Mammoth Ground Water Extraction Project

1
Mammoth Ground Water Extraction Project

• Andrew Breibart Robin Cathcart
• Karin Didriksen Lauren Everett
• Dr. John Melack

2
Research Question

• Can the Mammoth Community Water District (MCWD)
  and Mammoth Mountain Ski Area (MMSA) rely on the
  Dry Creek Watershed to be a sustainable water
  source and provide annually the 3,000 acre-feet
  they wish to extract?

3
Importance of Research

• Local Significance
• Water shortage due to an increase in economic
  development
• Broader Significance
• Competition for limited water resources between
  previous resource allocation and increased
  development.

4
Dry Creek Location
5
Dry Creek Watershed
6
? S P ET- CUR ?

• ? S Ground Water Storage
• P Precipitation Snow Water Equivalent (SWE)
  and Rain
• ET Evapotranspiration
• CU Current Use
• R Runoff
• E Error

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Precipitation

• SWE (October 1-April 1)
• SWE amount of water stored in the snow pack.
• Calculated by the depth of snow times the density
  of snow.
• measurement methods snow pillow, Mt.
  Rose-transect sampler, and Snow Pit.
• SWE analysis 7 hydrologic units

• Rain (April 1-Sept. 1)
• There are no rain gages within the basin
• Lake Mary Rain Gage (9000 ft.), since 1946
• USFS weighing bucket 7840 ft. (2390m), since 1982
• UC SNARL Weighing Bucket 7400 ft. (2256 m)
• Basin Division into 2 hydrologic units .

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SWE Zone Delineation

• 7 zones for SWE
• Each zone contains at least one SWE field
  measurement
• Similar aspect
• Similar Elevations

9
SWE Zones
10
Rainfall Zones
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Runoff and Evaporation

• Intermittent stream with flow due to snowmelt,
  springs and storm flow
• Closed Basin, although flow has entered the Owens
  River in 1969 and 1983.
• Evaporation may be modeled using Complementary
  Relationship Areal Evapotranspiration Model
  (CRAE)
• Air temperature, dew-point, daily cloud cover
• Average annual evaporative loss is 36
  ( Literature)

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Ground Water?

• Ground water storage is determined by the excess
  amount from the water budget
• Simple model of the aquifer using Visual Modflow
• Determine the interrelationship of the 5 wells
• Run a multiple drought year simulation to
  determine potential changes in hydraulic head

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MCWD Wells
14
Groundwater Flow
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1992 Water Balance Analysis

• 3 Hydrologic Units of SWE
• SWE 10,233 ac.-ft.
• Rain 2,083 ac.-ft.
• E 3,695 ac.-ft.
• CU 421 ac.-ft.
• ? S 8,200 ac.-ft.

• 7 Hydrologic Units of SWE
• SWE27,577 ac.-ft.
• Rain 3,209 ac.-ft.
• E 9,236 ac.-ft.
• CU 421 ac.-ft.
• ? S 21,129

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Water Rights Policy

• California Groundwater Law
• Percolating Waters
• Reasonableness
• Extraction from Federal Lands
• Inyo National Forest
• FONSI, MOA, BMPs
• Regulating Bodies
• SWRCB
• CRWQCB - Lahontan Region

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Stakeholder Concerns
John Arcularius
Tim Alpers
MCWD
MMSA
Mono County
Inyo National Forest
Big Springs
LAWDP
Sierra Club
Department of Fish Game
CA Sport fishing Protection Alliance
Town of Mammoth Lakes
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Policy Implications

• Potential effects seen at Big Springs
• Wells may be phased into operation
• Monitoring Well
• Pumping ceased effects analyzed
• Draw down of Water Table
• Pumping ceased effects analyzed
• Effects seen at Laurel Pond
• Water chemistry and surface levels

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Expected Results

• Full report to the MCWD and MMSA, to be used as
  an independent analysis of the potential impacts.
• Possible suggested policy options
• Extract the full 3,000 acre feet of water per
  year
• Extract less than the 3,000 acre feet
• Alternate extraction due to annual variability in
  precipitation.
• No extraction
• Monitor springs and regional ground water levels

20
Acknowledgements

• MCWD
• Gary Sisson
• UCSB
• Dan Dawson
• Jeff Dozier
• Lorne G. Everett
• Arturo Keller
• Rick Kattlemann
• Hugo Loagacia
• John Melack

• MMSA
• Thom Heller
• USGS
• Mike Sorey
• Chris Farrar
• USFS
• John Borton
• Consultants
• Dan Lyster
• Sue Burak