater basin. Predictions of expected mean flows

by the hydrologic model are unreliable for the Cuyama River

because of the high inter-annual variability of flow patterns.

Model predictions of mean annual flows were about 16 times

greater than observed values. Therefore, deviation of observed

from expected (modeled) flow metrics was not assessed. A

recent instream flow study on the Santa Maria River found

that Twitchell Dam has had no detectable effect on overall

patterns of annual no-flow and peak-flow conditions, but has

altered the timing and frequency of intermediate flows in both

the Cuyama and Santa Maria rivers (Stillwater Sciences and

Kear Groundwater 2012).


The Santa Maria River watershed continues to support

Southern California steelhead trout, listed as endangered

under the federal ESA. Both steelhead trout (anadromous O.

mykiss) and rainbow trout (resident O. mykiss) historically

occurred in the Cuyama River. The extent of historical

steelhead occurence in the Cuyama River watershed above

Twitchell Dam is unknown, but was likely confined to

perennial tributaries of the upper river basin (Stillwater

Sciences and Kear Groundwater 2012). The majority of suitable

habitat for steelhead occurs in the Sisquoc River watershed

(Figure 29), which is smaller than the Cuyama but is not

dammed and has higher flows.

Steelhead spawning in the Cuyama River below Twitchell Dam

has not been documented. Releases from Twitchell, however,

could influence the upstream migration of steelhead through

the Santa Maria River to suitable spawning areas in the


Sisquoc River and perennially flowing tributaries (Stillwater

Sciences and Kear Groundwater 2012). Arroyo chub (Gila

orcuttii, Status 2) may also be present in the Santa Maria

River watershed and could be affected by the operation of

Twitchell Dam.


Twitchell Dam is primarily managed for groundwater recharge

without regard for the downstream flow needs of fish (Twitchell

Management Authority & MNS Engineers 2010). Although the

Cuyama River reach immediately below the dam historically

provided limited suitable habitat for O. mykiss and other

native fishes due to its ephemeral nature, intermittent flows

from the Cuyama improve fish passage opportunities through

the Santa Maria to the Sisquoc River (Stillwater Sciences and

Kear Groundwater 2012). There is evidence that current flow

management at Twitchell Dam has increased the frequency of

flows that trigger upstream steelhead movement. But the flows

are too brief for successful migration (Stillwater Sciences and

Kear Groundwater 2012). Adult steelhead that begin their

upstream migration under favorable flow conditions now run a

greater risk of being stranded.

CASE STUDIES | 77

CASE STUDY 6. LONG VALLEY DAM

Long Valley dam impounds the 226×106 m3 (183,500 acre-feet)

Crowley Lake on the Owens River in southern Mono County

(Figure 30). The 38-m (126-ft) earthen dam was built by the

Los Angeles Department of Water and Power (LADWP) in 1941

to supply the Los Angeles Aqueduct. It is the largest reservoir

in the Los Angeles water system. The dam is also managed for

flood control, hydroelectric power production and recreation.

Figure 30

Long Valley Dam and catchment (994 km2) on the Owen River,

Mono County

Long Valley Dam was included on the list of candidate dams

for its high cumulative impounded runoff ratio and potential to

affect sensitive native species populations, including the

endemic Owens tui chub (Siphatales bicolor snyderi, Status 1)

(Table 10). Owens speckled dace (Rhinichthys osculus, Status


1) appears to have been lost from dam’s HUC12 watershed, but

its current range encompasses tributaries of the Owens River

downstream of the dam.

Long Valley Dam at the head of Owens Gorge impounds the Owens River to form Crowley Lake. Source: S. Volpin.

Table 10

Long Valley Dam on the Owens River, Mono County

Long Valley Dam


Dam height: 38 m



Mean annual inflow: 193×106 m3 (modeled)




Sensitive species potentially below dam: Owens tui chub, Owens speckled

dace

Native species lost from HUC12 watershed below dam: Owens speckled dace

Non-native species, population fragmentation, and habitat degradation may

adversely affect condition native fish.

CASE STUDIES | 79


Long Valley Dam impounds a 994-km2 (383-mi2) catchment of

the Owens Rivers, which is fed by runoff and springs. Inflows

to the dam are augmented by the Mono Craters Tunnel (Figure

27) and the Rock Creek Diversion. A 1998 Water Rights Order

(WR 98-05), allows an annual import through the tunnel of

19.7 ×106 m3 (16,000 acre feet), about a 10% increase in natural

inflows to the reservoir. The impounded runoff ratio of Long

Valley Dam is 1.2, excluding inflows from the tunnel. It is 1.1 if

the augmented flows are included.

No direct downstream discharge is permitted from Long Valley

Dam. All flows purposely bypass a 10-mile long reach

designated as critical habitat for Owens tui chub to prevent

introduction of genetically introgressed tui chub from Crowley

Lake. Flows in the 10-mile reach are maintained by leakage

from the earthen dam and inflows from spring-fed tributaries.

The next 10 river miles are managed for non-native trout and

riparian habitat, through flows from a power plant. Most flows

continue to bypass the Owens River Gorge through three power

plants before being spilling into a small reservoir serving

hydroelectric operations.

Long Valley Dam operations affect Owens River flows for

approximately 90 km (60 mi) to the Tinemaha Dam reservoir,

immediately upstream of Los Angeles Aqueduct intake. Flows

in the affected river reach have truncated peak volumes,

consistently reduced minima, and seasonally delayed high

flows (Hickson and Hecht 1992; Smeltzer and Kondolf 1999).


The Owens River historically supported a diverse assemblage

of native endemic fish species, including the Owens tui chub,

Owens specked dace, Owens pupfish, and Owens sucker

(Catostomus fumeiventris). Human activities, including major

Los Angeles water development projects, have caused the

decline of chub, dace, pupfish and other rare species in the

river basin (U.S. Fish and Wildlife Service 1998). With the

exception of the Owens sucker (Deinstadt and Parmenter 1997),

the basin’s endemic fish populations have become entirely

displaced from the Owens River by introduced predatory fishes.


The Owens tui chub is listed as endangered under both federal

and state ESAs. Once widespread and abundant in the basin,

the fish is currently confined to isolated sites, including a

section of Owens Gorge downstream of Long Valley Dam

designated as critical habitat (50 Federal Register 31593-

31597). Owens specked dace (Status 1) and Owens pupfish

(Status 1) also historically occurred in the river upstream and

downstream of the dam. The historic northern limit of the

pupfish (Status 1) occurred at the approximate site of Pleasant

Valley Dam, 25 river miles below Long Valley Dam. Also,

several alien game fish species have established permanent

populations in Crowley Reservoir and Owens River, including a

productive brown trout fishery.


Long Valley Dam is primarily managed for water supply for

Los Angeles, with secondary power generation objectives.

Flows for fish are not considered in its operations. However,

artificial low flows below the dam appear to sustain an Owens

tui chub population in parts of the designated critical habitat.

Further downstream, hydroelectric diversions have historically

left the river partially or completely dewatered between the

power plants (City of Los Angeles 2010). Los Angeles initiated

a restoration project to improve flows for threatened fish

species between the plants in the downstream half of the gorge

in response to a 1991 state Fish and Game lawsuit over

potential violations of Section 5937 (City of Los Angeles 2010).

The proposed Owens Gorge Restoration Project involves a

modified schedule of flow releases through Owens Gorge that

provides improved base flows for sustaining brown trout and

seasonal pulse flows for riparian recruitment and channel

maintenance. The management of Crowley Lake for water

delivery and flood control is not affected by the project (City of

Los Angeles 2010), and the potential effects of Long Valley

Dam operations on downstream fish has not been evaluated.

Los Angeles is working with U.S. Fish and Wildlife Service,

California Department of Fish and Wildlife, and other state

and federal agencies to approve and implement the Owens

Gorge Restoration Project (LADWP 2013).

CASE STUDIES | 81

CASE STUDY 7. CASITAS DAM

Casitas Dam is on Coyote Creek, approximately 5 km (3 mi)

above its confluence with the Ventura River in Ventura County

(Figure 30). The 102-m (334-ft) earth-fill dam impounds the

313×106 m3 (254,000 acre-feet) Lake Casitas (USBR 2013). The

reservoir captures inflow from the 105-km2 (41 mi2) Coyote

Creek watershed and imported water delivered by canal from

the Robles Diversion Dam on the upper Ventura River (Figure

31). Outlet works at Casitas Dam convey water to the Casitas

Municipal Water District (CMWD) service area. The district

manages the reservoir for irrigation and water supply for

approximately 60,000 people (Latousek 1995).

Figure 31

Casitas Dam and catchment (105 km2) on Coyote Creek, a

tributary to the Ventura River, Ventura County


Casitas Dam was included on the list of candidate dams

because its high impounded runoff index and potential effects

on sensitive populations of Southern California steelhead trout

and arroyo chub (although the chub is not native to the

Ventura River) (Table 11).

Aerial view of Casitas Dam on Coyote Creek, Ventura County. Source: US

Bureau of Reclamation.

Table 11

Casitas Dam on Coyote Creek, Ventura County

Casitas Dam


Dam height: 102 m



Mean annual inflow: 17.9×106 m3 (model, 1970-2000), 11.1×106 m3 (observed,

1928-1955); 16.1×106 m3 is imported from the Ventura River water from

Robles Diversion Dam


IR: 17.5, Cumulative IR: 17.5 (based on modeled Coyote Creek inflow)


Sensitive species potentially below dam: Southern California steelhead trout,

arroyo chub

Lack of perennial flows, low-flows, and degraded habitat conditions adversely

affect condition of downstream native fish populations.

CASE STUDIES | 83


Casitas Dam has the capacity to capture almost 20 times the

natural inflow from Coyote Creek; natural mean annual inflow

to the 313×106 m3 reservoir was predicted to be 17.9×106 m3.

Pre-dam flow records (USGS #11118000, 1928-1955) indicate

that annual flow was slightly lower (11.1×106 m3) than model

predictions. Flows on Coyote Creek are not currently monitored

by USGS. Historic records, however, show natural flows with

strong seasonality and interannual variability. Annual runoff,

which varied historically between 0.06-63×106 m3 per year, was

delivered between January and March, followed by

intermittent flows from June through October (Figure 29).

After Coyote Creek was dammed in the mid-1950s, flows

declined to 2.5×106 m3 per year, on average (1969-1982). Post-

dam monthly flows (1969-1982) were 3-30% of pre-dam flows

(Figure 31). Current water imports from the Robles-Casitas

Canal vary with available runoff, averaging 16.1×106 m3

(13,095 acre feet) per year (Cardno ENTRIX 2012). Flows in

the lower Ventura River are about 50% of their natural,

unimpaired levels due to Casitas Dam and associated facilities

(Cardno ENTRIX 2012). Nearly all outflow from the dam is

exported. As a result, Coyote Creek below the dam is usually

dry (California RWQCB 2002).

Figure 32

Mean monthly flows on Coyote Creek before and after

construction of Casitas Dam, assessed at USGS gage

#11118000



Historically, Coyote Creek was one of the most important

tributaries in the Ventura River watershed for steelhead trout

production (NMFS Service 2003). Construction of Casitas Dam

completely blocked access to spawning and rearing habitat in

Coyote Creek (Becker et al. 2010). The 5-km (3-mi) reach below

the dam does not currently support fish because of low flows

and degraded habitat. Releases from the dam, however, could

allow steelhead to migrate through the lower Ventura River.

Arroyo chub are in the Ventura River near its confluence with

Coyote Creek and could also benefit from improved flows from

Casitas.


Casitas Dam primarily supplies water for irrigation and

municipal needs. There are no required flow releases from

Casitas for fish. The downstream channel is typically

dewatered. Steelhead in the Coyote Creek basin historically

spawned above Casitas Reservoir. Lower Coyote Creek is in

poor condition because of chronic streambank erosion and

insufficient storm-flushing flows (NMFS 2003). Flow releases

from Casitas could potentially benefit steelhead trout

migrating through the lower Ventura River and improve

habitat for other native fish species, including the arroyo chub.

A biological opinion for Robles Diversion Dam sets conditions

for to minimize impacts on steelhead trout in the Ventura

River, but does not address the potential benefits of improving

downstream flows in Coyote Creek below Casitas Dam (NMFS

2003).

CASE STUDIES | 85

CASE STUDY 8. BOLES MEADOW DAM

Boles Meadow Dam is on Boles Creek, a major tributary to

Clear Lake Reservoir in the upper Lost River watershed of

northwest Modoc County (Figures 33). The 2.5-m (8-ft) earthen

dam impounds runoff from the Boles Creek watershed [692

km2 (267 mi2)]. The dam is owned by the U.S. Forest Service

(USFS), which manages the 6×106 m3 (5,000 acre-foot)

reservoir for irrigation and forage production.

Figure 33

Boles Meadow dam and catchment (692 km2) on Boles Creek,

Modoc County

Boles Meadow Dam was included on the list of candidate dams

because of its large cumulative impounded runoff ratio and the

potential presence of several sensitive species downstream of

the dam: the Lost River sucker (Catostomus luxatus, Status 1),

shortnose sucker (Chasmistes breviostris, Status 1), and


Klamath largescale sucker (Catostomus snyderi, Status 2)

(Table 12).

Aerial view of Boles Meadow dam during spring runoff on Boles Creek, Modoc

County. Source: C. Ellsworth.

Table 12

Boles Creek Dam on Boles Creek, Modoc County.

Boles Creek Dam


Dam height: 2.5 m







Sensitive species potentially below dam: Lost River sucker, shortnose

sucker, Klamath largescale sucker, upper Klamath marbled sculpin

Low-flows and habitat degradation may adversely affect condition of fish

downstream. Seasonal impoundment may disrupt migration of sucker.

CASE STUDIES | 87


Boles Creek, a tributary to Clear Lake Reservoir, feeds the

Federal Klamath Irrigation Project (USFS 2012). The creek has

no USGS gages and little published on its hydrology or

potential effects of impoundments. Tate et al. (2007) described

Boles Creekas “intermittent during the summer months

creating large, isolated stream reaches or pools characterized

by bedrock-basalt substrate” underlying the Modoc Plateau.

Base flows naturally remain low through fall and winter and

peak during spring snowmelt, typically between April and

June, based on reports from other streams in the region.

Estimated total annual inflow at Boles Meadow Dam is

16.9×106 m3 (13,700 acre-feet) per year, yielding an IR of 0.4.

The CIR for Boles Meadow is 1.2 when accounting for the total

storage capacity [20.9×106 m3 (16,900 acre-feet)] of all

reservoirs in the catchment (Figure 33). Therefore, reservoirs

in the system have the capacity to capture a significant

proportion of the catchment’s annual runoff, indicating the

potential for significant downstream hydrologic alteration at

Boles Meadow Dam, particularly during spring runoff.


