geotechnical engineering and hydraulics report

GEOTECHNICAL ENGINEERING AND HYDRAULICS REPORT

FOR

HEMPHILL DIVERSION STRUCTURE PLACER COUNTY, CALIFORNIA

APRIL 2020

PREPARED ON BEHALF OF

NEVADA IRRIGATION DISTRICT

1036 WEST MAIN STREET

GRASS VALLEY, CALIFORNIA 95945

792 SEARLS AVENUE

NEVADA CITY, CALIFORNIA 95959

792 Searls Avenue | Nevada City, CA 95959 | www.NV5.com | Office 530.478.1305 | Fax 530.478.1019

CONSTRUCTION QUALITY ASSURANCE – INFRASTRUCTURE – ENERGY – PROGRAM MANAGEMENT – ENVIRONMENTAL

Project No. 4794.02 April 1, 2020

Tonia Herrera Nevada Irrigation District 1036 W. Main Street Grass Valley, California 95945

Reference: Hemphill Diversion Structure Placer County, California

Subject: Geotechnical Engineering and Hydraulics Report

Dear Ms. Herrera:

Holdrege & Kull, An NV5 Company (NV5) prepared this report to summarize our site investigation, hydraulic analysis, subsurface investigation, hydraulic conductivity testing, and preliminary drawings of the infiltration basin, and associated infrastructure associated with the removal of the Hemphill Diversion Structure and water conveyance system on Auburn Ravine in Placer County, California. The site investigation was performed in general accordance with our scope of work in our Proposal for Environmental and Geotechnical Investigation, Hemphill Diversion Structure dated November 14, 2016 and authorized by Kleinschmidt on December 21, 2016, and our scope of services in our Proposal for Preliminary Infiltration Beds and Pump System dated March 27, 2018 (revised April 17, 2018) and authorized by NID on May 14, 2018.

NV5 appreciates the opportunity to provide engineering services for the Hemphill Diversion Structure project. Please contact the undersigned with any questions or comments regarding this report.

Sincerely,

NV5

Chuck Kull, C.E.G. 1622, G.E. 2359 Principal Engineer

Copies: Nevada Irrigation District/ Attn: Tonia Herrera, [email protected]

F:\1 Projects\4794 Hemphill Diversion Structure\4794.02 Phase II - Infiltration Bed & Pump Station\01 Gtk & Hydro Preliminary Report\4794-02 Hemphill Diversion Structure, Gtk & Hydraulics Report.docx

Project No. 4794-02 Geotechnical Engineering and Hydraulics Report

April 1, 2020 Hemphill Diversion Structure

NV5 | Page iii

TABLE OF CONTENTS

TABLE OF CONTENTS .................................................................................................... iii

ATTACHMENTS ..............................................................................................................iv

1 INTRODUCTION ....................................................................................................... 1

1.1 PURPOSE ................................................................................................................. 2

1.2 SITE DESCRIPTION................................................................................................... 2

2 FIELD INVESTIGATION .............................................................................................. 3

2.1 SURFACE CONDITIONS ........................................................................................... 3

2.2 SUBSURFACE SOIL CONDITIONS ............................................................................. 3

3 LABORATORY AND FIELD TEST RESULTS ................................................................... 5

4 INFILTRATION BASIN ................................................................................................ 6

4.1 SELECTION OF INFILTRATION BASIN LOCATION..................................................... 6

4.2 PRELIMINARY INFILTRATION BASIN DESIGN CRITERIA .......................................... 6

4.2.1 Basin Geometry ......................................................................................... 7

4.2.2 Pore Velocities .......................................................................................... 7

4.2.3 Water Conveyance Pipe ............................................................................ 9

4.2.4 Infiltration Bed Sizing and Dimensions ..................................................... 9

4.3 CONSTRUCTION CONCERNS ................................................................................... 9

5 HYDROLOGY .......................................................................................................... 10

5.1 HYDRAULICS ......................................................................................................... 12

5.1.1 Pre-Project Conditions ............................................................................ 12

5.1.2 Post-Project Conditions .......................................................................... 20

5.2 SCOUR ................................................................................................................... 23

5.2.1 General Scour .......................................................................................... 24

5.2.2 Bed Form Scour ....................................................................................... 25

5.2.3 Low-Flow Incisement .............................................................................. 25

5.2.4 Total Scour .............................................................................................. 25

5.3 SCOUR WITH RELATIONSHIP TO INFILTRATION BED ........................................... 26

6 FUTURE WORK ....................................................................................................... 26

7 LIMITATIONS ......................................................................................................... 26



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ATTACHMENTS

FIGURES AND SHEETS

Figure 1 Location Map Figure 2 Vicinity Map Figure 3 Site Map Figure 4 Site Map Boring-Trench Sheet 1 Infiltration Bed Sheet 2 Site Plan – Option 1 Sheet 3 Site Plan – Option 2

APPENDICES

Appendix A Boring and Trench Logs Appendix B Laboratory and Field Test Results



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1 INTRODUCTION

The Hemphill diversion, located within Auburn Ravine in Placer County, California, is an approximately eight-foot high concrete structure, with an approximately 40-foot long concrete apron extending downstream. During irrigation season (mid-April through mid-October), three-foot flashboards are installed on top of the diversion structure in order to facilitate flow into the Hemphill canal, located just upstream of the Hemphill diversion along the left bank (looking downstream) of Auburn Ravine. Image 1 below illustrates the location of these features.

The Hemphill diversion and resulting reduction in velocity and sediment transport capacity has created upstream depositional areas. Immediately downstream of the concrete apron, a scour hole has formed due to the increased ability of the sediment-starved water to transport material. Slightly downstream of the scour hole, this scoured material has deposited, as the low gradient Auburn Ravine again lacks sufficient hydraulic characteristics to transport this material over time.

Image 1: Study Location Map

Hemphill diversion

dam

Hemphill canal

intake

Hemphill canal

Image 2: Looking Upstream at Auburn Ravine from the Hemphill Diversion Structure



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Ultimately, the Nevada Irrigation District (NID) intends to remove the Hemphill Diversion

Structure. Removal of the structure will induce geomorphological impacts to Auburn Ravine in the vicinity of the structure over a relatively short-term time scale until equilibrium is re-established. Additionally, without the dam and the ability to install flashboards, upstream water surface elevations will not be able to consistently provide flows to the Hemphill canal. Therefore, a means to capture and convey irrigation flows downstream must be established in this post-dam removal condition.

A previous study performed by Kleinschmidt, entitled “Hemphill Diversion Structure Alternatives Analyses” (dated May 2016) evaluated seven irrigation capture scenarios considering constructability, cost, and environmental impacts for this post-dam removal condition. That study concluded that installing an in-stream sump pit and pump system was the preferred option. This study is essentially an extension of this work in order to develop

preliminary 30 percent design documents. The intent of this report is to provide documentation which supports the preliminary design effort and outlines possible next steps.

On behalf of NID, NV5 prepared this report to summarize our investigation, calculations, site survey, hydraulic analysis, and preliminary design of an infiltration basin to convey a maximum of 15 cubic feet per second (CFS) of water from Auburn Ravine to an open ditch that runs through Turkey Creek Golf Club in Lincoln, California.

1.1 PURPOSE

The purpose of our services was to conduct a preliminary hydraulics analysis and provide a preliminary pumping system that would be used to convey water to the Hemphill canal through Turkey Creek Golf Club once the existing Hemphill Dam is removed. The use of subterrain infiltration beds would convey water from Auburn Ravine through a series of collection screens, into a large diameter manifold, and then into a pump vault where a variable speed pump would lift the water into the Hemphill canal. The challenge is to provide these flows while protecting the salmon and smolt in Auburn Ravine.

1.2 SITE DESCRIPTION

The Nevada Irrigation District (NID) Hemphill Diversion Structure has been utilized by NID dating back to 1933 when the property was purchased. The concrete diversion structure is approximately eight feet tall, and is periodically fitted with 3-foot-tall flashboards during the irrigation season (mid- April to mid-October) to increase surface water elevation upstream and direct flow into the Hemphill Canal.

The investigation area consists of an approximately 1.5-acre impoundment upstream of the diversion structure where sediment collects. The site was accessed by traveling northwest on Virginiatown Road, and then driving south approximately 400 feet along an unnamed dirt road to the investigation area. Figures 1 and 2 show approximate site location and vicinity.



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2 FIELD INVESTIGATION

We performed our field investigation on March 2017 and June through August 2019. During our field investigation, we observed the local topography, surface conditions, and performed subsurface investigations and site surveys. The following sections summarize surface and subsurface conditions observed during our field investigation.

2.1 SURFACE CONDITIONS

At the time of our investigation, the project site appeared to be undeveloped, except for the diversion structure. The site consisted of mostly vegetation, such as large trees and shrubs on nearby eroded banks north of the diversion structure. Debris from erosion of these unstable river overbanks and fallen trees was discovered throughout the project site, and a sediment

surface was encountered behind the diversion structure. Soil samples were collected in the

area of the sediment surface for hydraulic conductivity and stream scour. Our laboratory testing included grain size analysis and our field testing included a Wolman pebble count for the scour analysis.

2.2 SUBSURFACE SOIL CONDITIONS

The soil conditions described in the following paragraphs are generalized, based on our observations of soil revealed in our exploratory borings and trenches. More detailed information can be found in the boring and trench logs in Appendix A. Figure 4 shows approximate exploratory boring and trench locations.

Boring B-1 was excavated from the ground surface to a depth of approximately 40 feet below ground surface (bgs) through reddish brown, moist, silty fine sand with gravel. The silty fine sand with gravel was underlain by reddish brown, saturated, well graded gravel to a depth of approximately 20 feet bgs. Completely weathered grano-diorite was encountered, which drilled as poorly graded course sand, from approximately 20 to 40 feet bgs. Boring B-1 was terminated at 40 feet bgs. Groundwater was first met at 10 feet bgs. In Boring B-1, we performed an airlift test on an open portion from 0 to 20 feet bgs which resulted in a discharge rate greater than 60 gpm.

