California Department of Water Resources: Management and Policy

The California Department of Water Resources (DWR) administers the state's most complex and consequential natural resource system — a statewide water infrastructure network serving approximately 27 million Californians and irrigating roughly 750,000 acres of farmland. This page covers DWR's statutory mandate, operational structure, regulatory decision processes, and the boundaries of its authority relative to federal agencies and local water districts.

Definition and Scope

DWR operates under the authority of the California Water Code, functioning as the primary state agency responsible for managing, planning, and developing California's water resources. Established in 1956 under Governor Goodwin Knight, the department is organized within the California Natural Resources Agency and coordinates directly with the California Department of Finance on capital budgeting for major infrastructure.

DWR's statutory scope encompasses:

  1. State Water Project (SWP) operations — The SWP is the largest state-built water and power development system in the United States, comprising 34 storage facilities, 700 miles of canals and pipelines, and 20 pumping plants (DWR, State Water Project Overview).
  2. Flood management — Oversight of levee systems protecting Sacramento–San Joaquin Delta communities and coordination with the Central Valley Flood Protection Board.
  3. Dam safety — DWR's Division of Safety of Dams regulates approximately 1,250 non-federal jurisdictional dams in California under Water Code §6000 et seq.
  4. Water supply planning — Integrated Regional Water Management (IRWM) grant programs and long-range supply forecasting.
  5. Groundwater sustainability — Implementation of the Sustainable Groundwater Management Act (SGMA, 2014), which designated 127 critically overdrafted or high-priority basins requiring locally developed sustainability plans (DWR, SGMA Portal).

DWR does not regulate water rights — that authority rests with the State Water Resources Control Board (SWRCB). Water quality standards are likewise outside DWR's primary mandate and fall under SWRCB and the California Air Resources Board for atmospheric deposition issues.

Scope limitations: DWR's authority applies to state-operated infrastructure and state-funded programs. Federally operated Central Valley Project (CVP) facilities — managed by the U.S. Bureau of Reclamation — fall outside DWR's operational jurisdiction, though DWR and the Bureau coordinate water delivery under coordinated operating criteria. Tribal water rights adjudications and interstate compact obligations (e.g., the Colorado River Compact) involve federal oversight that supersedes state department authority.

How It Works

DWR's operational structure divides into four primary functional areas: water operations, flood management, dam safety, and planning and local assistance.

Water operations center on the State Water Project, which delivers water to 29 public water agencies — including the Metropolitan Water District of Southern California and the Kern County Water Agency — through long-term water supply contracts (DWR, SWP Contractors). Delivery allocations are set annually based on snowpack measurements, reservoir storage levels, and regulatory constraints including environmental flow requirements under the Endangered Species Act.

Flood management involves DWR's coordination role within the Central Valley Flood Protection Plan, updated every five years under Water Code §9612. DWR does not directly maintain all levees — local reclamation districts own and operate the majority — but the department sets design standards and administers State–Federal levee subvention programs.

Dam safety operates through mandatory inspection cycles. Non-federal dams taller than 25 feet or with a storage capacity exceeding 50 acre-feet require DWR Division of Safety of Dams permits and periodic engineering inspections. Failure to comply constitutes a misdemeanor under Water Code §6450.

Groundwater management under SGMA assigns DWR a supervisory role: local Groundwater Sustainability Agencies (GSAs) develop and implement plans, but DWR evaluates those plans for adequacy. Plans deemed inadequate trigger DWR intervention and potential state management of the basin.

Common Scenarios

Annual SWP allocation announcements occur between December and May each year. DWR issues preliminary allocation percentages in December reflecting early-season hydrology, then adjusts through spring runoff data. In drought years, SWP contractors have received allocations as low as 0% of their Table A contract amounts, as occurred in 2022 (DWR, SWP Delivery Reliability Report).

SGMA compliance reviews follow a structured timeline. DWR reviews groundwater sustainability plans submitted by GSAs and issues completeness and adequacy determinations. Basins found inadequate face probationary status and potential State Water Board intervention — a consequence with significant implications for agricultural water users in the San Joaquin Valley, including Fresno County and Kern County.

Flood emergency coordination activates when atmospheric river events threaten Sacramento Valley infrastructure. DWR operates the Flood Operations Center, issuing bulletins and coordinating releases from Shasta, Oroville, and Folsom reservoirs in conjunction with the U.S. Army Corps of Engineers.

Dam safety incidents trigger DWR's emergency response authority. The 2017 Oroville Dam spillway failure — which prompted the evacuation of approximately 188,000 downstream residents — led to DWR-directed repairs exceeding $1.1 billion (California Department of Finance, Oroville Dam Emergency Expenditures, 2019).

Decision Boundaries

DWR decision authority is bounded by three intersecting frameworks:

Federal supremacy — Federal reclamation law and Endangered Species Act biological opinions constrain SWP operations regardless of state priorities. DWR cannot exceed pumping limits set by federal biological opinions protecting delta smelt and salmon runs.

Water rights hierarchy — DWR holds water rights for SWP operations, but those rights are administered by SWRCB. Curtailment orders from SWRCB override DWR operational preferences during droughts.

Local agency autonomy — Under SGMA, GSAs retain primary responsibility for groundwater basin management. DWR's intervention authority is remedial, not proactive; it activates only after a plan is determined inadequate or a basin enters probationary status.

The distinction between DWR and SWRCB is operationally significant: DWR builds and manages infrastructure and plans supply; SWRCB allocates legal rights to use that water and enforces quality standards. Professionals navigating California's water regulatory landscape — including municipal water agencies, agricultural water districts, and environmental consultants — reference the broader structure of California government to understand how DWR decisions interact with legislative appropriations processed through the California State Legislature.

References