RANCHO CALIFORNIA WATER DISTRICT GROUNDWATER WORKSHOP. Groundwater Production History and Outlook for the Temecula Valley Groundwater Basin

Transcription

1 RANCHO CALIFORNIA WATER DISTRICT GROUNDWATER WORKSHOP by: Dennis Williams July 22,

2 Overview Geohydrology of the Rancho California Area RCWD Ground Water Management Plan Ground Water Management Tools Results of Annual Water Audit 1-Jul-14 to 30-Jun Jul-14 2

3 Upper Santa Margarita River Basin Lower Santa Margarita River Basin 3 3

4 Upper Santa Margarita River Watershed 4 22-Jul-14 4

5 Geologic Map 5 5

6 Pauba Valley Wolf Valley Temecula Gorge Murrieta Valley 6 22-Jul-14 6 and Outlook for the Temecula Valley Groundwater Upper Basin Santa Margarita River Basin

7 Aquifer Systems Stream Younger Alluvium 500 ft Pauba Aquifer Temecula Aquifer 1,000 ft 22-Jul-14 7

8 Basin Divided Into Eleven Hydrologic Subunits 22-Jul-14 8

9 Pauba Valley Hydrologic Subunit 22-Jul-14 9

10 Ground Water Management Process Planning, Implementation And Operation Necessary To Provide Safe And Reliable Ground Water Supplies 22-Jul-14 10

11 RCWD s Ground Water Management Plan Goals And Objectives Defined Tools And Resources Available Meaningful Milestones Reasonable Time Schedule California Statewide Groundwater Elevation Monitoring (CASGEM) Program Annual Water Audits 22-Jul-14 11

12 Sustainable Yield Extraction That: Does Not Exceed Recharge on Long-Term Basis Does Not Permanently Lower The Water Table To An Undesirable Level Does Not Allow Degradation Of Water Quality Does Not Create Subsidence 22-Jul-14 12

13 Sustainable Yield Example PUMPING = 200 RECHARGE = 100 STORAGE CHANGE = Long Term Pumping Greater Than Recharge Exceeds Sustainable Yield 22-Jul-14 13

14 Sustainable Yield Example PUMPING = 200 Artificial Recharge = 100 Natural Recharge = 100 STORAGE CHANGE = 0 Artificial Recharge Increases Sustainable Yield 22-Jul-14 14

15 RCWD Ground Water Management Tools Integrated Ground Water and Surface Water Model Yearly Water Audit Index Well Groups CASGEM Program Timely Measurement And Reporting Of Data SCADA, GIS Agency Agreements 22-Jul-14 15

16 CWRMA Model Update and Refinement 3D Lithologic Model Used Watershed Model (PRMS) Incorporated 16

17 400 ft Model Grid and Active/Inactive Cells 1 1 PRMS 320 MODFLOW ft Inactive Active Jul-14 17

18 Lithologic Model 5 Layers 18

19 Ground Water Model 5 Model Layers Younger Alluvium Layer 1 Pauba Fm. Layer 2 Temecula Fm. Layer 3 Temecula Fm. Layer 4 22-Jul-14 19

20 Summary of Murrieta-Temecula Updated Model The calibration of the updated model has a relative error of 7.2%, which is an improvement from the relative error of 8.8% of the original Murrieta-Temecula Ground Water Basin model, and well below the recommended error of 10%. 22-Jul-14 20

21 Daily Streamflow, cfs Summary of Murrieta-Temecula Updated Model (Cont.) 10,000 Hydrograph of Measured and Model-Calculated Daily Streamflow at the Santa Margarita River at Temecula Gorge Gaging Station - GSFLOW Calibration The updated model can simulate 1,000 Observed Model-Calculated streamflow on a daily basis which is an improvement from quarterly of the original model Results of the model calibration indicate a good match of daily measured and model-calculated streamflow in creeks within the model area Date Temecula Gorge Figure Jul-14 21

