Water Quality

The 1972 amendments to the Federal Water Pollution Control Act (Clean Water Act) establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters. The Clean Water Act (CWA) made it unlawful to discharge any pollutant from a point source into navigable waters, unless a National Pollutant Discharge Elimination System (NPDES) permit was obtained.

In 1987, the passage of the Water Quality Act established waste discharge requirements that implement the NPDES requirements. The NPDES permit program controls water pollution by regulating point sources that discharge pollutants in stormwater into waters of the United States. Since 1990, the owners and operators of municipal separate storm sewer systems such as the City's stormwater drainage system, has been required to:

  • Develop a stormwater management program designed to prevent harmful pollutants from being dumped or washed by stormwater runoff, into the stormwater system, then discharged into local water bodies, and
  • Obtain an NPDES permit that authorizes the discharges of stormwater.

In California, the NPDES permit programs are administered by the State Water Resources Control Board and by the nine regional boards that issue NPDES permits and enforce regulations within their respective region. The City of San Juan Capistrano is within the jurisdiction of the San Diego Regional Water Quality Control Board.

Orange County lies within the jurisdiction of both the Santa Ana and San Diego Regions. These two regional boards issued our first municipal NPDES permit in 1990 to the "Orange County Stormwater Program," a partnership between the County, all cities within Orange County, and the Orange County Flood Control District. Since the program's inception, the County has served as the Principal Permittee.

NPDES permits are issued for a five-year term and have generally followed a progressive pattern. Our first permit provided an opportunity for Orange County municipalities to establish a program customized to local conditions. In its earliest form, the Orange County Stormwater Program focused on gathering data about existing conditions and implementing an initial set of improvement measures aimed at known water quality deficiencies. Our second permit, issued in 1996, was built upon the knowledge gained during the first permit period and was intended to improve water quality incrementally over time. During the second permit term, Orange County also invested heavily in parallel efforts to implement a watershed approach, a comprehensive but lengthy planning tool for addressing water quality as well as habitat restoration, recreation, and flood control.

Our latest permit was issued in 2013 (Order Number R9-2013-0001) as a regional permit that began with San Diego County, and then amended twice in 2015 to include Orange County (R9-2015-0001) and Riverside County (R9-2015-0100). In this latest permit, the City was required to develop a Jurisdictional Runoff Management Plan (formerly referred to as the Local Implementation Plan) that describes how all requirements of the permit will be managed by the City.

All new and significant redevelopment projects that meet the criteria for preparation of a water quality management plan, per the City's checklist (Guidance for Determining When a WQMP is Required), must follow the 2017 BMP Design Manual.

Water Quality Document Library