2015 NCMA Annual Report
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FUGRO CONSULTANTS, INC. NORTHERN CITIES MANAGEMENT AREA 2015 ANNUAL MONITORING REPORT Prepared for: The Northern Cities Management Area Technical Group City of Arroyo Grande City of Grover Beach Oceano Community Services District City of Pismo Beach Prepared by: Fugro Consultants, Inc. April 27, 2016 FUGRO CONSULTANTS, INC. 5855 Capistrano Ave, Suite C Atascadero, California 93422 T (805) 468-6060 April 27, 2016 Project No. 04.62150079 Northern Cities Management Area Northern Cities Management Area 2015 Annual Monitoring Report Fugro Consultants, in collaboration with Rob Almy, PG, and GEI Consultants, Inc., is pleased to submit the 2015 Annual Monitoring Report for the Northern Cities Management Area. The report is prepared pursuant to the requirements of the Stipulation and Judgment After Trial for the Santa Maria Groundwater Adjudication. The report is prepared on behalf of the Northern Cities Management Area, which is comprised of the City of Arroyo Grande, City of Grover Beach, Oceano Community Services District, and City of Pismo Beach. Sincerely, FUGRO CONSULTANTS, INC. Paul A. Sorensen, PG, CHg Keith P. Askew, PE Principal Hydrogeologist Principal Engineer (currently with GSI Water Solutions, Inc.) Project Manager GEI CONSULTANTS, INC. Robert Almy, PG Samuel W. Schaefer, PE Senior Engineer A member of the Fugro group of companies. NCMA 2015 Annual Monitoring Report April 27, 2016 (Project No. 04.62150079) CONTENTS Page 1.0 EXECUTIVE SUMMARY .................................................................................................. 1 1.1 Groundwater Conditions ........................................................................................ 1 1.1.1 Groundwater Levels ...................................................................................... 1 1.1.2 Groundwater Quality ..................................................................................... 2 1.2 Water Supply and Demand ................................................................................... 2 1.3 Threats to Water Supply ........................................................................................ 3 2.0 INTRODUCTION ............................................................................................................... 4 2.1 Description of the Northern Cities Management Area Technical Group ................ 5 2.2 Coordination with Management Areas .................................................................. 6 3.0 BASIN DESCRIPTION ...................................................................................................... 7 3.1 Setting ................................................................................................................... 7 3.2 Precipitation ........................................................................................................... 7 3.3 Evapotranspiration ................................................................................................ 8 4.0 GROUNDWATER CONDITIONS ...................................................................................... 9 4.1 Groundwater Monitoring Network .......................................................................... 9 4.2 Groundwater Levels ............................................................................................ 10 4.2.1 Groundwater Level Contour Maps. ............................................................. 10 4.2.2 Basin-Wide Historical Hydrographs. ........................................................... 10 4.2.3 Sentry Wells. ............................................................................................... 11 4.3 Water Quality ....................................................................................................... 12 4.3.1 Quarterly Groundwater Monitoring ............................................................. 12 4.3.2 Analytical Results Summary ....................................................................... 12 5.0 WATER SUPPLY AND DEMAND ................................................................................... 14 5.1 Water Supply ....................................................................................................... 14 5.1.1 Lopez Lake ................................................................................................. 14 5.1.2 State Water Project ..................................................................................... 16 5.1.3 Groundwater ............................................................................................... 17 5.1.4 Developed Water ........................................................................................ 19 5.1.5 Total Water Supply Availability ................................................................... 19 5.2 Water Demand .................................................................................................... 21 5.2.1 Applied Irrigation Demand .......................................................................... 21 5.2.2 Rural Demand ............................................................................................. 22 5.2.3 Urban Demand ........................................................................................... 23 5.2.4 2015 Groundwater Pumpage ...................................................................... 24 5.2.5 Changes in Water Demand ........................................................................ 25 6.0 COMPARISON OF WATER SUPPLY V. WATER DEMAND.......................................... 27 NCMA 2015 Annual Report - i - NCMA 2015 Annual Monitoring Report April 27, 2016 (Project No. 04.62150079) 7.0 THREATS TO WATER SUPPLY .................................................................................... 29 7.1 Threats to Local Groundwater Supply ................................................................. 29 7.1.1 Declining Water Levels ............................................................................... 29 7.1.2 Seawater Intrusion ...................................................................................... 30 7.1.3 Measures to Avoid Seawater Intrusion ....................................................... 30 7.2 Threats to State Water Project Supply ................................................................ 31 7.3 Threats to Lopez Lake Water Supply .................................................................. 31 8.0 MANAGEMENT ACTIVITIES .......................................................................................... 32 8.1 Management Objectives ...................................................................................... 32 8.1.1 Share Groundwater Resources and Manage Pumping .............................. 35 8.1.2 Enhance Management of NCMA Groundwater .......................................... 36 8.1.3 Monitor Supply and Demand and Share Information .................................. 37 8.1.4 Manage Groundwater Levels and Prevent Seawater Intrusion .................. 38 8.1.5 Protect Groundwater Quality ...................................................................... 40 8.1.6 Manage Cooperatively ................................................................................ 41 8.1.7 Encourage Water Conservation .................................................................. 42 8.1.8 Evaluate Alternative Sources of Supply ...................................................... 47 9.0 REFERENCES ................................................................................................................ 50 TABLES Page Table 1. NCMA TG Representatives ........................................................................................... 5 Table 2. Lopez Lake (SLOCFC&WCD Zone 3 Contractors) 2015 Water Allocation under LRRP 10% Diversion Reduction Strategy (AFY) ................................................................ 14 Table 3. Lopez Lake Municipal Diversion Reduction Strategy Low Reservoir Response Plan . 15 Table 4. Lopez Lake Downstream Release Reduction Strategy Low Reservoir Response Plan .......................................................................................................................... 15 Table 5. 2015 Lopez Lake Deliveries (AF) ................................................................................. 16 Table 6. NCMA Groundwater Pumpage from Santa Maria Groundwater Basin, 2015 (AF) ...... 19 Table 7. Baseline (Full Allotment) Available Urban Water Supplies (AFY) ................................ 20 Table 8. 2015 Available Urban Water Supply, under 2015 Lopez LRRP 10% Municipal Reduction Diversion (AF) ......................................................................................... 20 Table 9. 2015 NCMA Crop Acreages and Evapotranspiration .................................................. 22 Table 10. Estimated Rural Water Demand ................................................................................ 23 Table 11. Urban Water Demand (Groundwater and Surface Water, AF) .................................. 24 Table 12. NCMA Groundwater Pumpage from Santa Maria Groundwater Basin, 2015 (AF) .... 24 Table 13. Total Water Demand (Groundwater and Surface Water, AF) .................................... 25 Table 14. 2015 Water Demand by Source (AF) ......................................................................... 27 NCMA 2015 Annual Report - ii - NCMA 2015 Annual Monitoring Report April 27, 2016 (Project No. 04.62150079) FIGURES (following text) Figure 1. Santa Maria Groundwater Basin Figure 2. Northern