In 1972 Congress passed the Clean Water Act to reduce pollution from factories, municipal sewage treatment plants, and similar facilities that pipe wastes to streams, rivers, lakes, or bays.

The 1987 Amendments to the Clean Water Act expanded the pollution reduction mandate to include discharges from Municipal Separate Storm Sewer Systems (MS4s, or storm drains). Around the same time, California began referencing stormwater runoff as a source of pollutants to be controlled under the state’s Porter-Cologne Water Quality Act. The California Water Quality Control Board for the San Francisco Bay Region (RWQCB) issued the first California municipal stormwater National Pollutant Discharge Elimination System (NPDES) permits in 1989. 

The stormwater NPDES permits require owners of MS4s–including cities, towns, and counties, state and regional transportation agencies, flood control districts, and others–to control the myriad sources of pollutants that enter and are transported through their systems. These sources include fertilizers from lawns, sediment from construction sites, dust that settles from the atmosphere, trash left in street gutters, and washwater from cleaning vehicles and equipment. 

Anticipating a stormwater NPDES permit–and with the encouragement of the RWQCB–Contra Costa municipalities established the Contra Costa Clean Water Program (CCCWP) in 1991.Two years later, the RWQCB issued the first permit jointly to the Contra Costa municipalities within the San Francisco Bay Region—these are the cities of Clayton, Concord, El Cerrito, Hercules, Lafayette, Martinez, Orinda, Pinole, Pittsburg, Pleasant Hill, San Pablo, San Ramon and Walnut Creek, the towns of Danville and Moraga, and the western portion of Contra Costa County. In 1994, the Central Valley Regional Water Quality Control Board issued a similar permit to the cities of Brentwood and Antioch. 

To fund the work required under this new mandate, Contra Costa municipalities requested the state Legislature amend the Contra Costa County Flood Control and Water Conservation District Act to authorize collection of a Stormwater Utility Assessment (SUA) on property tax bills. The legislation was adopted in 1993. All Contra Costa jurisdictions except the cities of Richmond and Brentwood participate. All participating municipalities have, over the years, increased the amount assessed to the maximum allowed by the legislation. The SUA revenues are an important, but insufficient, source of funds to enable the municipalities to meet the permit requirements.

Also in 1993-1994, Contra Costa municipalities adopted municipal ordinances that spell out their authorities to implement key aspects of the mandated stormwater pollution prevention program. These authorities include enforcing prohibitions on illegal dumping to storm drains and requiring private property owners to implement Best Management Practices (BMPs) to reduce pollutants in runoff.

The two RWQCBs reissued the municipal stormwater NPDES permits in 1999 and 2000, with additional requirements. The Central Valley permit added the City of Oakley (incorporated in 1999). 

In 2003, the San Francisco Bay RWQCB amended its permit to add Provision C.3, which requires municipal Permittees condition approvals and permits for land development projects to include features and facilities that reduce runoff pollution over the life of the development project. During 2003-2005, CCCWP created and refined a Low Impact Development (LID) approach to implementing the new development requirements. LID uses landscape-based features to detain, retain, and infiltrate stormwater on the development site. Step-by-step instructions were included in a Stormwater C.3 Guidebook, which is now in its 7th Edition. In 2005, the municipal permittees updated their ordinances, based on a CCCWP model, to spell out the new development requirements and to reference the criteria in the Guidebook.

In 2009, the San Francisco Bay RWQCB consolidated permits issued to municipal permittees in Contra Costa, Alameda, Santa Clara, San Mateo, and Solano counties into a single Municipal Regional Stormwater Permit (MRP) with 75+ local government agencies as permittees. In 2010, the Central Valley Regional Water Quality Control Board issued a permit with similar conditions to the cities of Antioch, Oakley, and Brentwood, and Contra Costa County. In addition to continuing the previous requirements, the MRP required municipalities to plan and implement strategies to eliminate trash from entering the storm drain systems and to radically reduce the amount of PCBs and mercury entering storm drains in accordance with Total Maximum Daily Loads (TMDLs) adopted by the RWQCB in 2006 (for mercury) and 2008 (for PCBs). A TMDL is a calculation of the maximum amount of pollutants that may be discharged to a water body without causing its uses to be impaired.

The 2009 MRP also updated the new development requirements to require that new land development projects use solely LID techniques and technologies to treat stormwater runoff. Those requirements went into effect in 2011. Some refinement of the requirements, and some exceptions, were incorporated in a 2011 permit amendment. Many of the new regional LID requirements were largely the same as those developed in Contra Costa over the previous 8 years.

In 2012, aware that the always-expanding permit requirements would soon outstrip municipalities’ ability to fund compliance, the municipalities approved a Stormwater Funding Initiative to be put forward to Contra Costa property owners in accordance with the requirements of Proposition 218 (1996). The proposed parcel tax failed. In the years since, municipalities have seen a significant shortfall of funds to implement the state and Federal stormwater pollution prevention mandate.

The San Francisco Bay RWQCB reissued the MRP (MRP 2.0) in 2015.The second iteration of the permit expanded mandates to implement PCB-reduction activities, including requirements to condition permits to demolish certain types of buildings with requirements to manage PCBs in demolition wastes. Permittees must also identify and remediate, or refer for remediation, industrial sites which may be sources of PCB-laden sediment entering nearby storm drains. MRP 2.0 also requires each Permittee to prepare a Green Infrastructure Plan intended to describe how the Permittee will, over the long term, shift impervious surfaces and storm drain infrastructure from “gray,” conventional concrete infrastructure to a more resilient, sustainable green infrastructure system that slows runoff by dispersing it to vegetated areas, harvests and uses runoff, promotes infiltration, and uses bioretention to clean runoff. Permittees must also prepare an implementation plan and Reasonable Assurance Analysis (RAA) showing how specified pollutant reductions (wasteload allocations) will be met by 2030 (for PCBs) and 2040 (for mercury). The Permittees’ Green Infrastructure Plans were submitted in September 2019 (2020 for Antioch, Brentwood, and Oakley) and the countywide RAA and PCBs and mercury implementation plan were submitted in September 2020.

In 2016 CCCWP sought and received a grant from the State Water Resources Control Board (SWRCB) to prepare a Contra Costa Watersheds Storm Water Resource Plan (CCW SWRP) to advance stormwater management projects and programs within the county. The CCW SWRP identifies potential projects that are eligible to apply for grant funds administered by the SWRCB. The CCW SWRP was submitted in 2019 and accepted by the SWRCB in 2020.

In 2019, the San Francisco Bay RWQCB, with the assent of the Central Valley RWQCB, amended MRP 2.0 to add the cities of Antioch, Brentwood, and Oakley as Permittees, bringing municipal stormwater NPDES compliance activities throughout Contra Costa County under the same regional permit. 

In 2020 CCCWP staff and municipal Permittee staff negotiated requirements to be included in the next iteration of the MRP.

MRP 3.0 was reissued in May 2022, with new requirements phased in beginning July 1, 2022.