Clear Lake and the upper Lost Creek watershed historically

supported an assemblage of endemic fishes, including several

species of sucker. Both the Lost River and shortnose sucker

were abundant in the Lost River drainage and were the most

important food fish for Native Americans of the Klamath Lakes

region (Gilbert 1898). The Klamath River sucker is uncommon

to the Lost Creek system but may occasionally be present

(Koch and Contreras 1973). The draining and eutrophication of

lakes in the upper Klamath river system, overfishing and

degradation of tributary habitats from cattle grazing and water

diversions have all contributed to the decline of Lost River

sucker and shortnose sucker populations (Moyle 2002). The

Lost River and shortnose sucker are listed as endangered

under federal and state ESAs. Clear Lake populations of Lost

River and shortnose suckers spawn in Boles Creek and other

tributary streams in the spring (Moyle 2002). Fish surveys

from the 1970s found shortnose sucker in Boles Creek (Koch et

al. 1975). The extent to which sucker populations of Clear Lake


currently use Boles Creek for spawning is unknown. Other

native species previously recorded in the creek include the

upper Klamath marbled sculpin (Status 3), blue chub, tui chub,

and speckled dace (Koch et al. 1975).


Boles Meadow Dam is operated to create a seasonal reservoir to

irrigate livestock forage (USFS 2005). There is no evidence that

effects on fish are considered in its operation. The dam

impounds spring flows, thereby reducing flows downstream.

However, moderate to high flows likely spillover the 2.5-m

dam. Such impoundments could be expected to delay re-

watering of the downstream channel in spring and accelerate

the downstream flow recession in summer, potentially

disrupting out-migration of adults and juvenile species from

tributary streams to Clear Lake (S. Reid, personal

communication). Therefore, seasonal timing of reservoir filling

and drawdown at Boles Meadow Dam could be potentially

modified to benefit the condition of fish downstream.

CASE STUDIES | 89

CASE STUDY 9. PINE FLAT DAM

Pine Flat Dam on the Kings River in Fresno County stands

134-m (440-feet) high and stores up to 1,233×106 m3 (1,000,000

acre feet), making it one of the largest reservoirs in California

(Figure 34). The Army Corps of Engineers built the dam in

1954 for flood protection and secondarily for irrigation,

hydroelectric power, and recreation, including a trout fishery.

Pine Flat Dam was included on the list of candidate dams

because of evidence of monthly flow alteration, a high

impounded runoff ratio, the potential harm Kern brook

lamprey (Lampetra hubbsi, Status 2), and the loss of sensitive

fish species from their historic range, including Central Valley

spring-run Chinook salmon (Status 2), Central Valley fall-run

Chinook salmon (Status 2), and Central Valley steelhead

(Status 2) (Table 13).

Figure 34

Pine Flat Dam and catchment (4,000 km2) on the Kings River

in Fresno County. Flows were evaluated at USGS gage

#11221500


Pine Flat Dam on the Kings River, Fresno County. Source: Wikipedia under

GNU Free Documentation License.

Table 13

Pine Flat Dam on the Kings River, Fresno County.

Pine Flat Dam


Dam height: 134 m

Reservoir capacity: 1,233×106 m3


Mean annual inflow: 1,506×106 m3



Observed flows at downstream gage indicate a significant reduction in peak

1-day flows, reduced fall and winter flows, and enhanced summer flows.

Monthly flows follow deviate slightly from expected seasonal patterns (r =

0.79)


Sensitive species potentially below dam: Kern brook lamprey

Species lost from HUC12 watershed affected by dam: Central Valley fall-

run and spring-run Chinook salmon, Central Valley steelhead

CASE STUDIES | 91


The unimpaired annual inflow of the Kings Rivers at Pine Flat

Dam is about 1,506×106 m3 (1,221,000 acre feet) yielding an

impounded runoff ratio of 0.8. There are several other dams in

the 4,000-km2 (1,544-mi2) catchment above Pine Flat, which

have a total storage capacity of about 303×106 m3 (246,000 acre

feet), yielding a cumulative runoff ratio of 1.0. Observed flows

at the USGS gage #11221500 below Pine Flat Dam were

compared with modeled, unimpaired hydrologic metrics.

Observed mean monthly flows were generally lower than

expected values in the late fall and winter (November – March)

and in the spring (April – June) (Figure 35). The most notable

deviation from expected patterns was in the summer and early

fall (July – October), when observed monthly flows were

estimated to be 1.5-2 times greater than expected values.

Overall, there was moderate deviation from expected seasonal

flow patterns (r = 0.79). Observed maximum 1-day flows were

about 50% of expected values, reflecting the dams flood-control

operations.

Figure 35

Expected (E, modeled) and observed mean monthly flows below

Pine Flat Dam on the Kings River



Spring- and fall-run Chinook salmon historically occurred at

least periodically in the Kings River, when floodwaters in the

Tulare Lake Basin spilled into the San Joaquin River system,

providing access for fish to the Kings River. Salmon would

ascend the Kings River and spawn up to the mouth of the

North Fork Kings River (Yoshiyama et al. 2001). Water

diversions for San Joaquin Valley farmers resulted in the

extirpation of salmon runs in the Kings and upper San Joaquin

rivers by the mid-20th century (Yoshiyama et al. 2001). The

Kern brook lamprey (Lampetra hubbsi) is an endemic species

to the San Joaquin River Basin. Relatively little is known

about the life history and historic distribution of the lamprey

(Moyle 2002). Known populations are isolated and include a

Kings River population above and below Pine Flat Dam. The

risk of local extirpation is high because of the lamprey’s

fragmented distribution and occurrence below dams that are

operated with limited regard to their flow needs. The lower

river also supports Sacramento pikeminnow, Sacramento

sucker, and two species of sculpin, but the population status of

these species in the river is not known.


The Army Corps operates Pine Flat Dam to reduce flood flows

in the spring, and enhance flows in the summer for agricultural

irrigation. In 1964, CDFW entered an agreement with the Kern

River Water Association (KRWA) and Kern River Conservation

District (KRCD) to secure minimum flow releases below Pine

Flat Dam, primarily to restore a trout fishery. In the 1990s,

modifications to the Pine Flat Dam and downstream power

plant were made to better control the temperature of outflows

to the river. These changes were followed by the development

of the Kings River Fisheries Management Program, which

established new agreements between CDFW and facility

operators at Pine Flat and upstream dams to improve the

quantity and quality (i.e., temperature) of downstream flow

releases for trout (KRCD and KRWA 2003).

CASE STUDIES | 93

CASE STUDY 10. DWINNELL DAM

Dwinnell Dam is on the Shasta River in Siskiyou County

(Figure 36). The dam impounds the 62×106 m3 (50,000 acre-

feet) Dwinnell Reservoir, also known as Lake Shastina. The

reservoir was constructed in the late 1920s as a water supply

project for the Montague Water Conservation District (MWCD).

The reservoir is fed by inflows from the Shasta River and a

diversion from Parks Creek, about 2 km (1.2 mi) upstream

from the reservoir. MWCD owns Dwinnell Dam and operates

it primarily to irrigate pasture.

Figure 36

Dwinnell Dam and catchment (142 km2) on the Shasta River,

Siskiyou County


Dwinnell Dam was included on the list of candidate dams

because of its high impounded runoff index and its potential

effects on sensitive species populations, including ESA-listed

Southern Oregon/Northern California coast coho salmon

(Status 1), Upper Klamath-Trinity fall run Chinook salmon

(Status 2) and Klamath Mountain Province winter steelhead

(Status 3) (Table 14).

Dwinnell Dam on the Shasta River, Siskiyou County. Source: S. Harding/Klamath Riverkeeper.

Table 14

Dwinnell Dam on the Shasta River, Siskiyou County.

Pine Flat Dam


Dam height: 29 m

Reservoir capacity: 61.7×106 m3 (50,000 acre feet)

Catchment area: 142 km2 (55 mi2)

Mean annual inflow: 74×106 m3 (empirical); 188×106 m3 (model)


IR: 0.81, Cumulative IR: 0.81 (based on empirical inflow estimates)


Sensitive species potentially below dam: Southern Oregon/Northern

California coho salmon and Upper Klamath-Trinity fall run Chinook salmon

CASE STUDIES | 95


Dwinnell dam impounds the 370 km2 (143 mi2) upper Shasta

River watershed. The reservoir receives annual inflows of

about 74×106 m3 (60,000 acre feet) per year, including imported

water from an upstream diversion on Parker Creek (Vignola

and Deas 2005). This is significantly lower than model

predictions of 188×106 m3 per year. Based on the lower annual

inflow estimate, the dam has an IR value of 0.81. There are no

large dams present in the upstream catchment, so the

cumulative IR is essentially the same as the IR.

Outflows from the reservoir include controlled and uncontrolled

releases to the Shasta River and controlled releases to the

MWCD irrigation canal (Figure 36). Observed monthly flows

were not compared with expected values because of the poor

predictive performance of the model for the Shasta River.

Previous studies, however, have documented significant

reductions in Shasta River flows relative to simulated,

unimpaired conditions. For example, Null et al. (2010) reported

that current flow releases below Dwinnell Dam are limited to

0.05 m3/s because of leakage, with summer releases up to 0.25

m3/s to fulfill downstream water rights, compared with

simulated unimpaired baseflows of 1-4 m3/s. Null et al. (2010)

also reported that the dam captured all inflows from the upper

Shasta River and Parks Creek in most years and, as a result,

downstream flows showed only modest peaks from storm

runoff.


The Shasta River historically supported healthy populations of

Chinook salmon, coho salmon, and steelhead trout. It was one

of the most productive tributaries in the Klamath River Basin.

Dwinnell dam blocked salmon and steelhead passage to

approximately 22 percent of historical spawning and rearing

habitat in the Shasta River Basin (CDFW 2012). Declining

annual returns of salmon to the Shasta have tracked range-

wide population declines over the past several decades (Moyle

2002). Below the dam, habitat conditions for salmon and

steelhead have been degraded by low-flows and high water

temperatures (Null et al. 2010), although these conditions are

only partially attributable to Dwinnell Dam. Other native


species potentially present in the Shasta below Dwinnell Dam

include Pacific lamprey, Klamath River lamprey, Klamath

River speckled dace, and Klamath small-scale sucker (Deas et

al. 2004).


Most of the water impounded by Dwinnell Dam is released to

the MWCD irrigation canal, resulting in year-round flow

impairment to the Shasta River. During the irrigation season,

flows released from the dam into the Shasta River are typically

limited to 0.25 m3/s to fulfill downstream water rights (Null et

al. 2010). However, changes in dam operations are likely to

occur in the future, following recommendations of a recent

instream flow assessment on the Shasta River (McBain and

Trush 2013). The recommendations are intended keep fish in

good condition, as Fish and Game Code 5937 requires. They

include increased summer flows to maintain suitable water

temperatures and high-pulse spring releases to promote

salmon smolt outmigration.

CASE STUDIES | 97

CASE STUDY FINDINGS

These case studies provide preliminary, site-specific

investigations of dam operations and their potential effects on

downstream fish. Indicators of hydrologic alteration and fish

population impairment used in the systematic evaluation of

dams generally corresponded with site-specific reports of

environmental conditions and downstream effects of the case

study dams.

All of the dams were confirmed to have evidence of downstream

impacts to sensitive fish populations. For dams with reliable

downstream flow gages, there was direct evidence of hydrologic

alteration. For other dams, qualitative descriptions of

hydrologic impacts from technical reports and interviews

indicated that flows below dams also deviated in some way

from expected, unimpaired conditions. The case studies found

some limitations in the hydrologic model used to predict annual

flows, particularly for intermittent streams in arid regions

(e.g., Cuyama Creek and Conn Creek). However, locally derived

estimates of annual flows were generally available in published

reports.

Several of the case study dams are subject to some form of

environmental flow requirements, for example, the biological

opinion for Stony Creek, the Joint Settlement Agreement for

the Mokelumne River, and the state water board order for

Lagunitas Cree. Also, Section 5937 has been considered in

identifying flow needs for fish below Long Valley Dam, Peters

Dam and Dwinnell Dam. For Peters Dam, the summer flow

releases are apparently responsible for maintaining Lagunitas

Creek as an important refuge for threatened coho salmon and

other cold-water species.

Other dams appear to have limited or no protections of

downstream flows for sustaining fish, including Conn Creek,

Boles Meadow, Casitas, Twitchell and Dwinnell. Current

efforts to assess environmental flow needs in the Santa Maria

and Shasta River suggest that the management of flow releases

for fish below Twitchell and Dwinnell may be improved.

Operations of the case study dams were influenced by a diverse

and complex suite of legal and institutional factors, involving


local water districts, multiple state and federal agencies and

private parties. The studies also showed that dam operations

and their consequent effects on downstream flows were often

affected by other dams and diversions located up- and

downstream. Inflows and operations of the Woodbridge

Diversion Dam, for example, are completely dependent on

management of major upstream dams under separate

ownership. The highly integrated nature of water management

projects suggests that modifications to dam operations to

provide Section 5937 flows would require working not only with

the owner/operators of the dam, but also with operators of

other water works in the river basin.

For the case study dams, observed downstream flow alteration

was generally coupled with significant downstream habitat

alteration. The degradation of habitat was associated with

direct effects of the dam (e.g., downstream channel incision

from the loss of sediment inputs) and indirect effects (e.g., land

use development along the stream corridor facilitated by the

reduction in flood risk). The poor habitat conditions below

many dams suggest that improving flows for fish may also

require habitat restoration to maintain fish in good condition.

In addition, the presence of non-native species may preclude

the recovery of native fish populations (Moyle and Mount

2007), although the success of a managed environmental flow

regime to suppress alien fishes is a hopeful sign (Kiernan et al.

2012). Therefore, outcomes of restoring Section 5937 flows are

likely to be influenced by many physical and ecological factors

that warrant careful consideration.

Overall, the case studies showed that each dam has a unique

set of management constraints, jurisdictional issues, and

environmental factors that must be addressed in the context of

Section 5937. This is probably true of all dams. We recommend

that site-specific analyses presented in the case studies be done

for every high-priority dam identified in this study.

99

REFERENCES

Annear, T., I. Chisholm, H. Beecher, A. Locke, P. Aarrestad, C. Coomer, C. Estes, J. Hunt,

R. Jacobson, G. Jobsis, J. Kauffman, J. Marshall, K. Mayes, G. Smith, R. Wentworth & C.

Stalnaker, 2004. Instream Flows for Riverine Resource Stewardship, Revised Edition.

Instream Flow Council, Cheyenne, Wyoming.

Arthington, A. H., 2012. Environmental Flows: Saving Rivers in the Third Millenium.

University of California Press, Berkeley, California.

Batalla, R. J., C. M. Gómez & G. M. Kondolf, 2004. Reservoir-induced hydrological changes

in the Ebro River basin (NE Spain). Journal of Hydrology 290(1-2):117-136.

