Overview -- Groundwater Management in California

Western States Water Council

April 2004

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)

Rights to use of groundwater

Not administered by State (unlike surface water)

Developed through case law

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

Impetus for GW management

Seawater intrusion – widespread by 1950s

Overdraft, land subsidence Fear of exports State financial assistance Other

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

GW management techniques

Basin adjudication in court (19) Special or general act districts AB 3030 plans (>160 agencies) County ordinances (28)

Basin adjudications

Expensive Entail years in court system

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?

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