Overview -- Groundwater Management in California

1. Overview -- Groundwater Management in California Western States Water Council April 2004

2. GW resources background • Supports about 30% of California urban & ag needs in average water years • Important drought resource • Supplies majority of state’s public water systems (largest urban agencies use surface water, almost all small systems use groundwater)

3. Rights to use of groundwater • Not administered by State (unlike surface water) • Developed through case law

4. Case law examples • City of Los Angeles v. City of San Fernando (1975) – mutual prescription not applicable between public agencies • Niles Sand & Gravel Co. v. Alameda County Water District (1974) – public agencies can store water underground & recover stored water

5. Impetus for GW management • Seawater intrusion – widespread by 1950s • Overdraft, land subsidence • Fear of exports • State financial assistance • Other

6. Physical realities of GW management • Limit/regulate extraction • Develop new in-basin surface supply • Bring in new imported water source • Storage/conjunctive use projects require available aquifer capacity, conveyance, and surface water source

9. GW management techniques • Basin adjudication in court (19) • Special or general act districts • AB 3030 plans (>160 agencies) • County ordinances (28)

10. Basin adjudications • Expensive • Entail years in court system

11. AB 3030 plans • Enabling legislation enacted in 1992 • Plan adoption is voluntary • Hydrologic/hydrogeologic/political boundaries often differ • Plans may be multi-agency • Are they effective?

12. GW storage projects increasing • Existing “large” projects w/ ballpark of 10 MAF total managed capacity • More than $500M in state financial assistance authorized 1996-2000 • Many “small” and “medium” projects now in planning stages, reflecting availability of substantial state funding