Becker, G. S., K. M. Smetak & D. A. Asbury, 2010. Southern Steelhead Resources

Evaluation: Identifying Promising Locations for Steelhead Restoration in Watersheds

South of the Golden Gate. Center for Ecosystem Management and Restoration, Oakland,

California,

Börk, K. S., J. F. Krovoza, J. V. Katz & P. B. Moyle, 2012. The rebirth of Cal. Fish & Game

Code 5937: water for fish. UC Davis Law Review 45:809-913.

Brown L. R. & T. Ford. 2002. Effects of flow on the fish communities of a regulated

California river: implications for managing native fishes. River Research and Applications

18:331-342.

Brown, L. R. & M. L. Bauer, 2010. Effects of hydrologic infrastructure on flow regimes of

California's Central Valley rivers: Implications for fish populations. River Research and

Applications 26(6):751-765.

Bunn, S. E. & A. H. Arthington, 2002. Basic principles and ecological consequences of

altered flow regimes for aquatic biodiversity. Environmental Management 30(4):492-507.

Bureau of Reclamation (USBR), 2013. Ventura River Project. Available at

http://www.usbr.gov/projects/Project.jsp?proj_Name=Ventura%20River%20Project, accessed

February 9, 2013 2013.

California Department of Fish and Wildlife (CDFW), 2012. Passage Assessment Database.

Available at https://nrm.dfg.ca.gov/PAD/Default.aspx, accessed April 20, 2012.

California Department of Water Resources (DWR), 2010. California Jurisdictional Dams.

Available at: http://www.water.ca.gov/damsafety/damlisting/index.cfm, accessed March 2,

2012.

Cardno ENTRIX, 2012. Ventura River Watershed Protection Plan Report Prepared for

Ventura Couty Watershed Protection District. Santa Barbara, California.

100

Carlisle, D., J. Falcone, D. M. Wolock, M. R. Meador & R. H. Norris, 2010a. Predicting the

natural flow regime: Models for assessing hydrological alteration in streams. River

Research and Applications 26(2):118-136.

Carlisle, D., D. M. Wolock & M. R. Meador, 2010b. Alteration of streamflow magnitudes

and potential ecological consequences: A multiregional assessment. Frontiers in Ecology

and the Environment 9:264-270.

Cayan, D. R., K. T. Redmond & L. G. Riddle, 1999. ENSO and hydrologic extremes in the

Western United States. Journal of Climate 12:2881-2893.

City of Los Angeles, 2010. Initial Study for Owens River Gorge Restoration Project. Los

Angeles, California.

City of Santa Maria, 2010. Santa Maria Valley Management Area 2010 Annual Report of

Hydrologic Conditions, Water Requirements, Supplies and Disposition. Santa Maria,

California.

Clavero, M., F. Blanco-Garrido & J. Prenda, 2004. Fish fauna in Iberian Mediterranean

river basins: Biodiversity, introduced species and damming impacts. Aquatic Conservation

14:575-585.

Danskin, W. R., 1998. Evaluation of the Hydrologic System and Selected Water-

Management Alternatives in the Owens Valley, California. US Geological Survey Water-

Supply Paper 2370.

Deas, M., P. B. Moyle, J. Mount, J. R. Lund, C. L. Lowney & S. Tanaka, 2004. Priority

Actions for Restoration of the Shasta River – Technical Report. Prepared for the Nature

Conservancy.

Deinstadt, J. & S. Parmenter, 1997. Lower Owens River Wild Trout Management Plan.

California Department of Fish and Game.

Dudgeon, D., A. H. Arthington, M. O. Gessner, Z. I. Kawabata, D. J. Knowler, C. Leveque,

R. J. Naiman, A. H. Prieur-Richard, D. Soto, M. L. J. Stiassny & C. A. Sullivan, 2006.

Freshwater biodiversity: Importance, threats, status and conservation challenges.

Biological Reviews 81(2):163-182.

East Bay Municipal Utility District, California Department of Fish and Game, U.S. Fish

and Wildlife Service, 2008. Lower Mokelumne River Project Joint Settlement Agreement

Ten-Year Review.

Eng, K., D. M. Carlisle, D. M. Wolock & J. A. Falcone, 2012. Predicting the likelihood of

altered streamflows at ungauged rivers across the coterminuous United States. River

Research and Applications [Early View].

101

Frank, R. M., 2012. The Public Trust Doctrine: assessing its recent past and charting its

future. UC Davis Law Review 45:665-692.

Gasith, A. & V. H. Resh, 1999. Streams in Mediterranean climate regions: abiotic

influences and biotic responses to predictable seasonal events. Annual Review of Ecology

and Systematics 30:51-81.

Gehrke, P. C & J. H. Harris, 2001. Regional-scale effects of flow regulation on lowland

riverine fish communities in New South Wales, Australia. Regulated Rivers: Research &

Management 17: 369–391.

Gilbert, G. H., 1898. The fishes of the Klamath Basin. Bulletin US Fish Communication

17:1-13.

Gillilan, D. M. & T. C. Brown, 1997. Instream Flow Protection: Seeking a Balance in

Western Water Use. Island Press, Washington DC.

Goslin, M., 2005. Creating a comprehensive dam dataset for assessing anadromous fish

passage in California. NOAA Technical Memorandum NOAA-TM-NMFS-SWFSC-376.

Santa Cruz, California.

Graf, W. L., 2006. Downstream hydrologic and geomorphic effects of large dams on

American rivers. Geomorphology 79(3-4):336-360.

Grantham, T., R. Figueroa & N. Prat, 2012. Water management in mediterranean river

basins: a comparison of management frameworks, physical impacts, and ecological

responses. Hydrobiologia [Online First]:1-32.

Hickson, T., B. Hecht & E. Larsen, 1992. Changes over time in geomorphic condition,

sediment transport, and riparian cover in the Owens River below Pleasant Valley Dam,

Inyo County, California. Prepared for Jones & Stokes Associates by Balance Hydrologics,

Inc., Berkeley.

H.T. Harvey & Associates, 2007. Stony Creek Watershed Assessment, Vol. 2. Existing

Conditions Report. Prepared for the Glenn County Resource Conservation District.

Horizon Systems, 2012. NHDPlus, version 2. Available at: http://www.horizon-

systems.com/nhdplus/, accessed January 12, 2012.

Katz, J., P. Moyle, R. Quiñones, J. Israel & S. Purdy, 2012. Impending extinction of salmon,

steelhead, and trout (Salmonidae) in California. Environmental Biology of Fishes:1-18.

Kern River Conservation District & Kern River Water Assoiation (KRCD & KRWA), 2003.

The Kings River Handbook, 4th edition. Fresno, California.

102

Kiernan, J., P. B. Moyle & P. K. Crain, 2012. Restoring native fish assemblages to a

regulated California stream using the natural flow regime concept. Ecological Applications

22(5):1472-1482.

Koch, D. L. & G. P. Contreras, 1973. Preliminary survey of fishes of the Lost River System

including Lower Klamath Lake and Klamath Strait Drain with special reference to the

shortnose (Chasmistes brevirostris) and Lost River (Catostomus luxatus) suckers. Center

for Water Resrouces Resarch, Desert Research Institute, University of Nevada System,

Reno, Nevada.

Koch, D. L., J. J. Cooper, G. P. Contreras & V. King, 1975. Survey of fishes of the Clear

Lake Reservoir drainage, Project Report No 37. Center for Water Resources Research,

Desert Research Institute, University of Nevada System, Reno, Nevada.

Kondolf, G. M. & R. J. Batalla, 2005. Hydrological effects of dams and water diversions on

rivers of Mediterranean-climate regions: examples from California. In Garcia, C. & R. J.

Batalla (eds) Catchment Dynamics and River Processes: Mediterranean and Other Climate

Regions. Elsevier, 197-211.

Kondolf, G. M., 1997. Hungry water: Effects of dams and gravel mining on river channels.

Environmental Management 21(4):533-551.

Kondolf, G. M., K. Podolak & T. Grantham, 2012. Restoring mediterranean-climate rivers.

Hydrobiologia [Online First].

Latousek, T. A., 1995. The Ventura River Project. Bureau of Reclamation.

Lindley, S. T., R. S. Schick, A. Agrawal, M. Goslin, T. E. Pearson, E. More, J. J. Anderson,

B. May, S. Greene, C. Hanson, A. Low, D. McEwan, R. B. MacFarlane, C. Swanson & J. G.

Williams, 2006. Historical Population Structure of Central Valley Steelhead and its

Alteration by Dams. San Francisco Estuary & Watershed Science 4:1-19.

Los Angeles Department of Water and Power, 2013. Owens River Gorge Watershed, Gorge

Rewatering Project. Available at:

http://wsoweb.ladwp.com/Aqueduct/WatershedMgmtWeb/gorge.htm, accessed February 7,

2013.

Lytle, D. A. & N. L. Poff, 2004. Adaptation to natural flow regimes. Trends in Ecology &

Evolution 19(2):94-100.

Magdaleno, F. & A. J. Fernández, 2011. Hydromorphological alteration of a large

mediterranean river: Relative role of high and low flows on the evolution of riparian forests

and channel morphology. River Research and Applications 27(3):374-387.

Marchetti, M. P. & P. B. Moyle, 2001. Effects of flow regime on fish assemblages in a

regulated California stream. Ecological Applications 11(2):530-539.

103

Marin Municipal Water District (MMWD), 2011. Lagunitas Creek Stewardship Plan –

Final. June 2011.

McBain and Trush, 2013. Shasta River Big Springs Complex Interim Instream Flow Needs

Assessment. Prepared by McBain and Trush, Inc., Department of Environmental

Resources Engineering, and Humboldt State University for the Ocean Protection Council

and California Department of Fish and Wildlife.

Rinne, J. N., R. M. Hughes, & B. Calamusso (eds), 2005. Historical changes in large river

fish assemblages of the Americas. American Fisheries Society Symposium 45, Bethesda,

Maryland.

Merz, J. E. & J. D. Setka, 2004. Evaluation of a spawning habitat enhancement site for

Chinook salmon in a regulated California river. North American Journal of Fisheries

Management 24(2):397-407.

Merz, J. E. & M. S. Saldate, 2004. Lower Mokelumne River Fish Community Survey, 1

January 1997 through 30 June 2004.

Minear, T., 2010. The Downstream Geomorphic Effects of Dams: A Comprehensive and

Comparative Approach. Dissertation, University of California, Berkeley.

Montgomery, D. R., E. M. Beamer, G. R. Pess & T. P. Quinn, 1999. Channel type and

salmonid spawning distribution and abundance. Canadian Journal of Fisheries and Aquatic

Sciences 56(3):377-387.

Moyle, P. B. & J. F. Mount, 2007. Homogenous rivers, homogenous faunas. Proceedings of

the National Academy of Sciences 104(14):5711-5712.

Moyle, P. B., 2002. Inland Fishes of California, Rev. and expanded edn. University of

California Press, Berkeley, California.

Moyle, P. B., J. D. Kiernan, P. K. Crain & R. Quiñones, 2012. Projected effects of future

climates on freshwater fishes of California. California Energy Commission Report, CEC-

500-2012-028.

Moyle, P. B., J. V. E. Katz & R. M. Quiñones, 2011. Rapid decline of California's native

inland fishes: A status assessment. Biological Conservation 144(10):2414-2423.

Moyle, P. B., M. P. Marchetti, J. Baldridge & T. L. Taylor, 1998. Fish health and diversity:

Justifying flows for a California stream. Fisheries 23(7):6-15.

Murphy, G. I. 1949. The 1947 and 1948 Fishery at Conn Valley Reservoir, Napa County.

California Division of Fish and Game, Administrative Report 49-1.

104

Napa County Resource Conservation District, 2005. Central Napa River Watershed Project:

Salmon Habitat Form and Function. Prepared for California Department of Fish and

Game, Napa, California.

City of Napa, 2006. Urban Water Management Plan, 2005 Update. Public Works

Department, Water Division, Napa, California.

National Marine Fisheries Service (NMFS), 2002. Biological Opinion for the Lower

Mokelumne River Restoration Program: Fish Passage Improvements on the Woodbridge

Dam and WID Diversion Canals.

National Marine Fisheries Service (NMFS), 2003. Biological Opinion for the proposed

Robles Diversion Fish Passage Facility Project.

National Marine Fisheries Service (NMFS), 2008. Final Biological Opinion for lower Stony

Creek.

Nilsson, C., C. A. Reidy, M. Dynesius & C. Revenga, 2005. Fragmentation and flow

regulation of the world's large river systems. Science 308(5720):405-408.

Null, S. E., M. L. Deas & J. R. Lund, 2010. Flow and water temperature simulation for

habitat restoration in the Shasta River, California. River Research and Applications

26(6):663-681.

Null, S.E., J.H. Viers, M.L. Deas, S.K. Tanaka & J.F. Mount, 2013. Stream temperature

sensitivity to climate warming in California’s Sierra Nevada: Impacts to coldwater habitat.

Climatic Change, 116(1):149-170.

Olden, J. D. & N. L. Poff, 2003. Redundancy and the choice of hydrologic indices for

characterizing streamflow regimes. River Research and Applications 19(2):101-121.

Opperman, J. J., R. Luster, B. A. McKenney, M. Roberts & A. W. Meadows, 2010.

Ecologically Functional Floodplains: Connectivity, Flow Regime, and Scale. J Am Water

Resour Assoc 46(2):211-226.

Pasternack, G. B., C. L. Wang & J. E. Merz, 2004. Application of a 2D hydrodynamic model

to design of reach-scale spawning gravel replenishment on the Mokelumne River,

California. River Research and Applications 20(2):205-225.

Poff, N. L. & J. K. H. Zimmerman, 2010. Ecological responses to altered flow regimes: a

literature review to inform the science and management of environmental flows.

Freshwater Biology 55(1):194-205.

Poff, N. L., J. D. Allan, M. B. Bain, J. R. Karr, K. L. Prestegaard, B. D. Richter, R. E.

Sparks & J. C. Stromberg, 1997. The natural flow regime: A paradigm for river

conservation and restoration. Bioscience 47(11):769-784.

105

Richter, B. D., M. M. Davis, C. Apse & C. Konrad, 2011. A presumptive standard for

environmental flow protection. River Research and Applications 28(8):1312-1321.

Singer, M. B., 2007. The influence of major dams on hydrology through the drainage

network of the Sacramento River basin, California. River Research and Applications

23(1):55-72.

Smeltzer, M. W. & G. M. Kondolf, 1999. Historical geomorphic and hydrologic analysis of

the Owens River Gorge. Prepared for the Department of Fish and Game, Bishop, California.

State Water Resources Control Board (SWRCB), 2002. State of the Watershed - report on

surface water quality, the Ventura River watershed. California Regional Water Quality

Control Board, Los Angeles Region.