Boring B-2 was excavated through dark brown, damp, silty fine sand from the surface to an approximate depth of 5 feet bgs. The silty fine sand graded to dark brown, wet, low plasticity clay and silt to an approximate depth of 10 feet bgs. The silty fine sand then graded to dark

brown, saturated, silty fine sand to an approximate depth of 17 feet bgs. The saturated, silty fine sand was underlain by completely to slightly weathered, grey, wet granodiorite, which drilled as poorly graded coarse to fine sand, to the bottom of the boring. Boring B-2 was terminated at 100 feet bgs. Groundwater was first encountered at 10 feet bgs. Boring B-2 was cased with Odex Steel Casing from 0 to 65 feet bgs with a Portland cement grout seal from 0 to 22 feet bgs.



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In Boring B 2, we performed an airlift test on the open portion from 65 to 100 feet bgs which

resulted in an approximate discharge rate of 2.5 gpm. After the Odex Steel casing was perforated, we performed another airlift test from 30 to 100 feet bgs which resulted in a discharge rate less than 1 gpm. In addition, we performed a pump test which yielded a flow rate of 2½ to 60 gpm.

Sediment depths within the impoundment were estimated using a dynamic cone penetrometer (DCP) and hand level. Sediment depth measurements within the impoundment ranged from 1 to 8 feet. These measurements were used to estimate average sediment volumes within specific sections of the impoundment. The average sediment depth along the flow line of Auburn Ravine was estimated to be 1 foot, and average sediment depths for low-energy, depositional areas of the impoundment ranged from 3 to 6 feet.

Three exploratory trenches were excavated along the southwest embankment of Auburn Ravine using an excavator equipped with a 24-inch bucket. In general, the soil consisted of medium dense, silty sand with gravel to depths of 9 feet, a thin layer of fat, dark gray clay was observed at depths of 9 to 9.5 feet, which then graded into highly weathered granitic rock. Seepage and caving soil was encountered between 2.5 and 4.0 feet bgs.

We performed an additional field investigation on August 26, 2019 by drilling 3 observation wells (Borings B19-2, B19-3, and B19-4) and one pumping well (Boring B19-1) along the northeast abutment to depths up to 35 feet. The observation wells were located approximately 15 feet from the pumping well. The subsurface soil encountered generally consisted of approximately 5 to 7 feet of pale brown, dry to moist, silty fine sand underlain by reddish brown, moist to saturated, sandy silt with gravel. Completely weathered granitic rock was encountered, which drilled as poorly graded course sand, at depths of 15 feet. Groundwater was met at 10 feet bgs and 25 feet bgs in Borings B19-1 and B19-2, respectively. Borings logs for B19-1 and B19-2 can be found in Appendix A.

A pump was placed in the pumping well (B19-1) and pumped at 40 to 60 gallons/minute. The pumping well went dry after roughly 20 minutes. The pump test was terminated and our opinion was that the material that makes up the embankment soil does not have a high enough permeability to sustain an infiltration gallery. Sheet 1 shows the approximate cross-section of the geology of the northeast abutment.

Based on the depth to weathered bedrock, our opinion is that scour would be limited to the top of the granitic rock. Using the geologic sections shown in Sheet 1, we developed a conceptual plan for an infiltration gallery that would be located entirely in the weathered rock and overlain and surrounded with open graded granular rock.



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3 LABORATORY AND FIELD TEST RESULTS

We performed laboratory and field tests on selected samples collected from our subsurface investigation to determine their engineering material properties. These engineering material properties were used to develop preliminary geotechnical engineering design recommendations for structural improvements of the project site. We performed the following laboratory and field tests.

▪ Small Scale Hydraulic Conductivity Test; Constant Head (ASTM 2434) ▪ Pebble Count, Wolman Method ▪ Particle Size Distribution (ASTM D1140) ▪ Particle Size Distribution (ASTM D442)

Particle size analysis laboratory test was performed on the material excavated for environmental sediment characterization, and then additional testing was performed in July 2019 as part of our on-going analysis of the sediment characterization. Figure 3 shows sediment sampling locations from environmental sediment characterization.

During our initial sizing of the infiltration basin, we collected material that did not pass the #4 sieve and ran a small scale hydraulic conductivity test. The same sample was used to run 3 tests, and was compared to permeability results from imported coarse grain material. The results show that the average permeability of the material collected during our field investigation was approximately 10 times lower than that of the imported material. Thus, the on-site material did not appear to be suitable to use in the infiltration basin.

A Wolman Pebble count was performed in the stream channel, downstream of the Hemphill dam for our scour analysis. Testing was performed in accordance with the Wolman Pebble Count method and the results were plotted based on ASTM D442A.

Appendix B presents our laboratory and field test results.



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4 INFILTRATION BASIN

4.1 SELECTION OF INFILTRATION BASIN LOCATION

Based on our sediment depth tables performed on March 29, 2017 and shown in Table 1 below, Auburn Ravine upstream of the Hemphill Dam had a sediment load that was up to 8 feet thick.

Table 1: Sediment Depth

Location Date Sediment Depth (feet)

HD-SS-1 03/29/17 2

HD-SS-2 03/29/17 3.5

HD-SS-3 03/29/17 7

HD-SS-4 03/29/17 3.5

HD-SS-5 03/29/17 8

HD-SS-6 03/29/17 2

HD-SS-7 03/29/17 1

HD-SS-8 03/29/17 3

Note:

Measurements were approximated using a Dynamic Cone Penetrometer (DCP)

testing and hand level.

Placing the new infiltration bed upstream of the dam will require an excavation up to 16 feet deep. The infiltration basin would be approximately 2 feet below the degraded ravine bed after dam removal. Placing the infiltration basin downstream of the dam will require a reduction in shoring of approximately 7 to 8 feet. Based on our preliminary sheet pile analysis the infiltration basin below the dam would reduce shoring costs by as much as two thirds.

Based on comments provided by the California Department of Fish and Wildlife (CDFW; November 30, 2018) and National Marine Fisheries Service (NMFW; December 21, 2018), we revised our location and components of the infiltration gallery. The main changes take into account Comment 12.5.1.9 from NMFW regarding the setback from the infiltration gallery and spawning salmon, and 12.5.1.6 regarding maximum vertical interstitial maximum velocity. Our opinion is that these parameters have been met with the revised design. Other comments have been addressed also. The preliminary infiltration basin design is described below.

4.2 PRELIMINARY INFILTRATION BASIN DESIGN CRITERIA

The following sections present our preliminary structural improvement design criteria and recommendations. The recommendations address preliminary sizing of infiltration beds, conveyance pipes and erosion/scour countermeasures to implement the proposed inflow structure.



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4.2.1 Basin Geometry

The infiltration basin would consist of a 30-foot x 55-foot basin, 27 feet below the existing ground surface (near elevation 175 Mean Sea Level [MSL]) on either the north or south side of the ravine. We are proposing 2 to 3 wedge wire screens with an air burst cleaning system. These are commercially available and designed as complete packages. The wedge wire screens are estimated to be 65 feet long; however, the actually dimensions will be calculated and provided by the supplier.

The gradation of the infiltration basin would consist of 15 to 20 feet of ¾ to 1 ½-inch drainrock overlain by compacted general fill material with a separation fabric between the two materials. The screened chambers would consist of full or half barrel intake screens that are in compliance with Clean Water Act, Section 316(b) and approved by NMFS. These parameters meet or

exceed the requirements of Section 11.7, “Screen Material” as described in the Anadromous Salmonid Passage Facility Design (National Marine Fisheries Service, Northwest Region, July 2011). The discussion in section 11.7.1.3 indicates that the screen opening must not exceed 3/32 inch or 0.094 inches.

The velocity criterion for juvenile fish for intake through the infiltration bed media should be less than 0.05 ft/sec per section 12.5.1.6 of the NMFS criteria. The following section describes the intake velocity and our calculations of interstitial velocities.

4.2.2 Pore Velocities

The pumping rate and average linear pore flow velocity through the top of the diversion structure were estimated as follows: The pumping rate was computed using Darcy’s Law for flow through porous media as expressed in Equation 1 below.

𝑄 = 𝐾 𝐼 𝐴 = 𝐾 ∆𝐻

∆𝐿 𝐴 [Eq. 1]

Where:

Q = discharge rate, (L3/T) K = hydraulic conductivity or permeability, (L/T) I = hydraulic gradient (L/L) ΔH = change in total hydraulic head between two locations in space, (L)

ΔL = distance between two locations in space along which the total hydraulic head has changed by the amount of ΔH, (L) A = cross-sectional area oriented perpendicular to the direction of flow.

The permeability of the 1.5-inch clean crushed rock was conservatively estimated to be 3 centimeters per second (cm/s) which is equal to 0.098 feet per second (ft/s). The ASTM D2434 constant head permeability test results performed by NV5 on a typical clean 1.5-inch crushed rock averaged approximately 0.22 ft/s.



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The total hydraulic head difference for flow from the water table at an elevation of

approximately 190 feet MSL to the top of the diversion structure at an elevation of approximately 182 feet MSL is 8 feet. The flow distance from the water table to the top of the diversion structure is also 8 feet. Therefore, the hydraulic gradient is equal to 1.0 foot per foot.

The cross-sectional area of the diversion structure oriented perpendicular to flow is 30-feet-wide by 65-feet-long which is equivalent to an area of approximately 1,950 square feet (sf).

Using these parameters and Equation 1, NV5 estimates that the maximum flow quantity through the top of the diversion structure is approximately 191 cubic feet per second (cfs) as computed below, however, a flow quantity of 18 cfs is the demand.

𝑄 = 𝐾 ∆𝐻

∆𝐿 𝐴 = 0.098

𝑓𝑡

𝑠 𝑥

8 𝑓𝑡

8 𝑓𝑡 𝑥 (30 𝑓𝑡 𝑥 65 𝑓𝑡) = 191 𝑐𝑓𝑠

The average linear pore flow velocity of the crushed rock for flow into the top of the diversion structure is computed by Equation 2 below.

Vs = KI

n [Eq. 2]

Where:

Vs = average linear pore velocity, (L/T) K and I remain defined as for Eq. 1 n = porosity expressed as a decimal fraction (L3/L3)

NV5 conservatively estimated of the porosity of the 1.5-inch clean crushed rock to be approximately 25 percent. Using these parameters and Equation 2, NV5 estimates that the average linear pore velocity of flow through the 1.5-inch clean crushed rock to the top of the diversion structure is approximately 0.39 ft/s as computed below for maximum water withdrawal.

