Preliminary Assessment oalong the g

Deborah LS.S. Papadopul

www

of Groundwater Conditions Gila River

photo courtesy of MEI

. Hathaway, P.E.los & Associates, Inc.w.sspa.com

Study ObjectivesStudy Objectives

Compile data and h t icharacterize:

• Groundwater conditions

• Water supply

• Groundwater-surface water relationshipsrelationships

• Hydrologic conditions in the riparian groundwater zone

• Identify next steps

Within the basin fill areas f th Gil Ri B i iof the Gila River Basin in

New Mexico

Summary of Presentation

1. Hydrogeologic Data

2. Water Uses

3. Water Budget and Limitations

4. Directions for Investigationg

5. Riparian Groundwater Model, background and examples

6. Data Needs

1. Summary of Data1. Summary of Data

• Geologic SettingGeologic Setting

• Depth to groundwater, direction of groundwater gflow, long-term trends

• Aquifer properties

• Existing water uses

Within the basin fill areasWithin the basin fill areas of the Gila River Basin in New Mexico

TNC Site, photo courtesy of MEI

G l i S ttiGeologic Setting

• Bedrock

Gil G• Gila Group

• Fluvial sediments

• Channel, floodplain

• TerraceTerrace

Depth to pGroundwater, (time of drilling)

• Red, 4 – 25 ft

• Orange, 25-50 ft

• Yellow, 50-100 ft

• Green, 100-200 ft

• Blue, >200 ft,

GeneralizedGeneralized Groundwater

Elevation Contours

Contours from WRRI, 2000

S ifi Specific Capacity

Calculated for 7 wells with suitable data

Hydraulic Conductivity and Transmissivity Estimates

Hawley - Sediment properties ofHawley Sediment properties of hydrostratigraphic units:

• Alluvial aquifer, high permeability;

• Gila Group aquifers, low to moderate permeability;

• Alluvial aquifer 10 to 100 times more permeable than Gila Group

Trauger: Examination of well logsTrauger: Examination of well logs, yield, limited hydraulic tests:

• Similarly notes contrast in permeability

2. Existing(rough estimates fr( g

Irrigation, consumptive use• 5,600 ac-ft (3,500 acres, approx San

• 4,800 ac-ft (Hawley cites Wilson, ’95

Mining diversion to Tyrone• Mining, diversion to Tyrone • 5,000 ac-ft (Year 2002, DBSA)

• 6,582 ac-ft (Max, water right, DBSA)6,582 ac ft (Max, water right, DBSA)

• Domestic-stock-other non-ag: ~

• Riparian vegetation: 4 000 ac f• Riparian vegetation: 4,000 ac-f

• Municipal, Franks wellfield: 300

Need to update/confirm –

g Water Usesrom previous studies)p )

ndia; 1.6 af/a CU OSE)

5, water use from SW & GW)

))

~ 300 (Sandia)

ft (DBSA)ft (DBSA)

– 1,000 afy (Sandia, 2000-2006)

– see June ‘09 report

3. Water Budget and 3. Water Budget and Limitations

• Water budget

• Impacts of water use on stream

• Groundwater in storage

• Limits on uses

• Assume existing non-riparian uses approximately 12,000* acre-feet/year/y

• With riparian depletion, total depletion about 16,000* acre-feet/year

• Decreed water rights would ll f dd l d lallow for additional depletion,

but,

Both surface and groundwaterBoth surface and groundwater uses in the Gila Basin will impact stream flows.

* Estimates to be revised, see June ‘09 report

Groundwater in StorageGila Basin

• Alluvial aquifers: • 700,000 ac-ft estimated (DBSA), ( )

• Extraction would have rapid and equal im

• Gila Group:p• 22,435,000 ac-ft estimated (DBSA)

• Extraction would have lagged but ultiequal impact on river

Gila Basin aquifers may offer opportunities for groundwater sopportunities for groundwater sand recovery, but additional largdevelopment for water supply apunsustainable in the long-term.

e,

mpact on river

mately

storagestorage ge-scale

appears

4. Directions for 4. Directions for Investigation

• Questions of interestQ

• Recommendations

• Resources• Resources

Question: Can additional supBasin without undesired

If diversions are increased, or additional groundwater pumped, g p p ,how will hydrologic conditions in riparian zone be changed?