State Water Resources Control Board (SWRCB), 2012. eWRIMS (Electronic Water Rights

Information Management System). Available at http://www.waterboards.ca.gov/ewrims/,

accessed April 15, 2012.

Stillwater Sciences. 2008. Lagunitas limiting factors analysis: liming factors for coho

salmon and steelhead, Final report. Prepared by Stillwater Sciences, Berkeley, California

for Marin Resource Conservation District, Point Reyes Station, California.

Stillwater Sciences & Kear Groundwater. 2012. Santa Maria River Instream Flow Study:

flow recommendations for steelhead passage, Final Report. Prepared by Stillwater Sciences,

Santa Barbara, California; and Kear Groundwater, Santa Barbara, California for California

Ocean Protection Council, Oakland, California; and California Department of Fish and

Game, Sacramento, California.

Tate, K., D. Lancaster & D. Lile, 2007. Assessment of thermal stratification within stream

pools as a mechanism to provide refugia for native trout in hot, arid rangelands.

Environmental Monitoring and Assessment 124(1):289-300.

Twitchell Management Authority & MNS Engineers, Inc., 2010. Twitchell Project Manual.

United States Army Corps of Engineers (USACE), 2010. National Inventory of Dams.

Unites States Forest Service (USFS), 1998. Owens Basin Wetland and Aquatic Species

Recovery Plan, Inyo and Mono Counties, California. Portland, Oregon.

Unites States Forest Service (USFS), 2005. Modoc County Resource Advisory Committee

Meeting Minutes, 6 June 2005. Available at:

https://fsplaces.fs.fed.us/fsfiles/unit/r4/payments_to_states.nsf/Web_Agendas/A12DD72CEF

FB503B88257018005AF77F?OpenDocument, accessed February 2, 2012.

106

Unites States Forest Service (USFS), 2012. Modoc National Forest, Chapter IV Water.

Available at: http://www.fs.usda.gov/detail/modoc/learning/history-culture/?cid=

stelprdb5310681, accessed October 22, 2012 2012.

Viers, J. H., J. Katz, R. Peek, N. Santos & P. B. Moyle, 2012. PISCES - fish distribution

tracking, modelling, and analysis. University of California Davis, Center for Watershed

Sciences, Davis, California. Available at http://pisces.ucdavis.edu.

Vignola, E. & M. Deas, 2005. Lake Shastina limnology. Watercourse Engineering, Inc.,

Davis, California.

Yoshiyama, R. M., E. R. Gerstung, F. W. Fisher & P. B. Moyle, 2001. Historic and present

distribution of chinook salmon in the Central Valley drainage of California. In Brown, R. L.

(ed) Fish Bulletin 179 Contributions to the biology of Central Valley salmonids. vol 1.

California Department of Fish and Game, Sacramento, 71-76.

107

APPENDIX A

SENSITIVE NATIVE FISH SPECIES LIST

California native fish species with sensitive (at risk, vulnerable, or near-threatened)

population status, per Moyle et al. (2011).