𝑉𝑠 = 𝐾𝐼

𝑛=

0.098 𝑓𝑡𝑠 𝑥 1

𝑓𝑡𝑓𝑡

0.25= 0.39

𝑓𝑡

𝑠

The ratio of 191 cfs to 18 cfs is 10.6 or inversely 0.094. Therefore the proposed Vs would be 0.037 ft/s which is lower than the recommended 0.05 ft/s, which is referenced in Section 12.5.1.6 of the NMFS 2011 design document prepared by NMFS dated December 21, 2018.

Additional reduction in the Vs is the lateral transfer of water from the ravine into the new gravel, which is depicted to be 25 feet wide.

The pump would consist of a Grundfos KWM.1000(8p).H high flow/low head pump installed with the manufactures guidelines.



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4.2.3 Water Conveyance Pipe

We anticipate that water will be conveyed through a 24-inch diameter HDPE or PVC pipe from the pump vault to the Hemphill Canal. Sheets 2 and 3 show options for the infiltration basin located on either the north or south side of the ravine. Option 1 shows the infiltration bed on the north side of the ravine, in which water would be pumped over the ravine to the canal. Option 2 shows power being delivered over the ravine, and the water would be pumped directly into the Hemphill Canal. Sections A and B on Sheets 2 and 3 show the conveyance pipe and headwall details.

4.2.4 Infiltration Bed Sizing and Dimensions

The area of the infiltration bed was calculated, as described in Section 4.2. The depth was

determined by the amount of head pressure calculated for the gradient and was positioned well below any potential scour. The base elevation would be near elevation 175 MSL and extend to elevation +/- 196 MSL. The upper 6 feet above the infiltration bed would be random, native soil. The infiltration bed would extend into Auburn Ravine approximately 20 to 25 feet to further reduce the interstitial velocity and add water volume to the basin.

4.3 CONSTRUCTION CONCERNS

Our primary concern from a constructability standpoint is the flowing sand and gravel that will be encountered during excavation and groundwater inflow. Based on the subsurface seepage at shallow depths that we observed during our subsurface investigation, water flowing into the excavation will create high seepage forces and flowing sand/gravel. The excavation may require shoring or sheet piling to reach the excavation depths.

We anticipate that groundwater will enter the excavation with relatively high volumes, even with solid shoring. Groundwater removal may cause a high gradient differential that could cause the seepage forces at the base of the excavation to exceed the effective stress of the soil. This would result in a “quick condition” and ultimately the instability of the base of the excavation. A detailed analysis of the seepage forces should be performed prior to excavation and shoring.

For construction purposes, we estimate that the existing ground surface can be laid back at a 1:1, horizontal:vertical (H:V), for the top 10 feet of the excavation. Sheet pile or soldier beam and lagging, temporary shoring would need to be placed to reach the proposed excavation depths.



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5 HYDROLOGY

Flows in Auburn Ravine within the study area are controlled by the Gold Hill Dam, approximately six miles upstream of the Hemphill Diversion Structure. During irrigation season, which is from approximately April 15 through October 14, three-foot tall flashboards are installed on top of the concrete portion of the structure. These flashboards serve to create a backwater condition such that water surface elevations generate enough pressure head to direct flows into the Hemphill canal.

The Hemphill canal intake is approximately 35 feet upstream of the Hemphill Dam, along the left bank (looking downstream) of Auburn Ravine. The intake structure consists of a manually operated gate, which when raised, allows water into a concrete vault before it enters a 48-inch diameter Corrugated Metal Pipe (CMP) culvert. This culvert is approximately 40 feet in length

and discharges into a small trapezoidal open channel.

NID has historically measured flow in Auburn Ravine and the Hemphill canal starting in the early 1980s during the irrigation season (April through October). Specifically, flow rates measured in Auburn Ravine at the Highway 65 bridge, approximately 4.5 miles downstream of the Hemphill Diversion Structure, started May 1, 1982 and extended through the current date. The flow rate record for the Hemphill canal is from May 1, 1981 through the current date. Flows within the canal have generally ranged between 5 and 18 cfs.

Because the Auburn Ravine measurements are downstream of the Hemphill canal, the flow measurements inherently do not account for the canal diversion. Therefore, for the purposes of this study, flow rates through the project area were a summation of flows in Auburn Ravine and the Hemphill canal at coincident time periods beginning on May 1, 1982. As seen in Image 3, total flows are generally less than 200 cfs.

Looking into these flows further, a flow duration curve was constructed from May 1, 1982 through September 4, 2018, using values strictly from the aforementioned irrigation season of April 15 through October 14. The results can be seen in Image 4 where the median flow is

approximately 80 cfs.



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Image 3: Auburn Ravine Flows Upstream Of Hemphill Canal

Image 4: Auburn Ravine Flow Duration Curve (Irrigation Season)

0

50

100

150

200

250

1/1

/19

82

6/2

4/1

98

7

12

/14

/19

92

6/6

/19

98

11

/27

/20

03

5/1

9/2

00

9

11

/9/2

01

4

Mea

n D

isch

arge

(cfs

)

Date

Project site flow estimate

0

20

40

60

80

100

120

140

160

180

200

220

0 10

20

30

40

50

60

70

80

90

100

Mea

n D

isch

arge

(cfs

)

Exceedance Percentage (%)

Auburn Ravine Flow Duration Curve



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5.1 HYDRAULICS

Hydraulic models were developed for the study area using the Army Corps of Engineers HEC-RAS software (version 5.0.5). A pre-project model was constructed in order to establish baseline conditions in Auburn Ravine. This model was subsequently modified to simulate post-project (i.e., dam removal) hydraulic parameters for use in the preliminary design of the infiltration gallery.

5.1.1 Pre-Project Conditions

A survey was performed by Giuliani & Kull-Auburn, Inc. on August 21, 2018 to develop the pre-project (i.e., existing) terrain through the study area. This survey consisted of 10 cross-sections, which extended approximately 180 feet downstream and 540 feet upstream of the Hemphill

Diversion Structure. From these cross-sections and previous survey work which was checked and verified, Giuliani and Kull-Auburn, Inc. developed a digital elevation model (DEM) of the surface which was the geometric basis of the HEC-RAS model.

The model domain is approximately coincident with the aforementioned survey limits while incorporating the Hemphill canal culvert intake and channel on the left bank of Auburn Ravine (see Image 5). The Hemphill diversion dam has been modeled using the weir equation to avoid model instabilities associated with using the St. Venant equations under rapidly varied flow conditions. Although the culvert and Hemphill canal were included in the model, flow was not allowed to enter due to the presence of a manual gate which controls the flow and whose settings were unknown at the various times of comparison. The irrigation discharge is generally small compared to the overall flow in Auburn Ravine so this was determined to be acceptable.

Image 5: HEC-RAS Model Schematic



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Important model parameters were specified as follows:

▪ Mesh spacing of 5 feet.

▪ Computation interval of 0.2/0.3 seconds.

▪ Downstream normal depth boundary conditions in Auburn Ravine using the approximate channel slope (0.0124). The downstream boundary is approximately 250 feet from the diversion structure which through sensitivity testing was confirmed to dissipate any potential errors.

▪ Sharp crested weir coefficient equal to 3.29.

▪ Full dynamic wave equations were used for the calculations.

▪ Eddy viscosity coefficient of 0.54 was specified. This is an average value over the recommended range (0.3 to 0.77) when there is moderate transversal mixing.

▪ Manning’s roughness coefficient of 0.036 using Cowan’s equation, specifically:

𝑛 = (𝑛0 + 𝑛1 + 𝑛2 + 𝑛3 + 𝑛4) × 𝑚5

Where:

n0 = 0.02 (clean, straight, sand channel) n1 = 0.003 (low bed roughness and eroded slopes) n2 = 0.003 (occasionally alternating cross-sections) n3 = 0.004 (scattered obstructions) n4 = 0.006 (small vegetation impact) m5 = 1.0 (negligible meander)

Calibration

Calibration of the model was performed using the above parameters and an assumed inflow of approximately 47 cfs. This inflow was the approximate value calculated upstream of the

Hemphill canal on September 4, 2018, which was the date of the NV5 site visit.

It was originally intended that flow within the Hemphill canal, as calculated in the model, could be used as a proxy for calibration and validation of the water surface elevations within Auburn Ravine. However, as seen in Image 6, the Hemphill canal intake is controlled by a manual gate

which creates an orifice type entrance condition into the open concrete vault. Therefore, allowing the culvert hydraulics to determine the flow in the canal and subsequently comparing this value to the measured value would not be appropriate.



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In the absence of this approach, field reconnaissance photos and observations were used for calibration. The model results using an inflow value of 46.6 cfs were similar to inundation limits seen in the field on September 4, 2018. This can be seen in Image 7 compared to Images 8 and 9.

Overtopping of the Hemphill Diversion Structure first occurs on the right side (looking downstream) due its relative lower elevation. In Image 8, inundation limits upstream of the diversion structure extend from bank to bank with depths between three and five feet. Downstream of the structure along the concrete energy dissipation pad, depths are less than

0.5 feet. Further downstream, model results show a deeper floodplain with inundation limits across the channel as shown in Image 9. Please note that the apparent areas of no inundation along the concrete energy dissipation pad in Image 7 are artifacts of how the water surface is represented in grid cells on more steeply sloped terrain.

Image 6: Hemphill Canal Intake

Hemphill diversion

dam

Hemphill canal

intake

Image 7: HEC-RAS Maximum Depth Results



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Image 8: Auburn Ravine Looking Upstream (9/4/2018)

Image 9: Auburn Ravine Looking Downstream (9/4/2018)



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Validation

Model validation was performed using a low-flow and a high-flow discharge as shown in Table 2, below.