• River losses and gains

• Shallow groundwater conditions in channel and floodplainchannel and floodplain

• Overbank flooding and habitat

Will i t ti iti hWill river management activities havthe desired effect?

What mitigation strategies might beWhat mitigation strategies might beneeded, and will they work?

pply be provided from the Gila d impacts to the stream?

the

ave

eBIRDS Site, photo courtesy of MEI

e

Recommend

1. Prepare simple regional grinsight on regional conditions.

h ? S t l tiwhy? Support evaluation o

2. Estimate mountain front reapproach and public domain spaapproach and public domain spa

why? Improve accuracy of regional modelregional model

3. Build one or more high-resolumodels of alluvial aquifer.q

why? To understand the hsensitive to changes in diverimpacts from existing and po

dations

roundwater model to provide

f d t iof groundwater uses on river

echarge using water balance atial climate data for watershedatial climate data for watershed.

basin-wide water balance and

ution, riparian groundwater

hydrology of river zones that are rsions, and to avoid adverse otential future conditions

5. Riparian Groundwater ModpBackground and Examples

• Rationale

E l f th i• Examples from other rivers

• Potential for application to the Gila River fluvial aquiferthe Gila River fluvial aquifer

dels, ,s

RRiparian groundwater models h d l i ditiassess hydrologic conditions

in the near-river zone in a dynamic system:

• Changing river flow levels, seasonally and annually;seasonally and annually;

• Changing regional groundwater conditions;

• Changing diversion patterns;• Changing vegetation type or

extentextent.

Example: Middle Rio Grande RiparianCochiti Dam to Elephant Butte ReseCochiti Dam to Elephant Butte Rese

• 8 groundwater models covering 180 rithe near-river zonethe near river zone

1. Cochiti2. Upper Albuquerque3. Lower Albuquerque4 B l4. Belen5. Bernardo6. Socorro7. Bosque del Apache8. Fort Craig

• High resolution model cells : 250 x 125

• 4 model layers represent physical procontrol shallow groundwater condition

i /lgains/losses

n Modelservoirervoir

iver miles of

feet

ocesses thatns and river

Model Properties• MODFLOW code

• Active domain is river alluvium

• Boundary conditions from existinregional models or existing well datregional models or existing well dat

• River depth and width changes wichanging flow levels through th

i ff d l fl i dspring runoff and low flow periods

Rio Grande at Albuquerque: Measured flow vs. assigned Library flow

4,000

5,000

6,000

cfs)

Flow Modeled flow

0

1,000

2,000

3,000

Flow

(

Oct-00

Nov-00

Dec-00

Jan-0

1Feb

-01Mar-

01Apr-

01May

-01Ju

n-01

Jul-0

1

Date

ngtata

thhe

Example: Deptunder Alternate Rive

pth to Water er Flow Conditions

DEPTH TO WATER

Red = 52 – 60 ftYellow = 44 – 50 ft

fGreen = 20 – 44 ftBlue = 0 – 20 ft

Alternate VegetatiConditionsConditions

iScenario: Areas with maximum4 feet/year changed to 3 feet/y

Results:Ch i d t l• Change in groundwater elevalocalized areas

• Minimal overall change in rivMinimal overall change in rivdrain seepage

• Some reduction in water lost

on

m ET rate of year.

ti iations in

ver andver and

t to ET

Alternate Regional Gro

Low-Water Boundary Condition

Results:

• Riparian corridor is “drier” in both the late spring and mid-summer

• River seepage loss rates increase• Inflow to the drains decreases • Low regional groundwater conditions

result, which could impact:, p• maintenance of desired river flows • water delivery via the river channel

High-Water Boundary Conditio• Riparian corridor is “wetter”• River seepage losses decrease• River seepage losses decrease • Inflow to the drains increases

oundwater Conditions

n

Low Base High

.

ns

Low Base High

Four Reaches Suitable for

Gila River Riparian Groundwater Models

Example Riparian Groundwater Model

Framework, Mogollon Creek to Duck Creek

Areas of Riparian Vegetation and DepthVegetation and Depth to Water at Selected

Wells

6 Data Needs

• River seepage runs to quantify

6. Data Needs

River seepage runs to quantify reach gains/losses;

• Monitoring data from new gobservation wells in floodplain;

• Additional river cross-section elevation surveys; extend HEC hydraulic model over reach of interest.interest.

Questions?

BiBi

Questions?

rds site photo courtesy of MEIrds site, photo courtesy of MEI