Common Name Scientific Name Conservation Status

Goose Lake lamprey Entosphenus tridentata 2-Vulnerable

Kern brook lamprey Lampetra hubbsi 2-Vulnerable

Northern green sturgeon Acipenser medirostris 2-Vulnerable

Southern green sturgeon Acipenser medirostris 1-Endangered

White sturgeon Acipenser transmontanus 2-Vulnerable

Thicktail chub Siphatales crassicauda 0-Extinct

Cow Head tui chub Siphatales thalassinus vaccaceps 2-Vulnerable

High Rock Springs tui chub Siphatales bicolor subspecies 0-Extinct

Lahontan lake tui chub Siphatales bicolor pectinifer 2-Vulnerable

Owens tui chub Siphatales bicolor snyderi 1-Endangered

Mojave tui chub Siphatales mohavensis 1-Endangered

Bonytail Gila elegans 0-Extinct

Arroyo chub Gila orcutti 2-Vulnerable

Clear Lake hitch Lavinia exilicauda chi 1-Endangered

Monterey hitch Lavinia exilicauda harengeus 2-Vulnerable

Red Hills roach Lavinia symmetricus subspecies 2-Vulnerable

Northern (Pit) roach Lavinia mitrulus 2-Vulnerable

Sacramento splittail Pogonichthys macrolepidotus 2-Vulnerable

Clear Lake splittail Pogonichthys ciscoides 0-Extinct

Colorado pikeminnow Ptychocheilus lucius 0-Extinct

Owens speckled dace Rhinichthys osculus subspecies 1-Endangered

Long Valley speckled dace Rhinichthys osculus subspecies 1-Endangered

Amargosa Canyon speckled

dace Rhinichthys osculus nevadensis 1-Endangered

Santa Ana speckled dace Rhinichthys osculus subspecies 1-Endangered

Goose Lake sucker Catostomus occidentalis lacusanserinus

2-Vulnerable

Modoc sucker Catostomus microps 1-Endangered

Klamath largescale sucker Catostomus snyderi 2-Vulnerable

Lost River sucker Catostomus luxatus 1-Endangered

Santa Ana sucker Catostomus santaanae 1-Endangered

Flannelmouth sucker Catostomus latipinnis 1-Endangered

Shortnose sucker Chasmistes brevirostris 2-Vulnerable

Razorback sucker Xyrauchen texanus 1-Endangered

108

Eulachon Thaleichthys pacificus 1-Endangered

Longfin smelt Spirinchus thaleichthys 2-Vulnerable

Delta smelt Hypomesus pacificus 1-Endangered

Bull trout Salvelinus confluentus 0-Extinct

Upper Klamath-Trinity fall

Chinook salmon Oncorhynchus tshawytscha 2-Vulnerable

Upper Klamath-Trinity

spring Chinook salmon Oncorhynchus tshawytscha 1-Endangered

California Coast fall Chinook

salmon Oncorhynchus tshawytscha 2-Vulnerable

Central Valley winter


Central Valley spring


Central Valley late fall

Chinook salmon Oncorhynchus tshawytscha 1-Endangered

Central Valley fall Chinook

salmon Oncorhynchus tshawytscha 2-Vulnerable

Central Coast coho salmon Oncorhynchus kisutch 1-Endangered

Southern Oregon Northern

California coast coho salmon Oncorhynchus kisutch 1-Endangered

Pink salmon Oncorhynchus gorbuscha 1-Endangered

Chum salmon Oncorhynchus keta 1-Endangered

Northern California coast

summer steelhead Oncorhynchus mykiss 1-Endangered

Klamath Mountains Province

summer steelhead Oncorhynchus mykiss 1-Endangered

Central California coast

winter steelhead Oncorhynchus mykiss 2-Vulnerable

Central Valley steelhead Oncorhynchus mykiss 2-Vulnerable

South Central California

coast steelhead Oncorhynchus mykiss 2-Vulnerable

Southern California

steelhead Oncorhynchus mykiss 1-Endangered

McCloud River redband trout Oncorhynchus mykiss stonei 1-Endangered

Eagle Lake rainbow trout Oncorhynchus mykiss aquilarum 2-Vulnerable

Kern River rainbow trout Oncorhynchus mykiss gilberti 1-Endangered

California golden trout Oncorhynchus mykiss aguabonita 2-Vulnerable

Little Kern golden trout Oncorhynchus mykiss whitei 2-Vulnerable

Paiute cutthroat trout Oncorhynchus clarki seleneris 1-Endangered

Lahontan cutthroat trout Oncorhynchus clarki henshawi 2-Vulnerable

Desert pupfish Cyprinodon macularius 1-Endangered

Owens pupfish Cyprinodon radiosus 1-Endangered

Saratoga Springs pupfish Cyprinodon nevadensis nevadensis 2-Vulnerable

Amargosa River pupfish Cyprinodon nevadensis amargosae 2-Vulnerable

Tecopa pupfish Cyprinodon nevadensis calidae 0-Extinct

Shoshone pupfish Cyprinodon nevadensis shoshone 1-Endangered

109

Salt Creek pupfish Cyprinodon salinus salinus 2-Vulnerable

Cottonball Marsh pupfish Cyprinodon salinus milleri 2-Vulnerable

Bigeye marbled sculpin Cottus klamathensis macrops 2-Vulnerable

Unarmored threespine

stickleback Gasterosteus aculeatus williamsoni 1-Endangered

Shay Creek stickleback Gasterosteus aculeatus subspecies 1-Endangered

Sacramento perch Archoplites interruptus 1-Endangered

Tidewater goby Eucyclogobius newberryi 2-Vulnerable

110

APPENDIX B

LIST OF DAMS EVALUATED

NID Dam Name County River

CA00002 Mendocino 3 Upper Mendocino Mill Creek

CA00004 Marie, Lake Napa Trib Tulucay Creek

CA00005 Henderson Amador Jackass Creek

CA00011 Rector Creek Napa Rector Creek

CA00015 Lower Buck Lake Tuolumne Buck Meadow Creek

CA00016 Bigelow Lake Tuolumne East Fork Cherry Creek

CA00019 Schmidell Lake El Dorado Trib Rubicon River

CA00020 Round Lake El Dorado Upper Truckee River

CA00026 McClure Lake Madera Trib East Fork Granite Creek

CA00027 Madera Lake Madera Fresno River

CA00029 Whale Rock San Luis Obispo Old Creek

CA00030 Benbow Humboldt South Fork Eel River

CA00031 Eureka Plumas Eureka Creek

CA00032 Frenchman Plumas Little Last Chance Creek

CA00035 Oroville Butte Feather River

CA00036 Thermalito Diversion Butte Feather River

CA00037 Antelope Plumas Indian Creek

CA00038 Lower Sardine Lake Sierra Sardine Creek

CA00039 Grizzly Valley Plumas Big Grizzly Creek

CA00043 Del Valle Alameda Arroyo Valley

CA00044 Castaic Los Angeles Castaic Creek

CA00049 Cedar Springs San Bernardino West Fork Mojave River

CA00052 Pyramid Los Angeles Piru Creek

CA00067 Chatsworth Los Angeles Trib Los Angeles River

CA00068 Dry Canyon Los Angeles Dry Canyon Creek

CA00072 Big Pine Creek Inyo Big Pine Creek

CA00076 Lower San Fernando

(Lower Van Norman) Los Angeles San Fernando Creek

CA00084 Tinemaha Inyo Owens River

CA00088 Bouquet Canyon Los Angeles Bouquet Creek

CA00089 Grant Lake Mono Rush Creek

CA00090 Long Valley Mono Owens River

CA00091 Walker Lake Mono Walker Creek

CA00092 Sardine Lake Mono Walker Creek

111

CA00098 Pleasant Valley Inyo Owens River

CA00102 Milliken Napa Milliken Creek

CA00104 Conn Creek Napa Conn Creek

CA00106 Barrett San Diego Cottonwood Creek

CA00108 Hodges, Lake San Diego San Dieguito River

CA00109 Savage San Diego Otay River

CA00110 Morena San Diego Cottonwood Creek

CA00111 El Capitan San Diego San Diego River

CA00112 Upper Otay San Diego Proctor Val Creek

CA00113 San Vicente San Diego San Vicente Creek

CA00114 Sutherland San Diego Santa Ysabel Creek

CA00120 Early Intake Tuolumne Tuolumne River

CA00121 Lake Eleanor Tuolumne Eleanor Creek

CA00122 Moccasin Lower Tuolumne Moccasin Creek

CA00123 O'Shaughnessy (Hetch

Hetchy Reservoir) Tuolumne Tuolumne River

CA00124 Priest Tuolumne Rattlesnake Creek

CA00125 Cherry Valley Tuolumne Cherry Creek

CA00126 Calaveras Alameda Calaveras Creek

CA00127 Lower Crystal Springs San Mateo San Mateo Creek

CA00128 Pilarcitos San Mateo Pilarcitos Creek

CA00129 San Andreas San Mateo Trib San Mateo Creek

CA00132 James H Turner (San

Antonio Reservoir) Alameda San Antonio Creek

CA00138 Gibraltar Santa Barbara Santa Ynez River

CA00140 Lake Curry Napa Gordon Valley Creek

CA00142 Lake Frey Solano Wild Horse Creek

CA00149 Bell Canyon Napa Bell Creek

CA00155 Municipal Solano Trib Suisun Creek

CA00156 Newell Santa Cruz San Lorenzo River

CA00158 Cherry Flat Santa Clara Penitencia Creek

CA00161 Lake Anza (C L Tilden

Park) Contra Costa Wildcat Creek

CA00164 Jackson Creek Spillway

(Pardee) Amador Mokelumne River

CA00165 Chabot Alameda San Leandro Creek

CA00166 San Pablo Contra Costa San Pablo Creek

CA00173 Camanche Main San Joaquin Mokelumne River

CA00187 Big Dalton Los Angeles Big Dalton Wash

CA00188 Big Santa Anita Los Angeles Trib Rio Hondo

CA00189 Devils Gate Los Angeles Arroyo Seco

CA00190 Cogswell Los Angeles West Fork San Gabriel River

CA00191 Big Tujunga No. 1 Los Angeles Big Tujunga Creek

CA00192 Live Oak Los Angeles Live Oak Creek

112

CA00193 Pacoima Los Angeles Pacoima Creek

CA00194 Puddingstone Los Angeles Walnut Creek

CA00195 San Dimas Los Angeles San Dimas Creek

CA00196 Sawpit Los Angeles Sawpit Creek

CA00198 Thompson Creek Los Angeles Thompson Creek

CA00199 Puddingstone Diversion Los Angeles San Dimas Creek

CA00200 San Gabriel Los Angeles San Gabriel River

CA00204 Alpine Marin Lagunitas Creek

CA00205 Lagunitas Marin Lagunitas Creek

CA00206 Phoenix Lake Marin Ross Creek

CA00207 Bon Tempe Marin Lagunitas Creek

CA00208 Peters Marin Lagunitas Creek

CA00209 Seeger Marin Nicasio Creek

CA00211 Juncal Santa Barbara Santa Ynez River

CA00212 Mathews Riverside Trib Cajalco Creek

CA00214 Copper Basin San Bernardino Copper Basin

CA00216 Morris Los Angeles San Gabriel River

CA00223 Robert A Skinner Riverside Tucalota Creek

CA00224 Lake Gregory San Bernardino Houston Creek

CA00226 Anderson Cottonwood Shasta Sacramento River

CA00227 Camp Far West Yuba Bear River

CA00228 Weber El Dorado North Fork Webber Creek

CA00232 Jacobs Creek El Dorado Jacobs Creek

CA00233 Big Sage Modoc Rattlesnake Creek

CA00234 Cuyamaca San Diego Boulder Creek

CA00237 Littlerock Los Angeles Littlerock Creek

CA00239 Crocker Diversion

(Snelling Diversion) Merced Merced River

CA00240 New Exchequer (Lake

McClure) Mariposa Merced River

CA00242 McSwain Mariposa Merced River

CA00243 Modesto Res Stanislaus Trib Tuolumne River

CA00244 Dwinnell Dam (Shasta

River Dam) Siskiyou Shasta River

CA00245 Bowman Nevada Canyon Creek

CA00246 Deer Creek Diversion

(Lower Scotts Flat) Nevada Deer Creek

CA00247 French Lake Nevada Canyon Creek

CA00248 Milton Nevada/Sierra Middle Yuba River

CA00249 Lake Combie Nevada Bear River

CA00250 Sawmill Main Nevada Canyon Creek

CA00252 Jackson Lake Nevada Jackson Creek

CA00253 Scotts Flat Nevada Deer Creek

113

CA00254 Jackson Meadows Nevada Middle Fork Yuba River

CA00255 Rollins Nevada Bear River

CA00256 Faucherie Lake Main Nevada Canyon Creek

CA00257 Dutch Flat Afterbay Nevada/Placer Bear River

CA00260 Goodwin Calaveras Stanislaus River

CA00262 Rodden Lake Stanislaus Lesnini Creek

CA00263 Beardsley Tuolumne Middle Fork Stanislaus River

CA00264 Donnells Tuolumne Middle Fork Stanislaus River

CA00265 Tulloch Calaveras Stanislaus River

CA00266 Beardsley Afterbay Tuolumne Middle Fork Stanislaus River

CA00267 Wyandotte, Lake Butte North Honcut Creek

CA00268 Lost Creek Butte Lost Creek

CA00269 Little Grass Valley Plumas South Fork Feather River

CA00270 South Fork Diversion Plumas South Fork Feather River

CA00271 Slate Creek Plumas Slate Creek

CA00272 Sly Creek Butte Lost Creek

CA00273 Forbestown Diversion Butte South Fork Feather River

CA00274 Ponderosa Butte South Fork Feather River

CA00276 Woodward Stanislaus Simmons Creek

CA00277 Concow Butte Concow Creek

CA00278 La Grange Stanislaus Tuolumne River

CA00281 Don Pedro Main Tuolumne Tuolumne River

CA00283 Henshaw San Diego San Luis Rey River

CA00284 Bridgeport Mono East Walker Rv

CA00285 Woodbridge Div San Joaquin Mokelumne River

CA00287 Coyote Santa Clara Coyote Creek

CA00288 Calero Santa Clara Calero Creek

CA00289 Almaden Santa Clara Almitos Creek

CA00290 Guadalupe Santa Clara Guadalupe Creek

CA00291 Vasona Percolating Santa Clara Los Gatos Creek

CA00292 Stevens Creek Santa Clara Stevens Creek

CA00293 James J. Lenihan

(Lexington) Santa Clara Los Gatos Creek

CA00294 Anderson Santa Clara Coyote River

CA00296 Magalia Butte Little Butte Creek

CA00297 Paradise Butte Little Butte Creek

CA00298 Santiago Creek Orange Santiago Creek

CA00299 North Fork (Pacheco Dam) Santa Clara Pacheco Creek

CA00300 West Valley Modoc West Valley Creek

CA00301 Peoples Weir Kings Kings River

CA00303 Island Weir Kings North Fork Kings River

CA00304 Fairmount Park Riverside Trib Santa Ana River

CA00305 Mockingbird Canyon Riverside Mockingbird Canyon

114

CA00306 Redhawk Lake Calaveras Rich Gulch

CA00307 Middle Fork Diversion Tulare Middle Fork Kaweah River

CA00310 Kimball Creek Napa Kimball Creek

CA00312 Matilija Ventura Matilija Creek

CA00313 Runkle Ventura Runkle Canyon

CA00321 Novato Creek Marin Novato Creek

CA00323 Copco No 1 Siskiyou Klamath River

CA00325 Iron Gate Siskiyou Klamath River

CA00326 Butt Valley Plumas Butt Creek

CA00327 Lake Almanor Plumas North Fork Feather River

CA00328 Poe Butte North Fork Feather River

CA00329 Cresta Plumas North Fork Feather River

CA00330 Rock Creek Plumas North Fork Feather River

CA00331 Lower Bucks Lake (Bucks

Diversion) Plumas Bucks Creek

CA00332 Bucks Lake (Bucks

Storage) Plumas Bucks Creek

CA00333 Grizzly Forebay Plumas Grizzly Creek

CA00334 Three Lakes Plumas Milk Ranch Creek

CA00335 Balch Diversion Fresno North Fork Kings River

CA00336 Balch Afterbay Fresno North Fork Kings River

CA00337 Crane Valley (Bass Lake) Madera North Fork Willow Creek

CA00340 Kerckhoff Madera San Joaquin River

CA00341 Merced Falls Merced Merced River

CA00342 Manzanita Lake

(Manzanita Diversion) Madera North Fork Willow Creek

CA00344 Kunkle Butte Trib West Branch Feather

River

CA00345 Philbrook Butte Philbrook Creek

CA00346 Round Valley Butte West Branch Feather River

CA00351 Fuller Lake Nevada Jordan Creek

CA00356 Lake Arthur Placer South Fork Dry Creek

CA00357 Lake Fordyce Nevada Fordyce Creek

CA00358 Lake Spaulding Nevada South Fork Yuba River

CA00359 Lake Sterling Nevada Trib Fordyce Creek

CA00361 Lake Valley Main Placer Trib North Fork American

River

CA00363 Lower Feeley (Carr Lake) Nevada Trib Fall Creek

CA00364 Lower Lindsey Nevada Trib Texas Creek

CA00365 Lower Peak Lake

(Cascade Lakes) Placer Trib South Fork Tuba River

CA00366 Meadow Lake Nevada Trib Fordyce Creek

CA00367 Middle Lindsey Nevada Trib Texas Creek

CA00368 Rock Creek Main Placer Rock Creek

115

CA00369 Rucker Lake Nevada Rucker Creek

CA00370 Upper Feeley Lake Nevada Trib Fall Creek

CA00371 Upper Peak Lake

(Cascade Lakes) Placer Trib South Fork Yuba River

CA00373 White Rock Lake Nevada Trib North Creek

CA00374 Echo Lake El Dorado Echo Creek

CA00376 Medley Lakes Main (Lake

Aloha) El Dorado

Trib South Fork American

River

CA00377 Silver Lake Amador Silver Fork

CA00378 Caples Lake (Twin Lake) Alpine Trib Silver Fork

CA00379 Upper Bear Amador Bear River

CA00380 Lower Blue Lake Alpine Blue Creek

CA00381 Meadow Lake Alpine Trib North Fork Mokelumne

CA00382 Salt Springs Amador North Fork Mokelumne River

CA00384 Twin Lakes Alpine Trib North Fork Mokelumne

CA00385 Upper Blue Lake Alpine Blue Creek

CA00387 Lyons Tuolumne South Fork Stanislaus River

CA00388 Strawberry (Pinecrest) Tuolumne South Fork Stanislaus River

CA00389 Phoenix Tuolumne Sullivan Creek

CA00390 Relief Tuolumne Summit Creek

CA00393 Macumber Shasta North Fork Battle Creek

CA00394 North Battle Creek Shasta North Fork Battle Creek

CA00395 Pit No. 3 Diversion

(Britton Lake) Shasta Pit River

CA00397 Pit No. 4 Diversion Shasta Pit River

CA00398 Scott Lake Eel River

CA00399 Cape Horn Dam (Van

Arsdale Reservoir) Mendocino South Eel River

CA00400 Tiger Creek Regulator Amador Tiger Creek

CA00401 Tiger Creek Afterbay Amador North Fork Mokelumne River


CA00404 Hat Creek No. 2 Diversion

(Baum Lake) Shasta Hat Creek

CA00405 Pit No. 1 Forebay Shasta Fall River

CA00406 Morris Mendocino James Creek

CA00407 Indian Ole Lassen Hamilton Creek

CA00409 Lower Bear Amador Bear River

CA00411 Wishon Main Fresno North Fork Kings River

CA00412 Courtright Fresno Helms Creek

CA00413 Belden Forebay (Caribou

Afterbay) Plumas North Fork Feather River



CA00416 McCloud Diversion Shasta McCloud River

CA00417 Iron Canyon Shasta Iron Canyon Creek

116

CA00418 Chili Bar El Dorado South Fork American River

CA00421 New Drum Afterbay Nevada Bear River

CA00422 Alpine Main Alpine Silver Creek

CA00423 Hunters Calaveras Mill Creek

CA00424 Ross Calaveras French Gulch Creek

CA00426 Union Main Alpine North Fork Stanislaus River

CA00427 Utica Main Alpine North Fork Stanislaus River

CA00432 Big Creek Dam No. 6 Fresno San Joaquin River

CA00433 Florence Lake Fresno South Fork San Joaquin River

CA00434 Big Creek Dam No. 3a

(Huntington) Fresno Big Creek

CA00435 Lady Franklin Lake Tulare East Fork Kaweah River

CA00437 Shaver Lake Fresno Stevenson Creek

CA00440 Big Creek Dam No. 7

(Redinger Lake) Fresno San Joaquin River

CA00441 Vermilion (Edison) Fresno Mono Creek

CA00442 Portal Forebay Main Fresno Trib South Fork San Joaquin

CA00443 Mammoth Pool Fresno San Joaquin River

CA00446 Hillside Inyo South Fork Bishop Creek

CA00447 Longley Inyo McGee Creek

CA00448 Sabrina Inyo Middle Fork Bishop Creek

CA00450 Rush Creek Meadows Mono Rush Creek

CA00451 Lundy Lake Mono Mill Creek

CA00454 Agnew Lake Mono Rush Creek

CA00455 Saddlebag Mono Lee Vining Creek

CA00456 Tioga Lake Mono Glacier Creek

CA00457 Rhinedollar (Ellery Lake) Mono Lee Vining Creek

CA00459 McBrien Modoc Pit River

CA00461 SX (Essex) Modoc Trib Pit River

CA00462 Huffman Antelope Modoc Clover Swale

CA00463 Taylor (Taylor Creek No.