Table 2 - Model Validation Flows

Validation Scenario

Date Discharge (cfs)

Auburn Ravine Canal Total

Low-flow 10/25/2016 21.7 0.0 21.7

Deterministic 9/4/2018 42.8 3.8 46.6

High-flow 7/10/2016 62.7 4.4 67.1

The low-flow validation event was based on measurements on October 25, 2016, which is

outside of the irrigation season, and thus, the flashboards were assumed out and there was no flow in the Hemphill canal. The hydrograph shown in Image 10 illustrates this assumption as flow passed upstream of the diversion structure without any apparent attenuation. Image 11 overlays the model inundation results on a Google Earth aerial image of the same date.

Image 10: Low-Flow Hydrograph



NV5 | Page 17

The general flow patterns are the same in the model and aerial image, and immediately upstream and downstream of the dam match very well. Upstream of the dam, the depositional areas on both the left and right side of Auburn Ravine are dry in the model, which is the condition indicated in the aerial image. However, the inundation limits do not match around the scoured outside bend of the channel. This is due to erosion which has occurred in the

approximately two years since the date of this image. Image 12 zooms in to this area using the most recent publicly available aerial imagery (February 2018), and the inundation limits are more consistent.

Image 11: Low-Flow Maximum Inundation Limits (10/25/16)

Image 12: Eroded Right Bank Comparison

Eroded right bank

compared to the

hydraulic model

results



NV5 | Page 18

The high-flow event was taken on July 10, 2016, and because it was during irrigation season the

flashboards were assumed to be in place. Similar to the low-flow event, the model inundation results were overlaid with aerial imagery on the same date and the limits appear consistent (Image 13). As expected, the increased flow rate and presence of flashboards results in a much larger floodplain.

The high-flow hydrograph shown in Image 14 illustrates the temporal distribution of flow just upstream of the Hemphill Diversion Structure. The ‘hump’ seen around 15 minutes and the subsequent low flows of approximately five cfs represents the attenuation caused by the backwater once flow contacts the dam. As upstream flow continues to arrive and hydraulic head increases, ultimately pushing water over the structure, a more free-flowing condition resumes as shown after 45 minutes.

Image 13: High-Flow Maximum Inundation Limits (7/10/16)



NV5 | Page 19

Sensitivity

Model sensitivity was performed on the calibration run by varying the downstream boundary condition slope and roughness values by +/- 10 percent, grid size by +100% and -50%, and theta value (e.g., weighting of finite difference terms). The results were quantitatively compared by looking at the depth variance downstream and upstream of the Hemphill Diversion Structure (see Table 3). When the inundation limits are compared, results are very similar for all conditions. There is no change in water surface elevation at the canal intake because the Hemphill Diversion Structure dam acts as a hydraulic control creating a backwater condition that is not heavily influenced by other factors.

Table 3: Model Sensitivity Results

Sensitivity Scenario Water Surface Elevation along

downstream left bank (ft) Water Surface Elevation at

intake (ft)

-10% BC Slope 193.57 200.67

+10% BC Slope 193.57 200.67

-10% roughness 193.55 200.67

+10% roughness 193.60 200.67

2.5' grid size 193.60 200.67

10' grid size 193.54 200.67

Theta = 1.0 193.57 200.67

Theta = 0.6 193.58 200.67

Image 14: High-Flow Hydrograph



NV5 | Page 20

5.1.2 Post-Project Conditions

Although dam removal is anticipated to occur in stages, the post-project model for the purposes of these analyses assumes complete removal of the concrete portion of the Hemphill Diversion Structure and an equilibrium condition for Auburn Ravine. Because a sediment transport model has not been prepared for this preliminary design effort, empirical equations and engineering judgement were applied to try and predict the approximate channel geometry following removal of the structure.

Five calculations were performed to predict the stable slope of Auburn Ravine through the study area following removal of the diversion structure: Auburn Ravine slope; Schoklitsh; Meyer-Peter, Muller; Lane; and Shields. These equations and calculations are presented below with results shown in Table 5. Grain size values used in these calculations (Table 4) were

obtained from the Geotechnical Engineering Report for the Hemphill Diversion Structure prepared by Holdrege and Kull (dated June 23, 2017).

Table 4: Grain Size Results for Auburn Ravine

Sample No. D50 (mm) D90 (mm)

HD-SS-1 1.2 5.5

HD-SS-2 1.2 4.5

HD-SS-3 1.6 18

HD-SS-6 3 22

HD-SS-7 2.5 22

Average 1.9 14.4

Auburn Ravine Slope:

Using the first upstream and downstream roadway crossings at Fowler Road and McBean Park Drive, respectively, and assuming a stable bed condition at those locations, the average slope along Auburn Ravine was calculated as approximately 0.0038.

It is acknowledged that this assumption assumes an equilibrium state through this reach. Additionally, characteristics present in the Hemphill Diversion Structure study reach may not be entirely indicative of this longer reach. However, because upstream controls govern flow in Auburn Ravine, it is assumed that any watershed scale changes which may drive changes through our study reach over time are somewhat mitigated.

Schoklitsh Method:

𝑆𝑙 = 𝐾𝑠 (𝑑50𝑊

𝑄)

3/4

Where:

Ks = Schoklitsh constant (0.00174) W = channel width d50 = median bed sediment diameter Q = dominant discharge



NV5 | Page 21

Meyer-Peter, Muller Method:

𝑆𝑙 =

𝐾𝑚𝑝𝑚 (𝑄𝑄𝑏

) (𝑛

𝑑901/6)

3/2

𝑑50

𝐷

Where:

Ks = MPM constant (0.19) Q/Qb = ratio of total flow to channel flow Q = dominant discharge n = Manning’s roughness value d50 = median bed sediment diameter d90 = 90% finer bed sediment diameter

D = mean depth

Lane/Shields Methods:

𝑆𝑙 =𝜏𝑐

𝛾𝑤𝐷

𝜏∗ =𝜏𝑐

(𝛾𝑠 − 𝛾𝑤)𝑑50

Where:

𝜏∗ = dimensionless shear stress τc = critical shear stress γw = specific weight of water (62.4 lbs/ft3) γs = specific weight of sediment (165 lbs/ft3) d50 = median bed sediment diameter

Table 5: Equilibrium Slope Results

Methodology Equilibrium Slope

Schoklitsh 0.00227

MPM 0.00101

Lane 0.00073

Shields 0.00033

Auburn Ravine 0.00380

Average 0.00163

Using the average of these five methods, an equilibrium slope of 0.00163 was calculated. If the Shields’ slope is removed, the resulting slope is 0.00195. Because of the approximate and empirical nature of these equations, a value of 0.002 was felt to adequately represent these results (Image 15).



NV5 | Page 22

Upon removal of the Hemphill Diversion Structure, upstream degradation of the dam

deposition material would be expected. It is anticipated that this sediment would be transported downstream and deposited. This erosion/deposition process would continue until the channel reaches an equilibrium condition (assuming all other driving and resisting forces remain equal).

Using a channel side slope of 1.5:1, H:V, 0.002 slope, and the downstream fixed channel thalweg elevation of approximately 192 feet, the existing surface was modified to generate an estimate of the post-project conditions of Auburn Ravine (Image 16). As one moves further downstream of the structure, changes to the channel form are expected to dissipate. So while it is acknowledged that the 192 foot elevation may not be fixed over time, it represents the most stable location of our model domain.

The extent of these adjustment processes, both from a profile and plan form perspective, is hard to predict and is beyond the current scope of these analyses. It is unknown at this time to what extent channel and bank protection will be implemented in this reach. Furthermore,

prediction of the final natural channel form is inherently difficult given the many driving variables. However, for this preliminary design effort, the previously discussed general assumptions were deemed appropriate. A sediment transport model, with upstream and downstream boundaries extending beyond the current limits is recommended to obtain a better understanding of the sediment transport anticipated to occur following removal of the structure.

Image 15: Approximate Auburn Ravine slopes

189

190

191

192

193

194

195

196

197

198

0 200 400 600 800 1000

Ele

vat

ion (

feet

)

Distance along centerline (feet)

Auburn Ravine Profile

Pre-project

condition

Post-projectcondition



NV5 | Page 23

It has been assumed that the infiltration basin will be placed just downstream of the existing Hemphill diversion structure adjacent to the left bank (looking downstream) of Auburn Ravine. The post-project model was run with various flows to determine the sensitivity of flow depths at this location. Those results are shown in Table 6. It should be noted that the 223 cfs

discharge represents the largest historic flow in Auburn Ravine over the entire record starting in the early 1980s and 80 cfs represents the approximate median flow during irrigation season. The final two flows, 40 cfs and 20 cfs, were included to provide additional data points.

Table 6: Post-Project Flow Depths

Flow (cfs) Depth at proposed

infiltration basin (feet)

223 1.9

80 1.0

40 0.7

20 0.4

5.2 SCOUR

Preliminary scour calculations were performed to assist in setting the depth of the infiltration bed in order to avoid exposure of the infiltration basin during a large storm event. To that end, the aforementioned high flow value 223 cfs was used to develop the hydraulic results necessary for input into the scour calculations.

Image 16: Post-project Auburn Ravine surface



NV5 | Page 24

Assuming that the post-project geometry captures the long-term aggradation/degradation

trend, estimates for general (Table 7), bed form, and low-flow incisement scour were provided to determine total scour at the infiltration bed site. As the channel adjusts towards an equilibrium state, it is estimated that downstream of the Hemphill Diversion Structure, the stream will tend to aggrade. Therefore, the long-term degradation component was set to zero for the purposes of design scour.

