Agricultural Orders Regulate California Irrigation Discharges

Farmers and ranchers statewide must submit water test results and develop nutrient management plans for their land holdings under California state law.

Why these regulations exist:

In 1969, California passed the Porter-Cologne Water Quality Control Act, which gave the State Water Resources Control Board authority over the state’s water rights and water quality policy.Porter-Cologne also established nine Regional Water Quality Control Boards (RWQCBs) to manage water quality on a regional basis. The regional boards are responsible for preparing and updating Basin Plans for their geographical areas and for regulating all pollutant discharges that may impact surface or groundwater quality.

Fast forward to 2003, California created the Irrigated Lands Regulatory Program to address waste discharged from irrigated lands such as sediments, pesticides, and nitrates. Prior to 2003, waste discharged from irrigated lands were exempt from regulation under a broad waiver.

Since 2003, the RWQCBs have been replacing the broad waiver with regional and commodity-based Waste Discharge Requirements, which are issued under Agricultural Orders. In many regions, the deadline to register under the Agricultural Order was set for fall 2014. Therefore, many growers have recently been notified by their regional water boards that they need to enroll.

Who must comply:

All landowners who manage commercial irrigated property, including greenhouses and nurseries, are subject to the Waste Discharge Requirements or conditional waivers of these requirements. Under state law, they are subject to Agricultural Orders from their RWQCBs.

How to comply:

To comply, landowners have the choice to be regulated as an individual grower or to join a coalition, which provides region-wide monitoring and water quality management plans. In either case, fees to the state or the coalition are collected annually. 12 regional coalitions currently exist and a 13th coalition is in development.

Requirements for compliance vary by region. For example, the Central Coast RWQCB has established a tier-based system that classifies level of regulation by chemical usage, proximity to an impaired water body, and type of crops grown.

Where to find more information:

For more information, find your RWQCB on this map and contact them directly, or contact state Irrigated Lands Program staff via phone at (916) 464-4611 or via e-mail at

1This legislation was very influential and was the basis of the federal Clean Water Act passed in 1972.