1) Modoc Taylor Creek

CA00464 Janes Flat Modoc Mosquito Creek

CA00465 Davis Creek Orchard Modoc Roberts Creek

CA00466 Capik Modoc Trib North Fork Pit River

CA00467 Big Dobe North (Baker

and Thomas Reservoir) Modoc Trib Rattlesnake Creek

CA00468 Big Dobe South (Baker


CA00471 Little Juniper Modoc Little Juniper Creek

CA00472 Graven Modoc Trib Canyon Creek

CA00473 Plum Canyon Modoc Plum Creek

CA00474 Ingals Swamp (Dorris

Brothers Reservoir) Modoc Ingals Swamp

117

CA00475 Payne Modoc Trib South Fork Pit River

CA00480 Duncan Creek Diversion Modoc Trib Pit River

CA00481 Rye Grass Swale Modoc Trib Canyon Creek

CA00482 White Modoc Trib Pit River

CA00483 Toreson Modoc Toms Creek

CA00484 Kramer Modoc Widow Valley Creek

CA00485 Roberts Modoc Trib Pit River

CA00486 Enquist Modoc Trib Olivers Can

CA00487 Danhauser Modoc Trib South Fork Pit River

CA00488 Upper Pasture Modoc Yankee Jim Slough

CA00489 Lookout Modoc Pit River

CA00491 Carpenter Wilson Modoc Cooley Gulch

CA00492 Leonard Johnson Modoc Dry Creek

CA00494 Donovan Modoc Rye Grass Swale

CA00495 Campbell Lake Siskiyou Shackleford Creek

CA00496 Ray Soule Reservoir Siskiyou Trib Little Shasta River

CA00509 Round Valley Lassen Round Val Cr

CA00510 Red Rock No 1 Lassen Red Rock Creek

CA00512 Silva Flat Lassen Juniper Creek

CA00513 Coyote Flat Lassen Coyote Creek

CA00514 Caribou Lake Lassen Susan River

CA00515 Hog Flat Lassen Tr Susan River

CA00516 Leavitt, Lake Lassen Tr Susan River

CA00517 McCoy Flat Lassen Susan River

CA00519 Buckhorn Lassen Buckhorn Creek

CA00522 Coon Camp Lassen Tr Horse Lake

CA00524 Branham Flat Lassen Branham Creek

CA00525 Heath Reservoir Lassen Slate Creek

CA00528 Rye Tehama Kendrick Creek

CA00530 Bidwell Lake Plumas North Canyon Creek

CA00531 Silver Lake Plumas Silver Creek

CA00532 Grizzly Creek Plumas Big Grizzly Creek

CA00533 Taylor Lake Plumas Trib Indian Creek

CA00534 Long Lake Plumas Gray Eagle Creek

CA00535 Palen Sierra Antelope Creek

CA00537 Donner Lake Nevada Donner Creek

CA00538 Lake Vera Nevada Rock Creek

CA00541 Pine Grove Nevada Little Shady Creek

CA00542 Bellett Nevada Trib Shady Creek

CA00546 Morning Star Res Placer North Forbes Creek

CA00548 Los Verjels Yuba Dry Creek

CA00551 Cannon Ranch Butte Trib Oregon Gulch

CA00554 York Hill Colusa Trib Bear Creek

118

CA00555 Rancho Rubini Colusa Trib Bear Creek

CA00556 E A Wright Glenn Small Creek

CA00558 Hamilton Glenn Trib Watson Creek

CA00560 Ridgewood Mendocino Forsythe Creek

CA00561 McNab Mendocino McNab Creek

CA00562 Bevans Creek Mendocino Bevans Creek

CA00563 Scout Lake Mendocino Trib Berry Creek

CA00564 Geunoc Lake (Detert

Lake) Lake Bucksnort Creek

CA00565 McCreary Lake Bucksnort Creek

CA00566 Bordeaux, Lake Lake Trib Bucksnort Creek

CA00571 Spring Valley Lake Wolf Creek

CA00572 Coyote Creek Lake Coyote Creek

CA00574 Catacoula Napa Maxwell Creek

CA00578 Henne Napa Angwin Branch

CA00581 Duvall Napa Trib Pope Creek

CA00583 Moskowite Napa Trib Capell Creek

CA00585 Dick Week Napa Trib Pope Creek

CA00586 William, Lake Napa Trib Milliken Creek

CA00591 Mallacomes Sonoma Foote Creek

CA00597 Green Valley Lake Solano Dug Road Gulch

CA00601 Blodgett Sacramento Laguna Creek

CA00602 Van Vleck Sacramento Trib Arkansas Creek

CA00605 Hamel Sacramento Trib Dry Creek

CA00607 Mark Edson El Dorado Pilot Creek

CA00608 Williamson No 1 El Dorado Trib Weber Creek

CA00610 D Agostini El Dorado Spanish Creek

CA00611 Big Canyon Creek El Dorado Big Canyon Creek

CA00612 Goffinet Amador Jackass Creek

CA00615 John Orr Amador Trib Jackson Creek

CA00617 Shenandoah Lake Amador Pigeon Creek

CA00618 Emery Calaveras McKinney Creek

CA00619 Bevanda Calaveras Trib Calaveras River

CA00620 Salt Springs Valley Calaveras Rock Creek

CA00621 McCarty Calaveras Trib Johnny Creek

CA00622 Mountain King Calaveras Clover Creek

CA00624 FlyInAcres Calaveras Moran Creek

CA00627 Flowers Calaveras Little Johns Creek

CA00628 Cherokee Calaveras Cherokee Creek

CA00629 Scott Lake Alpine Tr Wfk Carson R

CA00630 Crater Lake Alpine Crater Lake Creek

CA00631 Red Lake Alpine Red Lake Creek

119

CA00634 Kinney Meadows Alpine Tr Silver Creek

CA00635 Lower Kinney Lake Alpine Tr Silver Creek

CA00641 Heenan Lake Alpine Tr Efk Carson R

CA00643 Upper Twin Lake Mono Robinson Creek

CA00644 Lower Twin Lake Mono Robinson Creek

CA00646 Black Reservoir Mono Black Creek

CA00648 Poore Lake Reservoir Mono Poore Creek

CA00649 Twain Harte Tuolumne Trib Sullivan Creek

CA00652 Big Creek Tuolumne Big Creek

CA00653 Tuolumne Log Pond Tuolumne Turn Back Creek

CA00654 Orvis Stanislaus Buckham Gulch

CA00655 Gilmore San Joaquin Trib Mormon Slough

CA00656 Davis No 2 San Joaquin Trib Calaveras River

CA00657 Foothill Ranch San Joaquin Trib Calaveras River

CA00664 Lucerne, Lake San Mateo Arroyo De Los Frijoles

CA00665 Bean Hollow #2 (De Los

Frijoles) San Mateo Arroyo De Los Frijoles



CA00669 Searsville San Mateo Corte Madera Creek

CA00674 Notre Dame San Mateo Belmont Creek

CA00675 Grant Company 2 Santa Clara Arroyo Aguague

CA00676 Lake Ranch Santa Clara Beardsley Creek

CA00679 Williams Santa Clara Los Gatos Creek

CA00680 Austrian Santa Clara Los Gatos Creek

CA00688 Mill Creek Santa Cruz Mill Creek

CA00689 San Clemente Monterey Carmel River

CA00692 Los Padres Monterey Carmel River

CA00694 Hawkins San Benito Trib Arroyo De Las Viboras

CA00698 Kelsey Merced Trib South Fork Dry Creek

CA00699 Stockton Creek Mariposa Stockton Creek

CA00700 Green Valley Mariposa Smith Creek

CA00701 McMahon Mariposa Maxwell Creek

CA00702 Hendricks Head Diversion Butte Trib Horse Creek

CA00705 Sierra Vista Madera Chowchilla River

CA00706 Jane, Lake Madera Trib Hildreth Creek

CA00707 Black Hawk Madera Coarse Gold Creek

CA00708 Spring Madera Longhollow Creek

CA00709 Sequoia Lake Fresno Mill Flat Creek

CA00713 Empire Weir No 2 Kings South Fork Kings River

CA00719 Rancho Del Ciervo Santa Barbara Trib San Jose Creek

CA00724 Los Tablas Creek San Luis Obispo Las Tablas Creek

CA00725 Righetti San Luis Obispo West Corral De Pie

120

CA00726 San Marcos San Luis Obispo San Marcos Creek

CA00727 Hartzell San Luis Obispo Santa Rita Creek

CA00729 Tejon Storage 2 Kern Trib Tejon Creek

CA00731 Alisal Creek Santa Barbara Alisal Creek

CA00736 Lake Sherwood Ventura Potrero Valley Creek

CA00737 Eleanor, Lake Ventura Eleanor Creek

CA00739 Malibu Lake Club Los Angeles Malibu Creek

CA00742 Lindero Los Angeles Lindero Creek

CA00743 Potrero Los Angeles Potrero Valley

CA00745 Lambert Orange Trib Newport Bay

CA00746 Peters Canyon Orange Peters Canyon

CA00747 Bonita Canyon Orange Bonita Creek

CA00748 Laguna Orange Trib San Diego Creek

CA00750 Veeh Orange Trib San Diego Creek

CA00755 Chino Ranch #1 San Bernardino Tonner Canyon Creek

CA00757 Bear Valley San Bernardino Bear Creek

CA00758 Green Val Lake San Bernardino Green Valley Creek

CA00759 Lake Arrowhead San Bernardino Little Bear Creek

CA00760 Grass Valley San Bernardino Grass Valley Creek

CA00761 Rancho Cielito San Bernardino Trib Chino Creek

CA00763 Lake Hemet Riverside Trib San Jacinto River

CA00764 Little Lake Riverside Trib San Jacinto

CA00765 Railroad Canyon Riverside San Jacinto River

CA00766 Lee Lake Riverside Temescal Creek

CA00770 Vail Riverside Temecula Creek

CA00771 Quail Valley Riverside Trib San Jancinto River

CA00772 Wohlford Lake San Diego Escondido Creek

CA00774 Corte Madera San Diego Trib Pine Valley

CA00775 Sweetwater Main San Diego Sweetwater River

CA00776 Lake Loveland San Diego Sweetwater River

CA00777 Henry Jr San Diego Skye Valley

CA00780 Wuest San Diego Mc Cain Creek

CA00781 Calavera San Diego Calavera Creek

CA00782 San Marcos San Diego San Marcos Creek

CA00786 Thing Valley San Diego La Posta Creek

CA00789 Palo Verde San Diego Sweetwater River

CA00791 Healdsburg Recreation Sonoma Russian River

CA00794 Matanzas Creek Sonoma Matanzas Creek

CA00796 Woodcrest Riverside Woodcrest Creek

CA00797 Harrison Street Riverside Harrison Creek

CA00798 Alessandro Riverside Alessandro Creek

CA00799 Prenda Riverside Prenda Creek

121

CA00800 Sycamore Riverside Sycamore Canyon

CA00801 Pigeon Pass Riverside Pigeon Pass

CA00802 Boxsprings Riverside Box Springs Creek

CA00804 Lake Madrone Butte Berry Creek

CA00805 Santa Felicia Ventura Piru Creek

CA00806 Elmer J Chesbro Santa Clara Llagas Creek

CA00807 Uvas Santa Clara Uvas Creek

CA00808 Pine Creek Contra Costa Pine Creek

CA00809 Marsh Creek Contra Costa Marsh Creek

CA00810 Deer Creek Contra Costa Deer Creek

CA00811 Dry Creek Contra Costa Dry Creek

CA00812 Nacimiento San Luis Obispo Nacimiento River

CA00813 San Antonio Monterey San Antonio River

CA00814 Ice House Main El Dorado South Fork Silver Creek

CA00815 Junction El Dorado Silver Creek

CA00816 Union Valley El Dorado Silver Creek

CA00817 Camino El Dorado Silver Creek

CA00818 Gerle Creek El Dorado Gerle Creek

CA00820 Loon Lake Main El Dorado Gerle Creek

CA00821 Buck Island Main El Dorado Little Rubicon

CA00822 Rubicon Main El Dorado Rubicon River

CA00823 Slab Creek El Dorado South Fork American River

CA00824 Brush Creek El Dorado Brush Creek

CA00825 Rancho Seco Sacramento Trib Hadselville Creek

CA00827 Adobe Creek Lake Adobe Creek

CA00828 Highland Creek Lake Highland Creek

CA00829 Villa Park Orange Santiago Creek

CA00833 Ruth Lake (R. W.

Matthews) Trinity Mad River

CA00835 Berenda Slough Madera Berenda Slough

CA00837 Redbank Fresno Redbank Creek

CA00839 Ward Creek Alameda Ward Creek

CA00840 Cull Creek Alameda Cull Creek

CA00841 San Lorenzo Creek (Don

Castro) Alameda San Lorenzo Creek

CA00842 Virginia Ranch Yuba Dry Creek

CA00845 Copperopolis Calaveras Penney Creek

CA00847 Paicines San Benito Trib Tres Pinos Creek

CA00848 Hernandez San Benito San Benito River

CA00849 Russian River No 1 Sonoma Russian River

CA00850 Wood Ranch Ventura Trib Arroyo Simi

CA00851 Herman, Lake Solano Sulphur Springs Creek

CA00854 Sand Canyon Orange Sand Canyon

122

CA00856 L. L. Anderson (French

Meadows) Placer Middle Fork American River

CA00857 Hell Hole Placer Rubicon River

CA00858 Middle Fork Interbay Placer Middle Fork American River

CA00859 Ralston Afterbay Placer Middle Fork American River

CA00863 New Bullards Bar Yuba North Yuba River

CA00864 Our House Sierra Middle Fork Yuba River

CA00865 Log Cabin Yuba Oregon Creek

CA00866 Francis, Lake Yuba Dobbins Creek

CA00867 Jackson Creek Amador Jackson Creek

CA00871 Ada Rose, Lake Mendocino Trib Willets Creek

CA00872 Emily (Brooktrails 3

North) Mendocino Willits Creek

CA00873 Sulphur Creek Orange Sulphur Creek

CA00874 Maine Prairie 3 Solano Ulatis Creek

CA00878 Dixon San Diego Trib Escondido Creek

CA00886 Mendota Diversion

(Mendota Pool) Fresno San Joaquin River

CA00887 Lopez San Luis Obispo Arroyo Grande Creek

CA00888 Terminal San Luis Obispo Trib Arroyo Grande

CA00889 Box Canyon Siskiyou Sacramento River

CA00904 Westlake Reservoir Los Angeles Tree Springs Creek

CA00905 Turner San Diego Moosa Canyon

CA00906 San Dieguito San Diego Trib Escondido Creek

CA00909 Poway San Diego Warren Canyon

CA00910 Holiday Lake El Dorado Sawmill Creek

CA00911 Cache Creek (Clear Lake) Lake Cache Creek

CA00914 Lindauer Concrete Modoc Pit River

CA00915 A And C (Avenzino Res) Modoc South Fork Willow Creek

CA00916 Poison Springs Modoc Rock Creek

CA00920 Bayley Res Modoc Crooks Canyon

CA00921 Renner Sibley Cr Modoc Sibley Creek

CA00922 Boggs And Warren Modoc East Sand Creek

CA00925 James Porter Modoc Trib Parker Creek

CA00926 Shelley Siskiyou Webb Gulch

CA00929 Dwight Hammond Siskiyou Trib Shasta River

CA00933 Null Shasta Rock Creek

CA00934 Ross No 1 Shasta Trib Stillwater Creek

CA00938 Peconom Lassen Antelope Val

CA00940 Cramer Lassen Tr Horse Lake

CA00941 Gerig Lassen Pit River

CA00942 Mendiboure Lassen Tr Van Loan Cr

CA00944 Smoke Creek (W) Lassen Smoke Creek

123

CA00945 Holbrook Lassen Ash Creek

CA00946 Iverson Lassen Trib Juniper Creek

CA00947 Elkins And Lane Lassen Trib Ash Creek

CA00948 Albaugh No 1 Lassen Trib Pit River

CA00949 Albaugh No 2 Lassen Trib Willow Creek

CA00952 Spaulding Lassen Tr Madelin Plains

CA00953 Myers Lassen Trib Ash Creek

CA00954 Madeline Lassen Tr Madeline Plains

CA00956 Tule Lake (Moon Lake) Lassen Cedar Creek

CA00957 Spooner Lassen Trib Ash Creek

CA00960 Leonard No 2 Lassen Trib Ash Creek

CA00961 Petes Valley Lassen Petes Creek

CA00964 Anthony House Nevada Deer Creek

CA00965 Swan Nevada Dry Creek

CA00966 Magnolia Nevada Magnolia Creek

CA00969 Lakewood Placer Dry Creek

CA00971 Ice Lakes Placer Serena Creek

CA00973 Williams Valley Mendocino Trib Short Creek

CA00974 Round Mountain Mendocino Trib York Creek

CA00976 McGuire Mendocino South Fork Noyo River

CA00979 Olsen Shasta Ledgewood Creek

CA00997 Indian Creek El Dorado Indian Creek

CA00998 Barnett El Dorado Barnett Creek

CA01001 Volo Mining Company El Dorado Indian Creek

CA01002 Tanner Calaveras Cowell Creek

CA01005 White Pines Calaveras San Antonio Creek

CA01008 Pomponio Ranch San Mateo Pomponio Creek

CA01010 Green Oaks #1 San Mateo Green Oaks Creek

CA01011 Coit Santa Clara Trib North Fork Pacheco Creek

CA01013 Murry Santa Clara Mississippi Creek

CA01015 R Simoni Irrigation Santa Clara Hay Canyon

CA01016 Laurel Springs Club Santa Clara Middle Fork Coyote Creek

CA01027 Misselbeck Shasta North Fork Cottonwood

CA01028 Truett Shasta Ash Creek

CA01029 Nash Shasta Trib Stillwater Creek

CA01030 Haynes Res Shasta Goose Creek

CA01045 Schubin El Dorado Trib Webber Creek

CA01046 Manhattan Creek El Dorado Manhattan Creek

CA01048 Aeree El Dorado Trib Pilot Creek

CA01050 Patterson El Dorado Deadman Creek

CA01052 Thurman (Hawkeye

Ranch) Shasta Slaughter Pole

CA01055 Eaton H. Magoon Lake Napa Routan Creek

124

(Upper Bohn Lake)