5.2.1 General Scour

Lacey:

𝑦𝑠 = 𝑍 × 0.47 × (𝑄

𝑓)

13

Where:

ys = Scour depth Z = Coefficient for straight reach (0.25) Q = Design discharge (223 cfs) f = Lacey’s silt factor (1.76*(D50)0.5 = 2.43)

Blench:

𝑦𝑠 = 𝑍 (𝑞𝑓

23

𝐹𝑏𝑜

13

)

Where:

ys = Scour depth Z = Coefficient for straight reach (0.6) qf = Design discharge per unit width (223/62 = 3.6 ft3/s/ft) Fbo = Blench zero bed factor (2)

USBR Mean Velocity:

𝑦𝑠 = 𝑍 × 𝑦𝑚

Where:

ys = Scour depth Z = Lacey coefficient for straight reach (0.25) ym = Average depth (1.9 ft)



NV5 | Page 25

Table 7: General Scour Summary

Equation Scour Depth (ft)

100-Year

Lacey 0.5

Blench 1.1

USBR Mean Velocity 0.5

Average 0.7

5.2.2 Bed Form Scour

In alluvial systems, bed forms are created due to the hydraulics of water flowing over moveable

material. Dunes and anti-dunes can be formed for lower regime (Froude Number less than 0.7) and upper regime hydraulics (Froude Number greater than 1.0), respectively. The low velocities of approximately three fps through the reach result in a Froude Number of approximately 0.4. Therefore, a dune formation was assumed:

Yalin (dunes):

𝑦𝑠 = 0.167 𝑦𝑚𝑎𝑥

Where:

ys = Scour depth ymas = Maximum flow depth (1.9) ys = 0.3 feet

5.2.3 Low-Flow Incisement

Low-flow incisement scour occurs in low-flow channels due to smaller discharge events or during the floodwave recession. It is typically suggested that a scour depth value of one or two feet is used for this scour component. For the purposes of this study, one foot was used.

5.2.4 Total Scour

It was determined that general scour, bed form scour, and low-flow incisement would be the components which encompass the total scour estimate at the infiltration basin. From above:

General Scour: 0.7 feet

Bed Form Scour: 0.3 feet Low-flow Incisement: 1.0 feet Total Scour: 2.0 feet

The estimated scour depth of 2.0 feet does not include a safety factor (i.e., 1.0) for these analyses. Typically, a safety factor between 1.1 and 1.5 is specified depending on various factors, such as level of risk associated with failure consequences, uncertainty of methods used, etc.



NV5 | Page 26

5.3 SCOUR WITH RELATIONSHIP TO INFILTRATION BED

Given the estimated depth of scour to be 2.0 feet and the base elevation of the proposed Infiltration bed to be elevation 175.0, we elected to install the top of the bed at elevation 189.0 in the channel and 197.0 at the top of the gravel layer in the abutment. We anticipate that the permeability of any aggregated material from the stream channel would be similar to the material that we tested in 2017. Therefore, the footprint of the infiltration bed appears to be adequately sized. Scour that occurs below elevation 189.0 would expose the gravel in the channel. The base elevation of 175 would provide an adequate factor of safety for the infiltration bed. The boring logs revealed weathered granitic rock at a depth of 187.0 which conforms well with the calculated scour depths. Our opinion is that the weathered granitic rock will determine the grade control.

6 FUTURE WORK

Future work to consider is listed below. Some of this work is currently in progress. We should also consider having BH look at the scour and provide bank protection.

▪ Complete topographic update and extension of upstream and downstream limits to support a sediment transport model.

▪ Sediment transport model to more accurately predict how the channel may change over time.

▪ Complete mass conservation model.

▪ Bank protection design, around the removed structure and particularly upstream of the structure on the right bank (looking downstream).

▪ Examine impact on Auburn Ravine from staged removal of the Hemphill Diversion Structure.

▪ A more detailed analysis of the backwash and air diffusion pipes and pumps should be analyzed to determine sizing and backwash components. The supplier of the screens and backwash system should be able to assist in design.

▪ A constructability review should be performed to determine power needs and the development of PS&E.

7 LIMITATIONS

The following limitations apply to the findings, conclusions and recommendations presented in this report:

1. Our professional services were performed consistent with the generally accepted engineering principles and practices employed in northern California. No warranty is expressed or implied.



NV5 | Page 27

2. These services were performed consistent with our agreement with our client. We are not

responsible for the impacts of any changes in environmental standards, practices, or regulations subsequent to performance of our services. We do not warrant the accuracy of information supplied by others, or the use of segregated portions of this report. This report is solely for the use of our client unless noted otherwise. Any reliance on this report by a third party is at the party's sole risk.

3. If changes are made to the nature or design of the project as described in this report, then the conclusions and recommendations presented in this report should be considered invalid. Only our firm can determine the validity of the conclusions and recommendations presented in this report. Therefore, we should be retained to review all project changes and prepare written responses with regards to their impacts on our conclusions and recommendations. However, we may require additional fieldwork, laboratory testing, and analysis to develop any modifications to our recommendations. Costs to review project

changes and perform additional fieldwork, laboratory testing, and analysis necessary to modify our recommendations are beyond the scope of services presented in this report. Any additional work will be performed only after receipt of an approved scope of services, budget, and written authorization to proceed.

4. The analyses, conclusions and recommendations presented in this report are based on site conditions as they existed at the time we performed our surface and subsurface field investigations. Therefore, if the subsurface conditions encountered during construction are different than those described in this report, then we should be notified immediately so that we can review these differences and, if necessary, modify our recommendations.

5. Our geotechnical investigation scope of services did include evaluating the project site for

the presence of hazardous materials other than the Sediment Characterization Report we prepared in June 2017. Based on aerial photographs, the site has been used as a diversion structure. Although we did not observe evidence of hazardous materials within the proposed project site at the time of our field investigation, all project personnel should be careful and take the necessary precautions should hazardous materials be encountered during construction.

6. The findings of this report are valid as of the present date. However, changes in the conditions of the property can occur with the passage of time. The changes may be due to natural processes or to the works of man, on the project site or adjacent properties. In addition, changes in applicable or appropriate standards can occur, whether they result from legislation or the broadening of knowledge. Therefore, the recommendations

presented in this report should not be relied upon after a period of two years from the issue date without our review.

FIGURES AND SHEETS

Figure 1 Location Map

Figure 2 Vicinity Map

Figure 3 Site Map

Figure 4 Site Map Boring-Trench

Sheet 1 Infiltration Bed

Sheet 2 Site Plan – Option 1

Sheet 3 Site Plan – Option 2

210

200

en

:::;

w �0

� > w _w __

180

170

COMPACTED GENERAL ENGINEERED FILL

COMPACTED ENGINEERED PERMEABLE CRUSHED ROCK FILL

SURFACE ARMORED WITH HEAVY ON-SITE RIP-RAP ROCK

CREEK BOTTOM AND SURFACE WAJERELEVATION 190 FEETMSL

o�o0o

o 0 o 0 o 0 �

210

200

190

180

NATIVE ROCK 170

EXCAVATED

en

:::;

w w � 0

� > w w

INFILTRATION GALLERY (30-FEET-65- FEET-LONG BY 7-FEET-HIGH WI SURFACE AT APPROXIMATELY ELE

182 FE CHANNEL BOTTOM AND EMBANKMENT SURFACE

1-------30.0--------.- 10.

PUMP STATION WITH WET WELL, PUMP CONTROLS, SUBMERSIBLE PUMP TO BE

CONNECTED TO INFILTRATION GALLERY.

Notes: 1. ALL FEATURES AND DIMENSIONS SHOWN ON THIS FIGURE ARE APPROXIMATE

AND ARE PROVIDED FOR GENERAL CONCEPT ILLUSTRATION PURPOSES.

2. WIDTH OF RAVINE IS VARIABLE OVER TIME, DESIGN ASSUMES EXISTING ROCK

ELEVATION AS CONTROL DUE TO VARIABLE DEPTH OF WATER.

� MINIMUM DISTAN:E BETWEEN CHANNEL EMBANKMENT TOP AND INFILTRATION GALLERY

SCALES: HORIZONTAL= VERTICAL

NVS 792 Searls Avenue

Nevada City, California

PH: 530-478-1305 FX: 530-478-1019

CROSS-SECTION A-A' DIVERSION STRUCTURE CONCEPT

Nevada Irrigation District

Hemphill Diversion Structure Lincoln, Placer County, California

20 Feet

1 Inch

0 20

0

DRAWN BY: OMO

CHECKED BY: CRK

PROJ. NO.: 4794.00

DATE: 03-05-2020

40

SHEET NO.:

1

APPENDIX A Boring and Trench Logs

Project No.: Task:

Drill Rig Type:

Grap

hic L

og

Ground Water Information

Date

EXPLORATORY BORING LOG

Project Name:

Location:

Total Depth (Ft.):Boring Dia. (In.):

Driller:

Logged By:

Backfill or Well Design:

Hammer Type:Drilling Method:

Drilling Cmpny:

And

Sym

bol

Sam

ple I

nter

val

(TSF

)Po

cket

Pen

etro

met

er

(Ft.)

Dept

h B.

G.S.

Sam

ple N

o.

Sam

pler

Typ

ean

d/or

Drilli

ng M

etho

d

(Ft./

Ft.)

Sam

ple R

ecov

ery

(Blo

ws / 6

-inch

)Un

corre

cted

Blo

w Co

unts

1Sheet: Of

Boring No.

Depth (Ft.)Time (24 Hour)

(HH:

MM)

24 H

our C

lock

Tim

e

SOIL: USCS Symbol; Name; Particle Size Gradation %; Munsel Color; Density/Consistency; Moisture; Odor; Organics; Cementation; Texture; Refuse; Etc.ROCK: Unit Name; Lithology; Munsel Color; Cementation; Weathering; Competency; Bedding/Foliation; Fracture/Joint Spacing & Roughness; RQD; Moisture.

Soil And/Or Rock Material Descriptions

B19-11

NOTES:

140 Pound Auto Trip Hammer

Janina S. Smith

12.0 OD

Hemphill Diversion Structure Pumps Tests

Auburn Ravine Dam, Lincoln, California

Daniel Vonsterw

Woodward Drilling

21.5

Truck-Mounted Mobile B-57

4794.02

10.09:55

8-26-19

8-26-19

8-26-19

Hollow Stem Auger (HSA)

Start Date:

Finish Date:

48 BELLARMINE COURT, SUITE 40, CHICO, CA., 95928

PHONE: 530-894-2487, FAX: 530-894-2437

Estimated Ground SurfaceElevation (Ft. AMSL):

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

0SPT9:00

SPT

HSA

HSA

HSA

SPT

SPT

1684

(ML) SANDY SILT, Fld. Est.: 60% Low Plastic Clay-Silt Fines, 30% Fine Sand,and 10% Gravel; Reddish Brown (5YR 4/3); Loose; Wet to Saturated.

