Water Supply Master Plan

"DRAFT" - SLVWD Water Supply Master Plan May 2009

Table of Contents

Report Cover
Table of Contents
1 Introduction..................................................................................................1-1
Figures
2 Past and Projected Water Demand................................................................2-1
Figures
Tables
2.1 Available Information .................................................................................2-1
2.2 Analysis of Historical Record .....................................................................2-1
2.3 SLVWD Projections for 2005-2030..........................................................2-3
3 Climate and Hydrology .................................................................................3-1
Figures
Tables
3.1 Rainfall .......................................................................................................3-1
3.1.1 Areal Distribution .....................................................................................3-1
3.1.2 Seasonal Variation and Extremes ..............................................................3-2
3.1.3 Historical Variation....................................................................................3-2
3.2 Evapotranspiration........................................................................................3-3
3.3 Streamflow ..................................................................................................3-5
3.3.1 Gaged Watersheds ....................................................................................3-5
3.3.2 Seasonal Variation and Extremes ...............................................................3-6
3.3.3 Historical Variation.....................................................................................3-6
3.3.4 Stream Baseflow........................................................................................3-7
3.4 Past and Potential Climatic Change ...............................................................3-7
3.4.1 State and Global Climatic Record ..............................................................3-7
3.4.2 Local Climatic Record ...............................................................................3-8
3.4.3 Climate Predictions.....................................................................................3-8
3.5 Design Climatic Cycle....................................................................................3-9
4 Stream Diversions.............................................................................................4-1
Figures
Tables
4.1 Diversion Watersheds.....................................................................................4-1
4.1.1 Physiography ..............................................................................................4-1
4.1.2 Land Use....................................................................................................4-3
4.1.3 Hydrology ..................................................................................................4-4
4.1.4 Water Quality..............................................................................................4-8
4.2.1 Intakes.........................................................................................................4-8
4.2.2 Raw-Water Conveyance and Mixing.............................................................4-9
4.2.3 Treatment Plant.............................................................................................4-9
4.3 Surface-Water Production ...............................................................................4-11
4.3.1 Diversion Record ..........................................................................................4-11
4.3.2 Operational Procedures and Constraints.........................................................4-14
4.3.3 Production Potential.......................................................................................4-15
5 Groundwater Sources..........................................................................................5-1
Figures
Tables
5.1 Groundwater Subareas .....................................................................................5-1
5.1.1 Quail Hollow..................................................................................................5-2
5.1.2 Olympia ........................................................................................................5-3
5.1.3 Pasatiempo....................................................................................................5-3
5.1.4 Camp Evers...................................................................................................5-4
5.1.5 Mission Springs .............................................................................................5-5
5.1.6 Scotts Valley..................................................................................................5-5
5.2 Hydrogeology...................................................................................................5-5
5.2.1 Hydrogeologic Units.......................................................................................5-5
5.2.2 Hydrogeologic Structure.................................................................................5-8
5.2.3 Hydrogeologic Boundaries .............................................................................5-10
5.2.4 Aquifer Properties...........................................................................................5-11
5.2.5 Groundwater Occurrence, Movement, and Storage..........................................5-13
5.3 Infrastructure and Operations..............................................................................5-19
5.3.1 Production Wells.............................................................................................5-19
5.3.2 Operations, Treatment, Conveyance, and Surface Storage................................5-22
5.4 Historical Groundwater Production and Water Levels .........................................5-23
5.4.1 Quail Hollow....................................................................................................5-25
5.4.2 Olympia ..........................................................................................................5-26
5.4.3 Pasatiempo.......................................................................................................5-27
5.4.4 Camp Evers......................................................................................................5-28
5.4.5 Scotts Valley.....................................................................................................5-29
5.5 Groundwater Quality.......................................................................................... ..5-29
5.5.1 Quail Hollow......................................................................................................5-29
5.5.2 Olympia ............................................................................................................5-30
5.5.3 Pasatiempo........................................................................................................5-31
5.5.4 Camp Evers and Scotts Valley............................................................................5-32
5.6 Groundwater Budget .............................................................................................5-32
5.6.1 Quail Hollow.......................................................................................................5-33
5.6.2 Olympia .............................................................................................................5-34
5.6.3 Mission Springs ..................................................................................................5-36
5.6.4 Pasatiempo..........................................................................................................5-37
5.6.5 Camp Evers........................................................................................................5-38
5.6.6 Scotts Valley.......................................................................................................5-39
5.7 Groundwater Management and Protection...............................................................5-39
5.7.1 Institutional ..........................................................................................................5-39
5.7.2 Recharge-Area Protection....................................................................................5-40
5.8 Production Potential ...............................................................................................5-42
5.8.1 Quail Hollow........................................................................................................5-42
5.8.2 Olympia ...............................................................................................................5-43
5.8.3 Pasatiempo...........................................................................................................5-45
5.8.4 Camp Evers..........................................................................................................5-46
6 Potential Other Sources ..............................................................................................6-1
Figures
Tables
6.1 Loch Lomond Reservoir...........................................................................................6-1
6.1.1 Watershed ...........................................................................................................6-2
6.1.2 Infrastructure and Operation..................................................................................6-2
6.1.3 Historic Yield........................................................................................................6-3
Nicholas M. Johnson, PhD, RG, CHg
Water Resources Consultant
iii
SLVWD Water Supply Master Plan May 2009
6.1.4 SLVWD Expected Potential Yield ........................................................................6-4
6.2 SCCWD Treated Water..........................................................................................6-4
7 System Production .....................................................................................................7-1
Figures
Tables
7.1 Existing and Planned System Infrastructure and Operation.........................................7-1
7.1.1 Storage ................................................................................................................7-1
7.1.2 Distribution ..........................................................................................................7-1
7.1.3 Operations...........................................................................................................7-2
7.1.4 North-South System Intertie ................................................................................7-2
7.1.5 Loch Lomond Diversion.......................................................................................7-3
7.1.6 Expanded Groundwater Production Capacity and Treatment ................................7-3
7.2 Past and Current Conjunctive Use............................................................................7-3
7.3 Potential Future Conjunctive Use..............................................................................7-5
7.3.1 Assumptions ........................................................................................................7-6
7.3.2 Alternate 2030 Conjunctive-Use Scenarios...........................................................7-8
7.3.3 Conclusions..........................................................................................................7-13
8 Recommendations.......................................................................................................8-1
9 References and Bibliography........................................................................................9-1