RANCHO CALIFORNIA WATER DISTRICT GROUNDWATER WORKSHOP by: Dennis Williams July 22, 2014 1
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-15 22-Jul-14 2
Upper Santa Margarita River Basin Lower Santa Margarita River Basin 3 3
Upper Santa Margarita River Watershed 4 22-Jul-14 4
Geologic Map 5 5
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
Aquifer Systems Stream Younger Alluvium 500 ft Pauba Aquifer Temecula Aquifer 1,000 ft 22-Jul-14 7
Basin Divided Into Eleven Hydrologic Subunits 22-Jul-14 8
Pauba Valley Hydrologic Subunit 22-Jul-14 9
Ground Water Management Process Planning, Implementation And Operation Necessary To Provide Safe And Reliable Ground Water Supplies 22-Jul-14 10
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
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
Sustainable Yield Example PUMPING = 200 RECHARGE = 100 STORAGE CHANGE = - 100 Long Term Pumping Greater Than Recharge Exceeds Sustainable Yield 22-Jul-14 13
Sustainable Yield Example PUMPING = 200 Artificial Recharge = 100 Natural Recharge = 100 STORAGE CHANGE = 0 Artificial Recharge Increases Sustainable Yield 22-Jul-14 14
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
CWRMA Model Update and Refinement 3D Lithologic Model Used Watershed Model (PRMS) Incorporated 16
400 ft Model Grid and Active/Inactive Cells 1 1 PRMS 320 MODFLOW-2005 400 ft Inactive Active 300 22-Jul-14 17
Lithologic Model 5 Layers 18
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
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
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 1994-2008 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. 100 10 1 Results of the model calibration indicate a good match of daily measured and model-calculated streamflow in creeks within the model area. 0 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Date Temecula Gorge Figure 68 22-Jul-14 21
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
RCWD Index Well Group 1 21 2 3 20 18 16 15 4 19 17 14 5 9 10 11 12 13 21 Index Wells Characterize the Entire Basin 6 8 7 7 8 23
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
Annual Water Audits RCWD Conducts Yearly Water Audits (1-Jul-14 30-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
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 1,400 450 400 Land Surface 1,300 350 1,200 300 1,100 250 200 Production Recommended production for 2014-2015: 900 acre-ft 1,000 150 900 100 50 800 0 700 1981 1985 1989 1993 1997 2001 2005 2009 2013 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 WELL 109 500 1,200 450 400 Land Surface 1,100 350 1,000 300 900 250 200 800 150 100 50 Production Recommended production for 2014-2015: 700 acre-ft 700 600 0 500 1981 1985 1989 1993 1997 2001 2005 2009 2013 27
Water Audit Considers Well Interference Example of One Well Pumping Alone 28
Water Audit Considers Well Interference Example of Several Wells Pumping Together 29
Model-Generated Water Levels Selected Pauba Wells Vail Lake Release of 4,000 AF Vail Lake Release of 1,000 AF 30
Model-Generated Water Levels Selected Temecula Wells Vail Lake Release of 4,000 AF Vail Lake Release of 1,000 AF 31
2014-2015 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
Effective Basin Management Ground Water Management Tools Understanding The Geohydrology RCWD Ground Water Mgmt Plan Yearly Water Audits 33
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 33,243 0 0 0 33,243 1991 FY 34,925-43,725 27,053 6,253 701 6,954 20,099 1992 FY 33,745 29,925 2,244 0 2,244 27,681 1993 FY 30,435-39,035 31,003 31,704 0 31,704-701 1994 FY 32,860 32,421 8,469 0 8,469 23,952 1995 FY 30,750 31,549 11,158 0 11,158 20,391 1996 FY 38,950 34,234 9,427 0 9,427 24,807 1997 FY 35,230 33,224 1,725 1,315 3,040 30,184 1998 FY 36,750 31,810 4,514 2,785 7,299 24,511 1999 WY = Oct 98-Sep 99 37,050 37,523 1,010 9,425 10,435 27,088 2000 WY 40,520 39,915 0 19,929 19,929 19,986 2001 WY 40,555 42,153 0 18,080 18,080 24,073 2002 WY 40,210 39,875 0 16,265 16,265 23,610 2003 WY 40,590 38,183 0 15,694 15,694 22,489 2004 WY 36,845 36,395 0 16,088 16,088 20,307 2005 WY 38,545 38,948 0 16,504 16,504 22,444 2006 WY 38,180 40,216 1,399 18,820 20,219 19,997 2007 WY 38,090 39,727 704 14,175 14,879 24,848 2008? 37,653 4,845 12,419 17,264 20,389 2009 FY 39,775 40,541 1,236 14,828 16,064 24,477 2010 FY 37,700 36,743 801 12,858 13,659 23,084 2011 FY 37,500 36,512 2,470 13,873 16,343 20,169 2012 FY 39,075 39,060 0 14,643 14,643 24,417 2013 FY 38,825 38,711 - - - - 2014 FY 39,080 - - - - - 2015 FY 40,140 - - - - - Average (1990-2012) 37,349 35,996 3,824 9,496 13,320 22,676 34 * Recommended groundwater production for fiscal year (July through June) for 1990-1998 and 2009-2015, and for water year (October through September) for 1999-2007
Questions? 35