SPT - Standard Penetration TestHSA - Hollow Stem Augers

B1-BK1

No Recovery457

B1-BK2

10:20

B1-BK3

1198

HSA

2415

9:50

303031

(SM) SILTY FINE SAND, Fld. Est.: 70% Fine Sand and 30% Low Plastic Clay-SiltFines; Pale Brown (2.5YR 7/3); Loose to Medium Dense; Dry to Moist.

(RX) DECOMPOSED GRANITE; Gray/Black/White; Weakly Cemented;Completely Weathered; Friable; Wet.

SPT5510

21

BOH - Bottom of Hole

BOH10:50

Casing and Sand for Temporary Pump Test Well

B1-BK4

Boring Terminated at 21.5 Feet Below Ground Surface

Project No.: Task:

Drill Rig Type:

Grap

hic L

og

Ground Water Information

Date

EXPLORATORY BORING LOG

Project Name:

Location:

Total Depth (Ft.):Boring Dia. (In.):

Driller:

Logged By:

Backfill or Well Design:

Hammer Type:Drilling Method:

Drilling Cmpny:

And

Sym

bol

Sam

ple I

nter

val

(TSF

)Po

cket

Pen

etro

met

er

(Ft.)

Dept

h B.

G.S.

Sam

ple N

o.

Sam

pler

Typ

ean

d/or

Drilli

ng M

etho

d

(Ft./

Ft.)

Sam

ple R

ecov

ery

(Blo

ws / 6

-inch

)Un

corre

cted

Blo

w Co

unts

2Sheet: Of

Boring No.

Depth (Ft.)Time (24 Hour)

(HH:

MM)

24 H

our C

lock

Tim

e

SOIL: USCS Symbol; Name; Particle Size Gradation %; Munsel Color; Density/Consistency; Moisture; Odor; Organics; Cementation; Texture; Refuse; Etc.ROCK: Unit Name; Lithology; Munsel Color; Cementation; Weathering; Competency; Bedding/Foliation; Fracture/Joint Spacing & Roughness; RQD; Moisture.

Soil And/Or Rock Material Descriptions

B19-12

NOTES:

140 Pound Auto Trip Hammer

Janina S. Smith

8.0 OD

Hemphill Diversion Structure Pumps Tests

Auburn Ravine Dam, Lincoln, California

Daniel Vonsterw

Woodward Drilling

36.5

Truck-Mounted Mobile B-57

4794.02

25.012:25

8-26-19

8-26-19

8-26-19

Hollow Stem Auger (HSA)

Casing and Sand for Temporary Pump Test Well

Start Date:

Finish Date:

48 BELLARMINE COURT, SUITE 40, CHICO, CA., 95928

PHONE: 530-894-2487, FAX: 530-894-2437

Estimated Ground SurfaceElevation (Ft. AMSL):

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

20SPT12:15

SPT

HSA

HSA

H

H

50/3"

SPT - Standard Penetration TestHSA - Hollow Stem Augers

B2-BK3

50/5" B2-BK4

344

HSA

56

BOH - Bottom of Hole

BOH

[Becomes Saturated]

12:45 6

B2-BK4

12:25

Boring Terminated at 36.5 Feet Below Ground Surface

(RX) DECOMPOSED GRANITE; Gray/Black/White; Weakly Cemented;Completely Weathered; Friable; Moist.

H - Auto Trip Hammer

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APPENDIX B Laboratory and Field Test Results

DSA File #:

DSA Appl #:

Project No.: 4794.02 Project Name: Date: 7/17/2019

Sample No.: B1 Boring/Trench: 0-1' Depth, (ft.): Tested By: SLN

Description: Checked By: MLHSample Location: Lab. No.: 15-19-239

Moisture Content Data: Total Material Sample Data:Pan ID CTP Pan ID 0Pan Weight 408.70 (gm) Pan Weight 0.00 (gm)Wet Soil + Pan 3,539.80 (gm) Wet Soil + Pan Wt. 8,899.50 (gm)Dry Soil + Pan 3,502.78 (gm) Wet Weight 8,899.50 (gm)Water Weight 37.02 (gm) Dry Weight 8,794.28 (gm)Dry Soil Weight 3,094.08 (gm) Dry Wt.> #200 Sieve & Pan 8,775.50 (gm)Moisture Content 1.2 (%) 8,775.50

Total Percent <#200 Sieve 0.21 (%)

PARTICLE SIZE DISTRIBUTIONASTM D1140

Dark Yellowish Brown (10YR 3/6) Gravel with Sand

CQA – INFRASTRUCTURE – ENERGY – PROGRAM MANAGEMENT – ENVIRONMENTAL


Hemp hill

Dry Wt.> #200 Sieve

passing0%

retained100%

Percent Passing/Retained# 200 Sieve

Sieve B-3.xls200 wash

DSA File #:

DSA Appl #:


Sample No.: B2 Boring/Trench: - Depth, (ft.): 0-1 Tested By: SLN

Description: Checked By: MLH

Sample Location: Lab. No.: 15-19-239

Moisture Content Data: Total Material Sample Data:

Pan ID P2 Pan ID T4

Pan Weight 832.54 (gm) Pan Weight 0.00 (gm)

Wet Soil + Pan 10,230.54 (gm) Wet Soil + Pan Wt. 24,874.46 (gm)

Dry Soil + Pan 10,116.78 (gm) Wet Weight 24,874.46 (gm)

Water Weight 113.76 (gm) Dry Weight 24,573.36 (gm)

Dry Soil Weight 9,284.24 (gm) Dry Wt.> #200 Sieve & Pan 24,545.07 (gm)

Moisture Content 1.2 (%) 24,545.07





Hemp hill


Dry Wt.> #200 Sieve

passing0%

retained100%


4794.02 Lab 15-19-239200 wash (2)

DSA File #:

DSA Appl #:


Sample No.: B3 Boring/Trench: - Depth, (ft.): 0-1 Tested By: MLH




Pan ID IJ Pan ID 73











Hemp hill

Dark Yellowish Brown (10YR 3/6) Sand with Gravel

Dry Wt.> #200 Sieve

passing0%

retained100%


4794.02 Lab 15-19-239200 wash (3)

DSA File #:

DSA Appl #:


Sample No.: B4 Boring/Trench: 0-1' Depth, (ft.): Tested By: MLH




Pan ID B4 Pan ID 0











Hemp hill


Dry Wt.> #200 Sieve

passing0%

retained100%


4794.02 Lab 15-19-239200 wash (4)

DSA File #:

DSA Appl #:


Sample No.: B5 Boring/Trench: 0-1 Depth, (ft.): Tested By: SLN




Pan ID SN Pan ID 0











Hemp hill


Dry Wt.> #200 Sieve

passing1%

retained99%


4794.02 Lab 15-19-239200 wash (5)

Holdrege-Kull

Coarse Grain Material PermeabilityASTM D2434

Project No.: 4794-01 Project Name: Hemphill Diversion Structure Tested By: JHA

Boring/Trench No.: NA Sample No.: 3/8" Import Smpl. Depth (ft): NA Date Tested: 6/5/2017

Sample Description (USCS; Munsel Color): Checked By: BJB

Permeameter Dim.: Diameter= 0.843 ft Area = 518.5 cm^2

Run No. Time Volume Discharge L h1 h2 H I P

(sec) (min) (gal) (ml) (gpm) (ml/s) (cm) (cm) (cm) (cm) (cm/cm) (cm/s)

4 30 0.50 10.50 39749.6 21.0 1325 25.40 52.07 46.99 5.08 0.20 1.28E+01

4 30 0.50 10.40 39371.0 20.8 1312 25.40 52.07 46.99 5.08 0.20 1.27E+01

4 30 0.50 10.30 38992.4 20.6 1300 25.40 52.07 46.99 5.08 0.20 1.25E+01

4 30 0.50 10.30 38992.4 20.6 1300 25.40 52.07 46.99 5.08 0.20 1.25E+01

4 30 0.50 10.40 39371.0 20.8 1312 25.40 52.07 46.99 5.08 0.20 1.27E+01

4 30 0.50 10.20 38613.9 20.4 1287 25.40 52.07 46.99 5.08 0.20 1.24E+01

Average = 1.26E+01

h1

h2

H

L

D

4794-01 lab 15-17-132a permeability testing.xls 6/14/2017

Holdrege-Kull


Project No.: 4794-01 Project Name: Hemphill Tested By: JHA

Boring/Trench No.: Sample No.: Smpl. Depth (ft): Date Tested: 5/26/2017

Sample Description (USCS; Munsel Color): Checked By:




