Mammoth Groundwater Extraction Project

1
Mammoth Groundwater 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
• Possible effects on stream flows
• Broader Significance
• The Sierra Nevada snowpack is an imperative
  resource for Californias water supply and
  economy.

4
MCWD MMSA

• Project Purpose Find alternate water source
• Constrained by existing surface water rights
• MCWD needs 2,000 ac-ft
• MMSA needs 1,000 ac-ft

5
Dry Creek Location
6
Dry Creek Location
7
SWE Zone Delineation

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

8
SWE Zones
9
Well Locations
10
Ground Water Flow
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? S P E- CUR ?

• ? S Groundwater Storage
• P Precipitation Snow Water Equivalent (SWE)
  and Rain
• E Evaporation from snow surfaces and water
  bodies and transpiration
• CU Current Use 421 Acre-feet
• 264 acre feet for snowmaking
• 157 acre feet for consumptive 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.
• Most common measurement methods snow pillow,
  Mt. Rose Method, 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 hydrolgic units .

13
Rainfall Zones
14
Runoff and Evaporation

• Intermittent stream with flow due to snowmelt,
  springs and stormflow
• It flows past the wells.
• Runoff does not leave the basin, although it has
  entered the Owens River in 1969 and 1983.
• Evaporation will be modeled using Complementary
  Relationship Areal Evapotranspiration Model
  (CRAE)
• Air temperature, dew-point, daily cloud cover
• Average annual evaporative loss is 36 (
  Literature)

15
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 ac.-ft.

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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 Sportfishing Protection Alliance
Town of Mammoth Lakes
18
Policy Implications Mitigation Measures

• If effects observed at Big Springs
• Wells phased into operation
• Monitoring wells installed
• Pumping ceased effects analyzed
• If drawdown of water table observed
• Pumping ceased effects analyzed
• If effects observed at Laurel Ponds
• Water chemistry and surface elevation

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Expected Results

• Suggest policy options 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
• Extract the full 3,000 acre feet of water after
  wet years, and 1,500 acre feet of water during
  dry years
• No extraction of any water due to not enough
  water available or substantial adverse effects
  seen at Big Springs.

20
Acknowledgements

• MMSA MCWD
• Thom Heller Gary Sisson
• USGS UCSB
• Mike Sorey Dan Dawson
• Chris Farrar Jeff Dozier
• USFS Lorne G. Everett
• John Borton Arturo Keller
• Consultants Rick Kattlemann
• Dan Lyster Hugo Loagacia
• Sue Burak John Melack