1. Ground-Water Management Plan Beryl Enterprise Area August 6, 2007 Sign up sheet

2. Agenda Water Management Issues Voluntary arrangements Management plan scenarios Water Rights Safe Yield Questions / Future directions Handout www.waterrights.utah.gov

3. Evaporation Transpiration Deep Percolation / Return Flow Water Use Terms ET = Evapotranspiration

4. Definitions Consumptive Use (Irrigation) The quantity of water that is absorbed by the crop and transpired or used directly in the building of plant tissue, together with that evaporated from the cropped area. Consumptive use – effective precip = Net irrigation requirement Enterprise/Beryl Jct, Net irrigation requirement Alfalfa = 2.49 AFGrain = 1.66 AF Potatoes = 1.40 AFCorn = 1.38 AF

5. Definitions (cont’d) Depletion - That part of the withdrawal that has been evaporated, transpired, incorporated into the crops or products, consumed by man or livestock, or otherwise removed. The wellhead diversion minus return flow to the groundwater aquifer. CU + Incidental losses

6. Definitions (cont’d) Irrigation Diversion Allowance - The quantity of water required to satisfy the irrigation water requirements and taking into account conveyance and application losses. Calculated using alfalfa and flood irrigation practices. In the 71 Area the irrigation diversion allowance is 4.0 acre-feet per acre per year. Irrigation Duty (Duty)

7. Ground-Water Management Plan Objectives of a plan Limit withdrawals to safe yield Protect the physical integrity Protect water quality Principles of prior appropriation Basin hydrology Relationship surface & ground water Well spacing Well interference Other relevant factors

8. Voluntary Arrangements Subsection 4(c), 73-5-15, GW Mgt Plan Water users may agree & participate Voluntary arrangements Consultation with state engineer Any time Consistent with other law If less than all water users Does not affect the rights of others

9. Possible Scenarios Present 5 possible scenarios Only for discussion purposes Stimulate thought and debate A target to consider

10. Scenario # 1 (stepped ) Leave as is for a set period of time End of initial period (# years) Reduce diversions by set amount (%) Monitor for set period (x yrs.) Continue until safe yield reached Time Ac-Ft

11. Scenario #2 (new water) Importation of water Lake Powell Pipeline Other options Economics ?

12. Scenario #3 (steady & gradual) Immediately begin reducing diversions % reduction each year Monitor water levels and diversions Ac-Ft Time

13. Scenario #4 (crop) Reduce diversions by changing crops Adjust cropping pattern alfalfa  grain, potatoes & corn Implement over time Depletion target ( Safe yield )

14. Scenario #5 – Proposal set forth by Escalante Water Users 1 year to develop resolution Reduce the duty from 4.0 to 3.2 AF/A 3.2 AF/A average over 5 years Metering using power records Cut water use 10%, 40-years (2,500 acs) Compensation program ($10 million) 50% local & 50% state

15. Water Right Records Review and update electronic records –Sole supply –Place of use groups Certificate outstanding proofs

16. Water Right Priority

17. Water Right Depletions

18. Safe Yield The perennial safe yield is equal to the amount of groundwater that can be withdrawn from the basin over a period of time without exceeding the long-term recharge of the basin or unreasonably affecting the basin’s physical and chemical integrity.

19. Hydrologic Studies Hydrology Of The Beryl-Enterprise Area, Escalante Desert, … - Mower (1982) Ground-water conditions in Utah - Burden (2005) USGS National Information System Water Level Web Interface Consumptive Use of Irrigated Crops in Utah – Hill (1994) Acreage Surveys – Utah Division of Water Rights

20. Recharge Acre Feet Subsurface Inflow from Mountains/Streams Precipitation on Valley Floor Subsurface Inflow Return Flow from Surface Irrigation Natural Recharge 31,000 500 320 1,400 34,000

21. Recharge Where: Q recharge is the recharge to the aquifer Q consumptive is the estimated crop depletions from well withdrawals. Δ storage is the calculated change in water stored in the aquifer 5 year period from 2001 to 2005 Q recharge + Δ storage = Q consumptive

22. Recharge Where: Q recharge is the recharge to the aquifer Q consumptive is the estimated crop depletions from well withdrawals. Δ storage is the calculated change in water stored in the aquifer 5 year period from 2001 to 2005 Q recharge = Q consumptive - Δ storage

23. Method 1 - Q consumptive Well Withdrawal Estimates - USGS - 87,640 acft Consumptive Factor - HILL - 78 % Q consumptive - 68,359 acft

24. Method 2 - Q consumptive Underground Supplied Irrigation - 25,040 acres Consumptive Use - 2.49 acft/acre Q consumptive - 62,348 acft

25. Δ storage USGS Observations 2001

26. Δ storage Water Level Surface 2001

27. Δ storage Water Level Surface 2006

28. Δ storage Water Level Surface 2006

29. Δ storage Drawdown From 2001 - 2006

30. Specific Yield - Porosity Specific yield is the ratio of the volume of water drained to the total rock volume Groundwater Model

31. Δ storage Δ Storage Specific Yield Δ Volume X Δ Storage = 31,425 acft

32. Recharge Q recharge = Q consumptive - Δ storage 33,575 = 65,000 - 31,425 Safe Yield = 34,000 acre feet / year

33. Safe Yield Best Estimate = 34,000 acre feet / year How will we know we have reached safe yield? Water Levels

34. Questions ?

35. Summary Nothing is set in stone Given you several proposals to consider Allow you time to consider Review the water right records Comments – September 30 Next meeting – late fall Thank you