2 30 0.50 0.40 1495.3 0.8 50 8.26 48.10 45.72 2.38 0.29 3.33E-01

2 2 0.03 0.36 1359.1 10.8 680 8.26 48.10 45.72 2.38 0.29 4.55E+00

2 29 0.48 0.36 1359.1 0.7 47 8.26 48.10 45.72 2.38 0.29 3.14E-01

2 60 1.00 0.72 2721.9 0.7 45 8.26 48.10 45.72 2.38 0.29 3.04E-01

2 141 2.35 2.46 9297.6 1.0 66 8.26 48.10 45.72 2.38 0.29 4.41E-01

Average = 1.19E+00

h1

h2

H

L

D


Holdrege-Kull


Project No.: 4794-01 Project Name: Hemphill Tested By: JHA

Boring/Trench No.: Sample No.: Smpl. Depth (ft): Date Tested: 5/26/2017





3 51 0.85 0.64 2403.9 0.7 47 8.26 48.10 45.72 2.38 0.29 3.15E-01

3 50 0.83 0.60 2267.6 0.7 45 8.26 48.10 45.72 2.38 0.29 3.04E-01

3 49 0.82 0.60 2267.6 0.7 46 8.26 48.10 45.72 2.38 0.29 3.10E-01

3 60 1.00 0.72 2721.5 0.7 45 8.26 48.10 45.72 2.38 0.29 3.04E-01

3 429 7.15 2.70 10221.3 0.4 24 8.26 48.10 45.72 2.38 0.29 1.59E-01

Average = 2.78E-01

h1

h2

H

L

D


Holdrege-Kull








5 30 0.50 26.70 101077.5 53.4 3369 25.40 83.19 46.99 36.20 1.43 4.56E+00

5 30 0.50 26.80 101456.1 53.6 3382 25.40 83.19 46.99 36.20 1.43 4.58E+00

5 30 0.50 27.00 102213.2 54.0 3407 25.40 83.19 46.99 36.20 1.43 4.61E+00

5 30 0.50 27.00 102213.2 54.0 3407 25.40 83.19 46.99 36.20 1.43 4.61E+00

5 30 0.50 26.90 101834.6 53.8 3394 25.40 83.19 46.99 36.20 1.43 4.59E+00

5 30 0.50 27.00 102213.2 54.0 3407 25.40 83.19 46.99 36.20 1.43 4.61E+00

Average = 4.59E+00

h1

h2

H

L

D


Holdrege-Kull








6 60 1.00 25.10 95020.4 25.1 1584 25.40 61.60 46.99 14.61 0.58 5.31E+00

6 60 1.00 25.20 95399.0 25.2 1590 25.40 61.60 46.99 14.61 0.58 5.33E+00

6 60 1.00 24.70 93506.2 24.7 1558 25.40 61.60 46.99 14.61 0.58 5.23E+00

6 60 1.00 23.70 89720.5 23.7 1495 25.40 61.60 46.99 14.61 0.58 5.02E+00

6 60 1.00 23.20 87827.7 23.2 1464 25.40 61.60 46.99 14.61 0.58 4.91E+00

6 60 1.00 24.00 90856.2 24.0 1514 25.40 61.60 46.99 14.61 0.58 5.08E+00

Average = 5.15E+00

h1

h2

H

L

D


Holdrege-Kull




Sample Description (USCS; Munsel Color): Checked By: BJB




4 30 0.50 10.50 39749.6 21.0 1325 25.40 52.07 46.99 5.08 0.20 1.28E+01

4 30 0.50 10.40 39371.0 20.8 1312 25.40 52.07 46.99 5.08 0.20 1.27E+01

4 30 0.50 10.30 38992.4 20.6 1300 25.40 52.07 46.99 5.08 0.20 1.25E+01

4 30 0.50 10.30 38992.4 20.6 1300 25.40 52.07 46.99 5.08 0.20 1.25E+01

4 30 0.50 10.40 39371.0 20.8 1312 25.40 52.07 46.99 5.08 0.20 1.27E+01

4 30 0.50 10.20 38613.9 20.4 1287 25.40 52.07 46.99 5.08 0.20 1.24E+01

Average = 1.26E+01

h1

h2

H

L

D


Holdrege-Kull



Boring/Trench No.: NA Sample No.: 1.5" Import Smpl. Depth (ft): NA Date Tested: 6/5/2017





8 30 0.50 25.50 96534.7 51.0 3218 25.40 80.01 46.99 33.02 1.30 4.77E+00

8 30 0.50 25.90 98049.0 51.8 3268 25.40 80.01 46.99 33.02 1.30 4.85E+00

8 30 0.50 25.80 97670.4 51.6 3256 25.40 80.01 46.99 33.02 1.30 4.83E+00

8 30 0.50 26.00 98427.5 52.0 3281 25.40 80.01 46.99 33.02 1.30 4.87E+00

8 30 0.50 26.00 98427.5 52.0 3281 25.40 80.01 46.99 33.02 1.30 4.87E+00

Average = 4.84E+00

h1

h2

H

L

D

4794-01 1.5 inch.xls 6/14/2017

Holdrege-Kull








9 60 1.00 34.20 129470.1 34.2 2158 25.40 63.50 46.99 16.51 0.65 6.40E+00

9 60 1.00 34.50 130605.8 34.5 2177 25.40 63.50 46.99 16.51 0.65 6.46E+00

9 60 1.00 34.50 130605.8 34.5 2177 25.40 63.50 46.99 16.51 0.65 6.46E+00

9 60 1.00 35.00 132498.6 35.0 2208 25.40 63.50 46.99 16.51 0.65 6.55E+00

9 60 1.00 35.30 133634.3 35.3 2227 25.40 63.50 46.99 16.51 0.65 6.61E+00

Average = 6.50E+00

h1

h2

H

L

D

4794-01 1.5 inch.xls 6/14/2017

Holdrege-Kull








7 60 1.00 22.20 84042.0 22.2 1401 25.40 54.61 46.99 7.62 0.30 9.00E+00

7 60 1.00 22.10 83663.4 22.1 1394 25.40 54.61 46.99 7.62 0.30 8.96E+00

7 60 1.00 23.70 89720.5 23.7 1495 25.40 54.61 46.99 7.62 0.30 9.61E+00

7 60 1.00 23.80 90099.1 23.8 1502 25.40 54.61 46.99 7.62 0.30 9.65E+00

7 60 1.00 22.90 86692.0 22.9 1445 25.40 54.61 46.99 7.62 0.30 9.29E+00

7 60 1.00 22.40 84799.1 22.4 1413 25.40 54.61 46.99 7.62 0.30 9.09E+00

Average = 9.27E+00

h1

h2

H

L

D

4794-01 1.5 inch.xls 6/14/2017

4794-01 Lab 15-17-082.xlsSieve

Particle Size DistributionASTM D422

Project No.: 4794-01 Project Name: Date: 4/7/2017

Sample No.: HD-SS-1 Boring/Trench: - Depth, (ft.): - Tested By: MLH


Particle Diameter Dry Weight on Sieve PercentInches Millimeter Retained Accumulated Passing Passing

On Sieve On Sieve Sieve(in.) (mm) (gm) (gm) (gm) (%)

6.0000 152.4 0.00 0.0 4,024.3 100.03.0000 76.2 0.00 0.0 4,024.3 100.02.0000 50.8 0.00 0.0 4,024.3 100.01.5000 38.1 0.00 0.0 4,024.3 100.01.0000 25.4 0.00 0.0 4,024.3 100.00.7500 19.1 12.80 12.8 4,011.5 99.70.5000 12.7 35.50 48.3 3,976.0 98.80.3750 9.5 36.00 84.3 3,940.0 97.90.1870 4.7500 408.90 493.2 3,531.1 87.70.0787 2.0000 757.68 1,250.9 2,773.4 68.90.0335 0.8500 1,106.74 2,357.6 1,666.7 41.40.0167 0.4250 933.61 3,291.2 733.1 18.20.0098 0.2500 538.94 3,830.2 194.1 4.80.0059 0.1500 156.38 3,986.5 37.7 0.90.0030 0.0750 33.51 4,020.1 4.2 0.1

Cc = 0.76

Cu = 4.62

Strong Brown (7.5YR 4/6) Poorly Graded Sand0

Sieve Size

(U.S. Standard)

Hemphill

1.0 Inch3/4 Inch1/2 Inch3/8 Inch

6 Inch3 Inch2 Inch

1.5 Inch

#4#10

HOLDREGE & KULL(530) 478-1305 - Fax (530) 478-1019 - 792 Searls Ave.- Nevada City, CA 95959 - A California Corporation

#20#40#60#100#200

Hydr

omet

er

0.010.020.030.040.050.060.070.080.090.0

100.0

0.0010.0100.1001.00010.000100.0001,000.000

Perce

nt Pa

ssing

(%)

Particle Size (mm)

Particle Size Gradation

Clay Silt Fine Medium Sand

Fine Cobble Boulders Coarse Gravel Coarse

4794-01 Lab 15-17-082.xlsSieve (2)







6.0000 152.4 0.00 0.0 6,205.8 100.03.0000 76.2 0.00 0.0 6,205.8 100.02.0000 50.8 0.00 0.0 6,205.8 100.01.5000 38.1 0.00 0.0 6,205.8 100.01.0000 25.4 0.00 0.0 6,205.8 100.00.7500 19.1 66.80 66.8 6,139.0 98.90.5000 12.7 112.50 179.3 6,026.5 97.10.3750 9.5 91.60 270.9 5,934.9 95.60.1870 4.7500 335.20 606.1 5,599.7 90.20.0787 2.0000 1,012.80 1,618.9 4,586.9 73.90.0335 0.8500 2,225.00 3,843.9 2,361.9 38.10.0167 0.4250 1,339.86 5,183.8 1,022.0 16.50.0098 0.2500 419.47 5,603.2 602.6 9.70.0059 0.1500 205.48 5,808.7 397.1 6.40.0030 0.0750 142.25 5,951.0 254.8 4.1

Cc = 1.19

Cu = 5.77

Dark Brown (10YR 3/3) Poorly Graded Sand0

Sieve Size

(U.S. Standard)

Hemphill


6 Inch3 Inch2 Inch

1.5 Inch

#4#10


#20#40#60#100#200

Hydr

omet

er

0.010.020.030.040.050.060.070.080.090.0

100.0

0.0010.0100.1001.00010.000100.0001,000.000

Perce

nt Pa

ssing

(%)

Particle Size (mm)




4794-01 Lab 15-17-082.xlsSieve (3)







6.0000 152.4 0.00 0.0 8,646.1 100.03.0000 76.2 0.00 0.0 8,646.1 100.02.0000 50.8 0.00 0.0 8,646.1 100.01.5000 38.1 0.00 0.0 8,646.1 100.01.0000 25.4 336.40 336.4 8,309.7 96.10.7500 19.1 377.20 713.6 7,932.5 91.70.5000 12.7 670.20 1,383.8 7,262.3 84.00.3750 9.5 355.80 1,739.6 6,906.5 79.90.1870 4.7500 990.90 2,730.5 5,915.6 68.40.0787 2.0000 1,185.44 3,915.9 4,730.2 54.70.0335 0.8500 1,260.22 5,176.2 3,470.0 40.10.0167 0.4250 1,616.59 6,792.8 1,853.4 21.40.0098 0.2500 1,125.43 7,918.2 727.9 8.40.0059 0.1500 480.08 8,398.3 247.9 2.90.0030 0.0750 146.80 8,545.1 101.1 1.2

Cc = 0.47

Cu = 10.58

Brown (7.5YR 4/3) Poorly Graded Sand with Gravel0

Sieve Size

(U.S. Standard)

