Managed Aquifer Recharge Symposium Innovative Use of Existing - PowerPoint PPT Presentation

Managed Aquifer Recharge Symposium Innovative Use of Existing Facilities for Managed Recharge in the Upper Snake River Basin, Idaho David R. Tuthill, Jr., Ph.D., P.E. January 26, 2011

Outline  The physical scenario  The legal framework  A specific example of recharge  Determinations of where and how quickly managed recharge water returns to the river system  The challenge of determining who receives credit for recharged water  The path forward

Eastern Snake Plain Aquifer Estimated storage ~ 1 billion acre-feet Estimated depth ~ 4000 feet Slide from Dr. Gary Johnson U of I

Tributary Evapotranspiration Underflow Major Sources of Recharge and Precipitation Discharge Surface Irrigation Spring Discharge Slide from Dr. Gary Johnson U of I

Discharge Recharge (millions AF/yr) -8 -6 -4 -2 0 2 4 6 SW Snake Plain Aquifer Water Budget Irrigation Tributary Inflow Precipitation Stream and River Losses Canal Losses River Gains U of I Dr. Gary Johnson Slide from Pumpage Change in Storage

Slide from Dr. Gary Johnson U of I

Water Supplies are not always sufficient so junior ground water rights are in danger of being curtailed Snake River at Milner

ANNUAL RUNOFF SNAKE RIVER AT MILNER 1910-2009 8000 7000 Data supplied by Idaho Department of Water Resources 6000 5000 1000 ACFT 4000 3000 2000 1000 0 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

On average, the spill for the basin is about 1 MAF during periods of plenty – Thus, the challenge is to recharge much of this water…

Impediment  Much of the basin is overlain with tight soils  So… Use existing canals and seek areas where the overburden is reduced

Cubic feet per second 1,000 1,200 1,400 200 400 600 800 0 24-Feb 10-Mar 24-Mar 7-Apr 21-Apr 5-May 19-May 2-Jun 2010 - ESPA Recharge Diversions 16-Jun Idaho Department of Water Resources Data supplied by 30-Jun 14-Jul AFRD2 SRVID BWCC 28-Jul 11-Aug 25-Aug 8-Sep ASCC FMID SWID 22-Sep 6-Oct 20-Oct 3-Nov 17-Nov 1-Dec 15-Dec 29-Dec

Data supplied by Idaho Department of Water Resources

Ground Water Flow Systems Local Flow System (years) Intermediate Flow System (decades) Regional Flow System (centuries) Why consider conjunctive relationships between ground water and surface water?

In Idaho the appropriation doctrine is used for the delivery both surface water rights and ground water rights— “first in time is first in right”

Section 42-4201 Idaho Code  Ground Water Recharge  … The welfare of the people of the state of Idaho is dependent upon the conservation, development, augmentation and optimum use of the water resources of this state. The legislature deems it essential therefore that every effort be made to foster and encourage water projects designed to promote these objectives…

Basalt in drainage channel after the wetting front from Egin Lakes outlet

View to the northwest - panorama 1 of ponding area

Modeling and Graph prepared by Bryce Contor

Recharge Situations Situation 1 Situation 2 Examples: Eastern Snake Plain Aquifer Aquifer Storage and Recovery

Section 42-4223 Idaho Code  Contracts to Receive Benefits  … any person or entity who has acquired or is in the process of acquiring a right to appropriate water downstream from the boundaries of the district may enter into a contract with the board of directors of the aquifer recharge district for the receipt of benefits from the district. The consideration to be paid by any company, person or entity so contracting shall be as specified in the contract…

The Path Forward  Aquifer recharge is a good idea for many locations in Idaho, including the Eastern Snake Plain Aquifer  A system is needed to provide credit for recharge – government has not been able to accomplish this – perhaps the private sector can assist…  We are eager to determine what is working in other Western States

Thank You