CA01059 Budge Sonoma Trib Russian River

CA01062 Pinheiro Sonoma Trib Petaluma River

CA01064 Straza El Dorado Black Rock Creek

CA01065 Abrams El Dorado Hastings Creek

CA01067 Hillside Ranch Sonoma Trib House Creek

CA01075 Big Dry Creek Fresno Big Dry Cr & Do

CA01076 Chorro Creek San Luis Obispo Chorro Creek

CA01082 New U San Leandro Alameda San Leandro Creek

CA01083 Soulajule Marin Arroyo Sausal

CA01086 Camp Far West Diversion Yuba Bear River

CA01088 Cloverswale Modoc Trib Witcher Creek

CA01097 Mustang Creek Merced Mustang Creek

CA01098 Bravo Lake Reservoir Tulare Wutchumna Ditch

CA01101 Eagle Ranch San Luis Obispo Hale Creek

CA01107 Indian Valley Lake North Fork Cache Creek

CA01115 Top Cat Tehama Trib Brannin Creek

CA01116 Sunflower Tehama Sunflower Gulch

CA01119 Clementia Sacramento Trib Cosumnes River

CA01122 Mission Viejo, Lake Orange Oso Creek

CA01123 Trampas Canyon Orange Trampas Canyon

CA01131 Yucaipa No 1 San Bernardino Trib Yucaipa Creek

CA01132 Yucaipa No 2 San Bernardino Trib Yucaipa Creek

CA01145 Upper Oso Orange Oso Creek

CA01158 Sierra Madre Villa Los Angeles Sierra Madre Canyon

CA01179 Oak Street Riverside Oak Street Creek

CA01180 Sand Creek Tulare Sand Creek

CA01199 Cameron Park El Dorado Deer Creek

CA01205 Homestake Tailings Lake Trib Hunting Creek

CA01208 Halls Meadows Modoc Couch Creek

CA01211 Mary Street Riverside Alessandro Wash

CA01213 Antelope Kern Antelope Creek

CA01215 Ramona San Diego Green Val Road Creek

CA01216 Steidlmayer #3 Sutter Unnamed

CA01217 Las Llajas Ventura Las Llajas Can

CA01223 Davis Creek Yolo Davis Creek

CA01224 New Spicer Meadow Tuolumne Highland Creek

CA01225 Galt Sacramento Trib Laguna Creek

CA01230 Lakeport Lake Trib Manning Creek

CA01234 North Fork Diversion Alpine North Fork Stanislaus River

CA01238 Isabel Lake No 1 Santa Clara Trib Isabel Creek

CA01240 Edwards Reservoir Santa Barbara Trib Gato Creek

125

CA01246 Centennial Mendocino Davis Creek

CA01248 Dove Canyon Orange Dove Creek

CA01250 Smiths Reservoir Merced Trib Burns Creek

CA01251 Rubber Dam 3 Alameda Alameda Creek

CA01252 Pine Creek Detention Contra Costa Pine Creek


CA01257 McKays Point Diversion Calaveras North Fork Stanislaus River

CA01262 Jayne s Lake Mendocino Toney Creek

CA01263 Bradford Mendocino Trib Russian River

CA01265 Bottoms Lake Trib Helena Creek

CA01266 Sycamore Canyon Ventura Sycamore Can

CA01270 California Park Butte Dead Horse Slough

CA01289 Metcalf Napa Trib Maxwell Creek

CA01303 Flotation Tails Calaveras Trib Littlejohns Creek

CA01306 Middle Cooperstown Tuolumne Trib Dry Creek

CA01307 Kilmer Tuolumne Trib Dry Creek

CA01309 Shaffer El Dorado Indian Creek

CA01313 Merlo Sonoma Fall Creek

CA01314 Wallace Calaveras Trib Bear Creek

CA01315 Lagoon Valley County

Park Solano Trib Laguna Creek

CA01327 Fancher Creek Fresno Fancher Cr & Hog Creek

CA01335 Golden Rule Mendocino Trib Walker Creek


CA01355 Castle Merced Canal Creek

CA01361 Agua Chinon Orange Agua Chinon Wash


CA01406 Amargosa Creek Los Angeles Amargosa Creek

CA01408 SVCSD Reclamation Pond

2 (Hooper No. 2) Mendocino Trib Mcdowell Creek

CA01412 Arundell Barranca Ventura Arundell Barranca

CA01423 Lolonis Vineyards Mendocino Trib West Fork Russian River

CA01425 Jack s Swamp Dam No 2 Modoc Trib Pit River

CA01428 Skyrocket Calaveras Littlejohn Creek

CA01450 Upper Wilcox Madera Unnamed Tributary To

Picayunne Creek

CA10019 Hansen Los Angeles Tujunga Wash

CA10020 Lopez Los Angeles Pacoima Wash

CA10021 Mojave Dam San Bernardino W Fk Mojave River

CA10023 San Antonio Dam San Bernardino San Antonio Creek

CA10024 Santa Fe Los Angeles San Gabriel River

CA10025 Sepulveda Los Angeles Los Angeles River

CA10027 Whittier Narrows Dam Los Angeles San Gabriel River

CA10101 Bear Mariposa Bear Creek

126

CA10102 Black Butte Tehama Stony Creek

CA10103 Burns Merced Burns Creek

CA10104 Farmington Dam San Joaquin Rock And Littlejohn Creeks

CA10105 Englebright Yuba Yuba River

CA10106 Isabella Kern Kern River

CA10107 Mariposa Dam Mariposa Mariposa Creek

CA10108 Martis Creek Nevada Martis Creek

CA10109 New Hogan Dam Calaveras Calaveras River

CA10110 North Fork Placer North Fork American River

CA10111 Owens Dam Mariposa Owens Creek

CA10112 Pine Flat Fresno Kings River

CA10113 Success Tulare Tule River

CA10114 Terminus (Lake Kaweah) Tulare Kaweah River

CA10123 Hughes (Dam #36) Monterey Aqua Fria Creek

CA10131 Lake Oneill San Diego Santa Margarita River

Offstream

CA10134 Antelope Shasta Pit River

CA10135 Boca Nevada Little Truckee River

CA10136 Bradbury Santa Barbara Santa Ynez River

CA10139 Casitas Ventura Coyote Creek

CA10141 Clear Lake Modoc Lost River

CA10144 Dorris Modoc Stockdill Slough

CA10145 East Park Dike No. 1 (N) Colusa Little Stony Creek

CA10148 Folsom Sacramento American River

CA10154 Friant Fresno San Joaquin River

CA10156 Glen Anne Santa Barbara West Fork Glen Annie Canyon

CA10159 Imperial Diversion Imperial Colorado River

CA10160 Keswick Shasta Sacramento River

CA10162 Lake Tahoe Placer Truckee River

CA10163 Lauer Modoc Trib Pit River

CA10164 Lauro Santa Barbara Diablo Creek

CA10165 Lewiston Trinity Trinity River

CA10166 Little Panoche Detention Fresno Little Panoche Creek

CA10167 Los Banos Creek

Detention Dam Merced Los Banos Creek

CA10169 McGinty Modoc Mud Creek

CA10170 Monticello Yolo Putah Creek

CA10174 Nimbus Sacramento American River

CA10179 Prosser Creek Nevada Prosser Creek

CA10180 Putah Diversion Yolo, Solano Putah Creek

CA10181 Red Bluff Diversion Tehama Sacramento River

CA10186 Shasta Shasta Sacramento River

CA10187 Sly Park (Jenkinson) El Dorado Sly Park Creek

127

CA10192 Stampede Sierra Little Truckee River

CA10194 Stony Gorge Glenn Stony Creek

CA10196 Trinity Trinity Trinity River

CA10197 Twitchell San Luis Obispo Cuyama River

CA10201 Coyote Valley Dam Mendocino East Fork Russian River

CA10202 Salinas San Luis Obispo Salinas River

CA10204 Whiskeytown Shasta Clear Creek

CA10207 Emigrant Lake Tuolumne North Fork Cherry Creek

CA10210 Telephone Flat Modoc Trib Boles Creek

CA10212 Y Meadow Tuolumne Rock Creek

CA10213 Walker Mine Tails Plumas Dolly Creek

CA10216 Fallen Leaf El Dorado Taylor Creek

CA10219 Snow Lake Tuolumne Trib East Fork Cherry Creek

CA10220 Middle Emigrant Tuolumne North Fork Cherry Creek

CA10221 Upper Buck Lake Tuolumne Buck Meadow Creek

CA10222 Long Lake Tuolumne West Fork Cherry Creek

CA10224 Herring Creek Tuolumne Herring Creek

CA10225 Bear Lake Tuolumne Lily Creek

CA10226 Leighton Lake Tuolumne Yellow Hammer Creek

CA10227 Swains Hole Lassen Butte Creek

CA10228 Lower Salmon Lake Sierra Trib Salmon Creek

CA10229 U Salmon Lake Sierra Trib Salmon Creek

CA10232 Weaver Nevada Eastfork

CA10233 Blue Lake Lassen Outlet Creek

CA10239 Smith Lake Plumas Wapaunsie Creek

CA10243 Buchanan Madera Chowchilla River

CA10244 Hidden Dam Madera Fresno River

CA10245 Funks Colusa Funks Creek

CA10246 New Melones Calaveras Stanislaus River

CA10266 Manzanita Lake Shasta Manzanita Creek

CA10301 Laguna Imperial Colorado River

CA10302 Upper Letts Colusa Letts Creek

CA10303 Warm Springs Sonoma Dry Creek

CA10305 Parker San Bernardino Colorado River

CA10306 Sugar Pine Placer North Shirttail Creek

CA10307 Hume Lake Fresno Ten Mile Creek

CA10308 Twin Lakes Mono Mammoth Creek

CA10313 Everly Modoc Long Branch Cyn

CA10318 South Mountain Modoc Trib Fletcher Creek

CA10320 Green Tank Modoc Trib Fletcher Creek

CA10321 Crowder Mountain Modoc Trib Telephone Flat

CA10323 San Justo San Benito Offstream

CA10324 Seven Oaks San Bernardino Santa Ana River

128

CA10325 Miners Ravine Detention Modoc Trib Clover Swale Creek

CA10326 Boles Meadow Modoc Boles Creek

CA10327 Cummings Res No 2 Modoc Pit River Trib

CA10329 Grass Lake Plumas Little Jamison Creek

CA10330 Jamison Lake Plumas Little Jamison Creek

CA10331 Upper Sardine Lake Sierra Trib Sardine Creek

CA10336 Bear Valley Lassen Little Davis Creek

CA10337 Four Mile Valley No 4 Modoc Fountain Creek

CA10339 Emigrant Springs Modoc Null

CA10340 East Boulder Siskiyou East Boulder Creek

CA10342 Brown Mtn Barrier Los Angeles Arroyo Seco

CA10351 Lower Biscar Lassen Snowstorm Creek

CA10352 Upper Biscar Lassen Snowstorm Creek

CA10354 Nelson Corral Lassen Dry Creek

CA20042 Salton Sea Dike Imperial None

CA82402 Bayley Modoc Trib Fletcher Creek

CA82412 Highland Lake El Dorado Trib Rubicon River

CA82491 Pretty Tree (Emigrant

Flat Res) Modoc North Fork Pit River

CA82501 Wood Flat Modoc North Fork Pit River

CA82504 Deer Hill Modoc Trib Fletcher Creek

CA82531 Kern No 3 Tulare Kern River

CA82904 Rainbow Diversion Colusa Stoney Creek

CA82938 Buckhorn Trinity Grass Valley Creek

CA83069 Chilkoot Madera Chilkoot Creek

CA83151 Pit No. 7 Afterbay Shasta Pit River

CA83281 Pit River Weir Shasta Pit River

CA83283 Bear Creek Div Fresno Bear Creek

CA83288 Schaads Reservoir (CPUD

Middle Fork) Calaveras Middle Fork Mokelumne River

129

APPENDIX C

MODEL PERFORMANCE EVALUATION

Model performance was evaluated by comparing model predictions of mean monthly,

maximum 1-day and annual flows at unimpaired, reference gages (Carlisle et al. 2010a) in

California with observed flow records. The reference gages used to assess model

performance were excluded from the model calibration dataset.

