The State Water Board’s Division of Drinking Water’s twenty-four Field Operation Branch districts are responsible for the regulation of public water systems to provide safe water to all Californians that they serve. The field offices conduct inspections, issue permits, determine compliance with the Safe Drinking Water Act, and conduct enforcement activities. The Division’s Program Management Branch develops regulations, approves innovative treatment technologies, accredits environmental laboratories, maintains water quality databases and websites, integrates recycled water with potable water uses, and maintains quality assurance systems.

The State Water Board's Division of Financial Assistance provides loans and grants for constructing drinking water treatment and distribution systems, municipal sewage and water recycling facilities, remediation for groundwater contamination and underground storage tank releases, stormwater capture and use, and for nonpoint source pollution control projects. The State Water Board has several financial programs to help local agencies, public water systems, California Native American Tribes, non-profit organizations, and individuals prevent or clean up pollution of the state’s water and provide safe drinking water.

The State Water Board's Division of Water Quality works in coordination with the nine Regional Water Boards to preserve, protect, enhance, and restore water quality. The State Water Board sets statewide water quality standards, issues statewide general permits, conducts statewide surface and groundwater monitoring and assessment, and issues orders for cleaning up contaminated sites. The State and Regional Water Boards also work with federal, state, and local agencies, as well as other environmental agencies to ensure a coordinated approach to protecting human health and the environment.

The State Water Board's Office of Research, Planning, and Performance consists of a team of dedicated staff from varying professional backgrounds. We provide focus and support for priorities, initiatives, issues, and challenges facing the State and Regional Water Boards. The Office works on a variety of important issues that impact every Californian, including addressing climate change impacts to our water resources, making water conservation a way of life, focusing on water affordability for low-income families, managing our groundwater resources sustainably, coordinating professional peer reviews for our projects, performing in-depth economic analyses with our programs, and developing and implementing innovative training for our staff.

Anyone wanting to divert water from a stream or river not adjacent to their property, or anyone wanting to store water, must first apply for a water right permit from the State Water Board's Division of Water Rights. The Division of Water Rights issues permits for water rights specifying amounts, conditions, and construction timetables for diversion and storage. Decision-making stems from water availability, senior water rights, flows needed to preserve instream uses, such as recreation and fish habitat, and whether the diversion is in the public interest.

The State Water Board’s Bay-Delta Program facilitates the development and review of plans and policies to protect beneficial uses of the San Francisco Bay / Sacramento – San Joaquin Delta Estuary.

The State Water Board's Office of Information Management and Analysis was established in 2008 to serve as an advocate for data management, a bridge between data collectors and users, as well as, provide transparency of the Water Board’s information management infrastructure. Our goal at OIMA is to collaborate monitoring efforts, accurately analyze data, make our data easily accessible, and create visualizations and reports that make data understandable across all audiences.

There are nine Regional Water Quality Control Boards statewide. The nine Regional Water Boards are semi-autonomous and are comprised of seven part-time Board members appointed by the Governor and confirmed by the Senate. Regional boundaries are based on watersheds and water quality requirements are based on the unique differences in climate, topography, geology, and hydrology for each watershed. Each Regional Board makes critical water quality decisions for its region, including setting standards, issuing waste discharge requirements, determining compliance with those requirements, and taking appropriate enforcement actions.