Hemphill


6 Inch3 Inch2 Inch

1.5 Inch

#4#10


#20#40#60#100#200

Hydr

omet

er

0.010.020.030.040.050.060.070.080.090.0

100.0

0.0010.0100.1001.00010.000100.0001,000.000

Perce

nt Pa

ssing

(%)

Particle Size (mm)




4794-01 Lab 15-17-082.xlsSieve (6)







6.0000 152.4 0.00 0.0 9,035.1 100.03.0000 76.2 0.00 0.0 9,035.1 100.02.0000 50.8 0.00 0.0 9,035.1 100.01.5000 38.1 0.00 0.0 9,035.1 100.01.0000 25.4 548.30 548.3 8,486.8 93.90.7500 19.1 548.80 1,097.1 7,938.0 87.90.5000 12.7 993.40 2,090.5 6,944.6 76.90.3750 9.5 557.10 2,647.6 6,387.5 70.70.1870 4.7500 1,238.80 3,886.4 5,148.7 57.00.0787 2.0000 1,245.37 5,131.8 3,903.4 43.20.0335 0.8500 1,794.47 6,926.2 2,108.9 23.30.0167 0.4250 1,441.59 8,367.8 667.3 7.40.0098 0.2500 367.12 8,735.0 300.2 3.30.0059 0.1500 121.85 8,856.8 178.3 2.00.0030 0.0750 53.80 8,910.6 124.5 1.4

Cc = 0.52

Cu = 11.98

Brown (7.5YR 4/4) Poorly Graded Sand with Gravel0

Sieve Size

(U.S. Standard)

Hemphill


6 Inch3 Inch2 Inch

1.5 Inch

#4#10


#20#40#60#100#200

Hydr

omet

er

0.010.020.030.040.050.060.070.080.090.0

100.0

0.0010.0100.1001.00010.000100.0001,000.000

Perce

nt Pa

ssing

(%)

Particle Size (mm)




4794-01 Lab 15-17-082.xlsSieve (7)







6.0000 152.4 0.00 0.0 5,902.5 100.03.0000 76.2 0.00 0.0 5,902.5 100.02.0000 50.8 0.00 0.0 5,902.5 100.01.5000 38.1 0.00 0.0 5,902.5 100.01.0000 25.4 292.60 292.6 5,609.9 95.00.7500 19.1 487.30 779.9 5,122.6 86.80.5000 12.7 593.40 1,373.3 4,529.2 76.70.3750 9.5 400.80 1,774.1 4,128.4 69.90.1870 4.7500 341.30 2,115.4 3,787.1 64.20.0787 2.0000 1,010.91 3,126.3 2,776.1 47.00.0335 0.8500 712.38 3,838.7 2,063.8 35.00.0167 0.4250 698.66 4,537.4 1,365.1 23.10.0098 0.2500 752.89 5,290.2 612.2 10.40.0059 0.1500 451.23 5,741.5 161.0 2.70.0030 0.0750 99.10 5,840.6 61.9 1.0

Cc = 0.44

Cu = 15.83

Dark Brown (10YR 3/3) Poorly Graded Sand with Gravel0

Sieve Size

(U.S. Standard)

Hemphill


6 Inch3 Inch2 Inch

1.5 Inch

#4#10


#20#40#60#100#200

Hydr

omet

er

0.010.020.030.040.050.060.070.080.090.0

100.0

0.0010.0100.1001.00010.000100.0001,000.000

Perce

nt Pa

ssing

(%)

Particle Size (mm)




Project No.: 4794.02 Project Name: Date: 9/11/2018Sample No.: T1 Boring/Trench: N/A Depth, (ft.): N/A Tested By: TMKDescription: Checked By:Sample Location: See Map

Sieve Size Class Frequency(U.S. Standard) (in.) (%) Passing

18 18 100.0017 17 100.0016 16 100.0015 15 100.0014 14 100.0013 13 100.0012 12 100.0011 11 100.0010 10 100.009 9 100.008 8 100.007 7 100.006 6 100.005 5 100.004 4 100.00

3 Inch 3 100.002 Inch 2 98.00

1 5 Inch 1.5 96.001.0 Inch 1.0 88.003/4 Inch 0.75 82.001/2 Inch 0.50 68.003/8 Inch 0.375 64.00

#4 0.187 36.00#10 0.0787 22.00

D50 (in)

D84 (in)

(530) 478-1305 - 792 Searls Ave. Nevada City, CA 95959

Wolman Pebble CountGradation Curve

Hemphill Diversion Structure

Well graded gravel with sand, cobbles, and boulders (GW)

0.281

0.833

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.0500 5005.000

Perc

ent P

assi

ng (%

)

Particle Size (in)


4794 02 Pebble Count - Copy1 xlsxT1



18 18 98.0017 17 98.0016 16 98.0015 15 98.0014 14 98.0013 13 98.0012 12 98.0011 11 98.0010 10 98.009 9 98.008 8 96.007 7 96.006 6 96.005 5 96.004 4 94.00

3 Inch 3 92.002 Inch 2 84.00


#4 0.187 30.00#10 0.0787 18.00

D50 (in)

D84 (in)





0.375

2.000

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.0500 5005.000

Perc

ent P

assi

ng (%

)

Particle Size (in)





18 18 100.0017 17 100.0016 16 100.0015 15 100.0014 14 100.0013 13 100.0012 12 100.0011 11 100.0010 10 100.009 9 100.008 8 100.007 7 100.006 6 100.005 5 100.004 4 100.00

3 Inch 3 100.002 Inch 2 100.00


#4 0.187 32.00#10 0.0787 22.00

D50 (in)

D84 (in)





0.293

0.813

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.0500 5005.000

Perc

ent P

assi

ng (%

)

Particle Size (in)



Project No.: 4794.02 Project Name: Date: 9/11/2018Sample No.: T1,T3 Boring/Trench: N/A Depth, (ft.): N/A Tested By: TMKDescription: Checked By:Sample Location: See Map


18 18 100.0017 17 100.0016 16 100.0015 15 100.0014 14 100.0013 13 100.0012 12 100.0011 11 100.0010 10 100.009 9 100.008 8 100.007 7 100.006 6 100.005 5 100.004 4 100.00

3 Inch 3 100.002 Inch 2 99.00


#4 0.187 34.00#10 0.0787 22.00

D50 (in)

D84 (in)


0.821




0.287

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.0500 5005.000

Perc

ent P

assi

ng (%

)

Particle Size (in)


4794 02 Pebble Count - Copy1 xlsxT1 T3

Project No.: 4794.02 Project Name: Date: 9/11/2018Sample No.: T1, T2, T3 Boring/Trench: N/A Depth, (ft.): N/A Tested By: TMKDescription: Checked By:Sample Location: See Map


18 18 99.3317 17 99.3316 16 99.3315 15 99.3314 14 99.3313 13 99.3312 12 99.3311 11 99.3310 10 99.339 9 99.338 8 98.677 7 98.676 6 98.675 5 98.674 4 98.00

3 Inch 3 97.332 Inch 2 94.00


#4 0.187 32.67#10 0.0787 20.67

D50 (in)

D84 (in)

0.309

1.214





0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.0500 5005.000

Perc

ent P

assi

ng (%

)

Particle Size (in)


4794 02 Pebble Count - Copy1 xlsxT1 T2 T3

Project No.: 4794.02 Project Name: Hemphill Diversion Structure Date: 9/11/2018

Sample No.: 1-150 Boring/Trench: N/A Depth, (ft.): N/A Tested By: TMK

Description: Well graded gravel with sand, cobbles, and boulders (GW) Checked By:Sample Location See Map

Wolman Pebble Count Transect Map


1T3

Project No.: 4794.02 Project Name: Hemphill Diversion Structure Date: 9/11/2018

Sample No.: 1-150 Boring/Trench: N/A Depth, (ft.): N/A Tested By: TMK

Description: Well graded gravel with sand, cobbles, and boulders (GW) Checked By:Sample Location See Map

Sample No. Size (in) Sample No. Size (in) Sample No. Size (in)1 0.38 51 0.625 101 1.8752 <2mm 52 0.25 102 0.1253 <2mm 53 1.25 103 1.254 0.125 54 1.75 104 <2mm5 <2mm 55 1.5 105 0.1256 1 56 1.625 106 <2mm7 0.125 57 <2mm 107 0.258 0.75 58 <2mm 108 0.759 0.25 59 2.125 109 0.25

10 0.25 60 1.625 110 0.87511 2.125 61 0.5 111 0.37512 <2mm 62 1.125 112 1.513 <2mm 63 0.375 113 114 0.25 64 0.125 114 0.87515 0.25 65 19.5 115 0.7516 0.125 66 0.25 116 <2mm17 <2mm 67 3.5 117 0.12518 0.375 68 <2mm 118 <2mm19 1.125 69 0.75 119 0.2520 0.125 70 0.625 120 0.2521 1.125 71 2.25 121 0.37522 0.75 72 <2mm 122 0.7523 1.75 73 2.375 123 0.524 0.375 74 <2mm 124 0.37525 0.75 75 8.25 125 0.12526 <2mm 76 1.625 126 <2mm27 0.625 77 0.125 127 0.37528 0.25 78 0.375 128 <2mm29 0.25 79 1.25 129 <2mm30 <2mm 80 0.375 130 <2mm31 0.5 81 <2mm 131 0.37532 0.25 82 0.1875 132 0.87533 0.625 83 1.125 133 0.62534 0.875 84 4.125 134 0.2535 0.375 85 <2mm 135 0.37536 0.375 86 0.125 136 0.37537 0.625 87 <2mm 137 0.538 0.125 88 1.875 138 1.12539 <2mm 89 1 139 0.62540 <2mm 90 0.125 140 0.2541 0.125 91 0.1875 141 0.12542 0.625 92 0.25 142 <2mm43 0.375 93 0.375 143 <2mm44 0.5 94 0.125 144 0.37545 1.375 95 0.25 145 0.2546 1.125 96 0.125 146 0.547 0.25 97 0.875 147 1.12548 0.875 98 1.125 148 0.62549 0.125 99 <2mm 149 <2mm50 <2mm 100 3 150 0.25

Tra

nsec

t 2

Tra

nsec

t 3

Wolman Pebble Count Data SheetT

rans

ect 1


geotechnical engineering and hydraulics report

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