22 Summary of Murrieta-Temecula Updated Model (Cont.) The updated model has been used to evaluate impacts related to the Municipal Separate Storm Sewer System (MS4) storm drainage regulations. The updated model can be used to assist Watermaster to calculate ground water storage, evaluate return flow credits and confirm the Vail Recharge Account and Imported Water Carryover Account. The updated model can run predictive scenarios to evaluate water levels and streamflow under various management conditions. 22-Jul-14 22

23 RCWD Index Well Group Index Wells Characterize the Entire Basin

24 California Statewide Groundwater Monitoring (CASGEM) Program Goal of the CASGEM program to monitor groundwater elevations that demonstrate seasonal and long-term trends to make this information available to the public. A Monitoring Network with 20 Wells. 24

25 Annual Water Audits RCWD Conducts Yearly Water Audits (1-Jul Jun-15) Annual Meeting With RCWD Personnel (Nov 2013) Preparation Of Pumping Schedule Analysis Of Hydrographs Run Ground Water Basin Model Preparation Of Annual Report Constant Updating Throughout Year of Pumping Schedule 22-Jul-14 25

26 Monthly Production, acre-ft Ground Water Elevation, ft AMSL Water Audit Considers Short and Long Term Water Level Changes and Production - 83 Wells Analyzed 500 WELL 110 1, Land Surface 1, , , Production Recommended production for : 900 acre-ft 1,

27 Monthly Production, acre-ft Ground Water Elevation, ft AMSL Water Audit Considers Short and Long Term Water Level Changes and Production - 83 Wells Analyzed WELL , Land Surface 1, , Production Recommended production for : 700 acre-ft

28 Water Audit Considers Well Interference Example of One Well Pumping Alone 28

29 Water Audit Considers Well Interference Example of Several Wells Pumping Together 29

30 Model-Generated Water Levels Selected Pauba Wells Vail Lake Release of 4,000 AF Vail Lake Release of 1,000 AF 30

31 Model-Generated Water Levels Selected Temecula Wells Vail Lake Release of 4,000 AF Vail Lake Release of 1,000 AF 31

32 Recommended Production Note: Upper VDC purchased untreated water recharge of 12,700 af and an additional 1,000 to 4,000 af of local water from Vail Lake releases 40,140 Acre-ft 42 Active Wells 32

33 Effective Basin Management Ground Water Management Tools Understanding The Geohydrology RCWD Ground Water Mgmt Plan Yearly Water Audits 33

34 Historical Production Rancho California Water District Production and Artificial Recharge Year FY = Jul-Jun Recommended Groundwater Actual Groundwater Artificial Recharge [AF] Groundwater Production WY = Oct-Sep Production* [AF] Production (AF) Vail Releases Imported Recharge (VDC) Total Less Artificial Recharge [AF] 1990 FY = Jul 89-Jun 90 33,865 33, , FY 34,925-43,725 27,053 6, ,954 20, FY 33,745 29,925 2, ,244 27, FY 30,435-39,035 31,003 31, , FY 32,860 32,421 8, ,469 23, FY 30,750 31,549 11, ,158 20, FY 38,950 34,234 9, ,427 24, FY 35,230 33,224 1,725 1,315 3,040 30, FY 36,750 31,810 4,514 2,785 7,299 24, WY = Oct 98-Sep 99 37,050 37,523 1,010 9,425 10,435 27, WY 40,520 39, ,929 19,929 19, WY 40,555 42, ,080 18,080 24, WY 40,210 39, ,265 16,265 23, WY 40,590 38, ,694 15,694 22, WY 36,845 36, ,088 16,088 20, WY 38,545 38, ,504 16,504 22, WY 38,180 40,216 1,399 18,820 20,219 19, WY 38,090 39, ,175 14,879 24, ? 37,653 4,845 12,419 17,264 20, FY 39,775 40,541 1,236 14,828 16,064 24, FY 37,700 36, ,858 13,659 23, FY 37,500 36,512 2,470 13,873 16,343 20, FY 39,075 39, ,643 14,643 24, FY 38,825 38, FY 39, FY 40, Average ( ) 37,349 35,996 3,824 9,496 13,320 22, * Recommended groundwater production for fiscal year (July through June) for and , and for water year (October through September) for

35 Questions? 35