Table of Contents

List of Tables

List of Figures

Preface

1. Introduction

2. Water Use and Supplies
County setting
1990 water use estimates
Future water use projections
Average water supplies
Summary

3. Groundwater Resources, Pumping, and Sustained Yield
Spatial distribution of groundwater pumping
Impact of drought on groundwater use
Impact of water transfers on groundwater use
Assessment of sustained yield
Definition of sustained yield and effects of overdraft
Groundwater recharge: sources and magnitudes
Recharge from irrigation and drainage canals
Deep percolation of irrigation water
Deep percolation of rainfall
Subsurface inflows
Assessment of recharge situation
Groundwater discharge: sources and magnitudes
Groundwater balance calculation
Overdraft and overdraft-related problems
Summary

4. Conjuctive Use Management of the Groundwater Basin
Comparison of groundwater and surface water characteristics
Availability and storage
Access and distribution
Quality and treatment
Legal rights
Costs
Reliability and local control
Sources of water for artificial recharge
Unmanaged Cache Creek surface water
Treated urban wastewater
Surface water from outside Yolo County
Artificial recharge opportunities
Recharge using irrigation distribution system canals
Winter season irrigation applications
Cache Creek induced recharge for Davis/Woodland supplies
The YCFCWCD Cache Creek recharge concept
Enhanced recharge along lower Cache Creek
Injection wells
Sacramento River induced recharge
Within County exchanges and redistribution of water supplies
Potential roles of planned water transfers and exchanges
Summary

5. Planning Conjuctive Use Management
Constraints on implementing conjunctive use management
Institutional weakness
Groundwater information gaps
Multi-objective, multi-purpose decision-making
Complexities of cost-sharing and financing
Getting farmers' participation and support
Groundwater rights and legal considerations
Implications for planning
Institutional considerations
Developing technical analysis of groundwater resources
Timing of steps in the planning process
Summary

6. Conclusions and Recommendations
Conclusions
Recommendations
References

Appendix A: Water Use and Supplies, Data and Calculations

Appendix B: Groundwater Data and Analysis

Appendix C: Other Data and Maps

Appendix D: Explanation of Compaction and Subsidence