Mean monthly flows, California Inland Mountain Region

January

r-squared 0.947

rmse 119.232

RSR 0.241

Percent bias -2.437

Nash-Sutcliff 0.941

February

r-squared 0.947

rmse 105.658

RSR 0.234

Percent bias -2.526

Nash-Sutcliff 0.945

March

r-squared 0.947

rmse 92.315

RSR 0.231

Percent bias -1.219

Nash-Sutcliff 0.946

April

r-squared 0.950

rmse 92.742

RSR 0.227

Percent bias -2.051

Nash-Sutcliff 0.948

May

r-squared 0.951

rmse 142.362

RSR 0.236

Percent bias -5.568

Nash-Sutcliff 0.944

130

June

r-squared 0.971

rmse 115.087

RSR 0.195

Percent bias -5.164

Nash-Sutcliff 0.962

July

r-squared 0.926

rmse 102.356

RSR 0.335

Percent bias -2.381

Nash-Sutcliff 0.886

August

r-squared 0.863

rmse 57.209

RSR 0.371

Percent bias 2.647

Nash-Sutcliff 0.861

September

r-squared 0.896

rmse 38.840

RSR 0.323

Percent bias -2.892

Nash-Sutcliff 0.895

October

r-squared 0.876

rmse 46.340

RSR 0.361

Percent bias -4.408

Nash-Sutcliff 0.868

November

r-squared 0.908

rmse 118.055

RSR 0.322

Percent bias -3.183

Nash-Sutcliff 0.895

December

r-squared 0.942

rmse 123.399

RSR 0.248

Percent bias -1.575

Nash-Sutcliff 0.938

131

Annual Maximum 1-day Flow, California Inland Mountain Region

r-squared 0.907

rmse 955.224

RSR 0.334

Percent bias -6.282

Nash-Sutcliff 0.887

Annual Mean , California Inland Mountain Region

r-squared 0.956

rmse 71.925

RSR 0.230

Percent bias -3.042

Nash-Sutcliff 0.947

Mean monthly flows, California Coastal Mountain Region

January

r-squared 0.967

rmse 368.921

RSR 0.187

Percent bias -0.368

Nash-Sutcliff 0.964

February

r-squared 0.978

rmse 292.530

RSR 0.163

Percent bias -3.628

Nash-Sutcliff 0.973

March

r-squared 0.973

rmse 270.338

RSR 0.179

Percent bias -2.595

Nash-Sutcliff 0.967

April

r-squared 0.974

rmse 162.876

RSR 0.161

Percent bias -1.274

Nash-Sutcliff 0.974

May

r-squared 0.916

rmse 209.934

RSR 0.295

132

Percent bias 4.033

Nash-Sutcliff 0.911

June

r-squared 0.902

rmse 162.796

RSR 0.318

Percent bias 3.877

Nash-Sutcliff 0.897

July

r-squared 0.901

rmse 110.874

RSR 0.335

Percent bias 10.173

Nash-Sutcliff 0.886

August

r-squared 0.847

rmse 94.363

RSR 0.416

Percent bias 7.247

Nash-Sutcliff 0.824

September

r-squared 0.924

rmse 70.302

RSR 0.284

Percent bias 4.018

Nash-Sutcliff 0.918

October

r-squared 0.979

rmse 93.191

RSR 0.167

Percent bias 2.898

Nash-Sutcliff 0.972

November

r-squared 0.960

rmse 321.465

RSR 0.212

Percent bias -6.312

Nash-Sutcliff 0.954

December

r-squared 0.971

rmse 349.730

RSR 0.181

Percent bias -3.657

133

Nash-Sutcliff 0.967

Maximum 1-day Flow, California Coastal Mountain Region

r-squared 0.894

rmse 3889.397

RSR 0.327

Percent bias -4.099

Nash-Sutcliff 0.891

Annual Mean , California Coastal Mountain Region

r-squared 0.971

rmse 163.390

RSR 0.170

Percent bias -0.729

Nash-Sutcliff 0.971

Mean monthly flows, California Xeric Regions

January

r-squared 0.701

rmse 4.550

RSR 0.541

Percent bias 3.511

Nash-Sutcliff 0.701

February

r-squared 0.781

rmse 3.355

RSR 0.466

Percent bias 3.689

Nash-Sutcliff 0.778

March

r-squared 0.779

rmse 3.613

RSR 0.465

Percent bias 2.911

Nash-Sutcliff 0.779

April

r-squared 0.783

rmse 3.689

RSR 0.461

Percent bias 2.570

Nash-Sutcliff 0.783

May

r-squared 0.736

rmse 4.618

RSR 0.512

Percent bias 4.946

134

Nash-Sutcliff 0.732

June

r-squared 0.642

rmse 5.779

RSR 0.593

Percent bias 1.502

Nash-Sutcliff 0.641

July

r-squared 0.474

rmse 8.155

RSR 0.718

Percent bias -0.339

Nash-Sutcliff 0.474

August

r-squared 0.438

rmse 8.946

RSR 0.743

Percent bias -0.612

Nash-Sutcliff 0.437

September

r-squared 9.398

rmse 0.775

RSR -0.496

Percent bias 0.386

Nash-Sutcliff

October 0.410

r-squared 9.419

rmse 0.764

RSR 0.010

Percent bias 0.404

Nash-Sutcliff

November

r-squared 0.519

rmse 7.340

RSR 0.688

Percent bias -0.062

Nash-Sutcliff 0.516

December

r-squared 0.556

rmse 6.210

RSR 0.660

Percent bias 0.686

Nash-Sutcliff 0.556

135

Annual Mean , California Xeric Regions

r-squared 0.504

rmse 29.219

RSR 0.699

Percent bias -1.097

Nash-Sutcliff 0.500

136

APPENDIX D

LIST OF CANDIDATE DAMS

NID Dam Name County River

CA01361 Agua Chinon Orange Agua Chinon Wash

CA00949 Albaugh No 2 Lassen Trib Willow Creek

CA00798 Alessandro Riverside Alessandro Creek

CA00731 Alisal Creek Santa Barbara Alisal Creek

CA00289 Almaden Santa Clara Almitos Creek

CA00204 Alpine Marin Lagunitas Creek

CA00294 Anderson Santa Clara Coyote River

CA00226 Anderson Cottonwood Shasta Sacramento River

CA00964 Anthony House Nevada Deer Creek

CA00106 Barrett San Diego Cottonwood Creek



CA00757 Bear Valley San Bernardino Bear Creek

CA00835 Berenda Slough Madera Berenda Slough

CA00467 Big Dobe North (Baker


CA00468 Big Dobe South (Baker


CA01075 Big Dry Creek Fresno Big Dry Cr & Do

CA00233 Big Sage Modoc Rattlesnake Creek

CA10102 Black Butte Tehama Stony Creek

CA10135 Boca Nevada Little Truckee River

CA00922 Boggs And Warren Modoc East Sand Creek

CA00207 Bon Tempe Marin Lagunitas Creek

CA00747 Bonita Canyon Orange Bonita Creek

CA00088 Bouquet Canyon Los Angeles Bouquet Creek

CA00802 Boxsprings Riverside Box Springs Creek

CA10136 Bradbury Santa Barbara Santa Ynez River

CA00284 Bridgeport Mono East Walker Rv

CA10342 Brown Mtn Barrier Los Angeles Arroyo Seco

CA00781 Calavera San Diego Calavera Creek

CA00126 Calaveras Alameda Calaveras Creek

CA00288 Calero Santa Clara Calero Creek

CA10139 Casitas Ventura Coyote Creek

137

CA00044 Castaic Los Angeles Castaic Creek

CA01355 Castle Merced Canal Creek

CA00165 Chabot Alameda San Leandro Creek

CA00067 Chatsworth Los Angeles Trib Los Angeles River

CA00158 Cherry Flat Santa Clara Penitencia Creek

CA01119 Clementia Sacramento Trib Cosumnes River

CA01088 Cloverswale Modoc Trib Witcher Creek

CA01011 Coit Santa Clara Trib North Fork Pacheco Creek

CA00104 Conn Creek Napa Conn Creek

CA00214 Copper Basin San Bernardino Copper Basin

CA10201 Coyote Valley Dam Mendocino East Fork Russian River

CA00239 Crocker Diversion

(Snelling Diversion) Merced Merced River

CA00840 Cull Creek Alameda Cull Creek

CA00487 Danhauser Modoc Trib South Fork Pit River

CA00656 Davis No 2 San Joaquin Trib Calaveras River

CA00246 Deer Creek Diversion

(Lower Scotts Flat) Nevada Deer Creek

CA00043 Del Valle Alameda Arroyo Valley

CA00537 Donner Lake Nevada Donner Creek

CA01248 Dove Canyon Orange Dove Creek

CA00068 Dry Canyon Los Angeles Dry Canyon Creek

CA00811 Dry Creek Contra Costa Dry Creek

CA00244 Dwinnell Dam (Shasta

River Dam) Siskiyou Shasta River

CA01240 Edwards Reservoir Santa Barbara Trib Gato Creek

CA00111 El Capitan San Diego San Diego River

CA00806 Elmer J Chesbro Santa Clara Llagas Creek

CA10105 Englebright Yuba Yuba River

CA00486 Enquist Modoc Trib Olivers Can

CA10313 Everly Modoc Long Branch Cyn

CA10216 Fallen Leaf El Dorado Taylor Creek

CA01327 Fancher Creek Fresno Fancher Cr & Hog Creek

CA10104 Farmington Dam San Joaquin Rock And Littlejohn Creeks

CA10148 Folsom Sacramento American River

CA00657 Foothill Ranch San Joaquin Trib Calaveras River

CA00138 Gibraltar Santa Barbara Santa Ynez River

CA00655 Gilmore San Joaquin Trib Mormon Slough

CA10156 Glen Anne Santa Barbara West Fork Glen Annie Canyon

CA00260 Goodwin Calaveras Stanislaus River

138

CA00675 Grant Company 2 Santa Clara Arroyo Aguague

CA00089 Grant Lake Mono Rush Creek

CA00472 Graven Modoc Trib Canyon Creek

CA00290 Guadalupe Santa Clara Guadalupe Creek

CA00605 Hamel Sacramento Trib Dry Creek

CA10019 Hansen Los Angeles Tujunga Wash

CA00797 Harrison Street Riverside Harrison Creek

CA00694 Hawkins San Benito Trib Arroyo De Las Viboras

CA01030 Haynes Res Shasta Goose Creek

CA00525 Heath Reservoir Lassen Slate Creek

CA00641 Heenan Lake Alpine Tr Efk Carson R

CA00848 Hernandez San Benito San Benito River

CA00108 Hodges, Lake San Diego San Dieguito River

CA10123 Hughes (Dam #36) Monterey Aqua Fria Creek

CA00474 Ingals Swamp (Dorris

Brothers Reservoir) Modoc Ingals Swamp


CA00946 Iverson Lassen Trib Juniper Creek

CA01425 Jack s Swamp Dam No 2 Modoc Trib Pit River

CA00132 James H Turner (San

Antonio Reservoir) Alameda San Antonio Creek

CA00706 Jane, Lake Madera Trib Hildreth Creek

CA00211 Juncal Santa Barbara Santa Ynez River

CA82531 Kern No 3 Tulare Kern River

CA10160 Keswick Shasta Sacramento River

CA00278 La Grange Stanislaus Tuolumne River

CA00748 Laguna Orange Trib San Diego Creek

CA00161 Lake Anza (C L Tilden

Park) Contra Costa Wildcat Creek

CA00759 Lake Arrowhead San Bernardino Little Bear Creek

CA00140 Lake Curry Napa Gordon Valley Creek

CA00142 Lake Frey Solano Wild Horse Creek

CA00224 Lake Gregory San Bernardino Houston Creek

CA00763 Lake Hemet Riverside Trib San Jacinto River

CA10131 Lake Oneill San Diego Santa Margarita River

Offstream

CA01230 Lakeport Lake Trib Manning Creek

CA00745 Lambert Orange Trib Newport Bay

CA01217 Las Llajas Ventura Las Llajas Can

CA10164 Lauro Santa Barbara Diablo Creek

139

CA10165 Lewiston Trinity Trinity River

CA00090 Long Valley Mono Owens River

CA00887 Lopez San Luis Obispo Arroyo Grande Creek

CA10167 Los Banos Creek

Detention Dam Merced Los Banos Creek

CA00127 Lower Crystal Springs San Mateo San Mateo Creek

CA00635 Lower Kinney Lake Alpine Tr Silver Creek

CA00076 Lower San Fernando

(Lower Van Norman) Los Angeles San Fernando Creek

CA00644 Lower Twin Lake Mono Robinson Creek

CA00027 Madera Lake Madera Fresno River

CA00739 Malibu Lake Club Los Angeles Malibu Creek

CA10108 Martis Creek Nevada Martis Creek

CA00212 Mathews Riverside Trib Cajalco Creek

CA00312 Matilija Ventura Matilija Creek

CA00459 McBrien Modoc Pit River

CA10169 McGinty Modoc Mud Creek

CA00886 Mendota Diversion

(Mendota Pool) Fresno San Joaquin River

CA10325 Miners Ravine Detention Modoc Trib Clover Swale Creek

CA01122 Mission Viejo, Lake Orange Oso Creek

CA00305 Mockingbird Canyon Riverside Mockingbird Canyon

CA00243 Modesto Res Stanislaus Trib Tuolumne River

CA10021 Mojave Dam San Bernardino W Fk Mojave River

CA00110 Morena San Diego Cottonwood Creek

CA00216 Morris Los Angeles San Gabriel River

CA00155 Municipal Solano Trib Suisun Creek

CA01013 Murry Santa Clara Mississippi Creek

CA00812 Nacimiento San Luis Obispo Nacimiento River

CA01029 Nash Shasta Trib Stillwater Creek

CA10109 New Hogan Dam Calaveras Calaveras River

CA10246 New Melones Calaveras Stanislaus River

CA01082 New U San Leandro Alameda San Leandro Creek

CA00156 Newell Santa Cruz San Lorenzo River

CA10174 Nimbus Sacramento American River

CA00321 Novato Creek Marin Novato Creek

CA00847 Paicines San Benito Trib Tres Pinos Creek

CA00475 Payne Modoc Trib South Fork Pit River

CA00301 Peoples Weir Kings Kings River

CA00208 Peters Marin Lagunitas Creek

140

CA00746 Peters Canyon Orange Peters Canyon

CA00206 Phoenix Lake Marin Ross Creek

CA00801 Pigeon Pass Riverside Pigeon Pass

CA00128 Pilarcitos San Mateo Pilarcitos Creek

CA10112 Pine Flat Fresno Kings River

CA00098 Pleasant Valley Inyo Owens River

CA00916 Poison Springs Modoc Rock Creek

CA00743 Potrero Los Angeles Potrero Valley

CA00909 Poway San Diego Warren Canyon

CA00799 Prenda Riverside Prenda Creek

CA10179 Prosser Creek Nevada Prosser Creek

CA00194 Puddingstone Los Angeles Walnut Creek

CA10180 Putah Diversion Yolo, Solano Putah Creek

CA00771 Quail Valley Riverside Trib San Jancinto River

CA00765 Railroad Canyon Riverside San Jacinto River

CA01215 Ramona San Diego Green Val Road Creek

CA00761 Rancho Cielito San Bernardino Trib Chino Creek

CA00825 Rancho Seco Sacramento Trib Hadselville Creek

CA00011 Rector Creek Napa Rector Creek

CA00837 Redbank Fresno Redbank Creek

CA00223 Robert A Skinner Riverside Tucalota Creek

CA00485 Roberts Modoc Trib Pit River

CA00262 Rodden Lake Stanislaus Lesnini Creek




CA10202 Salinas San Luis Obispo Salinas River

CA00620 Salt Springs Valley Calaveras Rock Creek

CA00129 San Andreas San Mateo Trib San Mateo Creek

CA00813 San Antonio Monterey San Antonio River

CA00906 San Dieguito San Diego Trib Escondido Creek

CA00200 San Gabriel Los Angeles San Gabriel River

CA10323 San Justo San Benito Offstream

CA00841 San Lorenzo Creek (Don

Castro) Alameda San Lorenzo Creek

CA00166 San Pablo Contra Costa San Pablo Creek

CA00113 San Vicente San Diego San Vicente Creek

CA00854 Sand Canyon Orange Sand Canyon

CA10024 Santa Fe Los Angeles San Gabriel River

141

CA00298 Santiago Creek Orange Santiago Creek

CA00563 Scout Lake Mendocino Trib Berry Creek

CA00669 Searsville San Mateo Corte Madera Creek

CA10025 Sepulveda Los Angeles Los Angeles River

CA10324 Seven Oaks San Bernardino Santa Ana River

CA00705 Sierra Vista Madera Chowchilla River

CA01083 Soulajule Marin Arroyo Sausal

CA00957 Spooner Lassen Trib Ash Creek

CA10192 Stampede Sierra Little Truckee River

CA10113 Success Tulare Tule River

CA00873 Sulphur Creek Orange Sulphur Creek

CA00800 Sycamore Riverside Sycamore Canyon

CA01266 Sycamore Canyon Ventura Sycamore Can

CA00729 Tejon Storage 2 Kern Trib Tejon Creek

CA00888 Terminal San Luis Obispo Trib Arroyo Grande

CA10114 Terminus (Lake Kaweah) Tulare Kaweah River

CA00084 Tinemaha Inyo Owens River

CA01115 Top Cat Tehama Trib Brannin Creek

CA01123 Trampas Canyon Orange Trampas Canyon

CA10196 Trinity Trinity Trinity River

CA00956 Tule Lake (Moon Lake) Lassen Cedar Creek

CA00905 Turner San Diego Moosa Canyon

CA10308 Twin Lakes Mono Mammoth Creek

CA10197 Twitchell San Luis Obispo Cuyama River

CA01145 Upper Oso Orange Oso Creek

CA00770 Vail Riverside Temecula Creek

CA0029 Vasona Percolating Santa Clara Los Gatos Creek

CA00750 Veeh Orange Trib San Diego Creek

CA00829 Villa Park Orange Santiago Creek

CA01314 Wallace Calaveras Trib Bear Creek

CA10303 Warm Springs Sonoma Dry Creek

CA00300 West Valley Modoc West Valley Creek

CA00904 Westlake Reservoir Los Angeles Tree Springs Creek

CA00029 Whale Rock San Luis Obispo Old Creek

CA10027 Whittier Narrows Dam Los Angeles San Gabriel River

CA00586 William, Lake Napa Trib Milliken Creek

CA00850 Wood Ranch Ventura Trib Arroyo Simi

CA00285 Woodbridge Div San Joaquin Mokelumne River

142

CA00796 Woodcrest Riverside Woodcrest Creek

CA00276 Woodward Stanislaus Simmons Creek

ompliance with alifornia ish and amedam, assessed at usgs gage #11118000..... 83 figure 33. boles...

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