Regional MS4 Permit for Santa Ana River Watershed Released for Public Review and Comment
The Santa Ana Regional Water Quality Control Board released a DRAFT region-wide Phase I Municipal Separate Stormwater Sewer System Permit (MS4) for public review and comment in March 2024. It is holding public workshops and accepting comments through July 3, 2024. A public workshop is scheduled for Thursday, June 6, 2024, where the Board members will receive an updated presentation from the Board staff and additional input from interested stakeholders, including public works representatives from the three-county area.
The DRAFT MS4 permit is the first of its kind in the Santa Ana region, where each county previously maintained individual, county-wide permits. The permit combines three existing Phase I MS4 permits for north Orange, western Riverside, and western San Bernardino counties into a single regional permit encompassing the Santa Ana River watershed area. The three existing MS4 permits were last renewed and adopted between 2009 and 2012.
The Regional Board proposes several new permit elements that will change how the three counties implement the permit's provisions. These include changes to the New Development and Significant Redevelopment section of the DRAFT permit, which impacts the building and construction industry tasked with designing, installing, operating, and maintaining post-construction stormwater runoff volume and treatment controls.
Of most concern to the building and construction industry are costly new mandatory requirements for watershed plan preparation, loss of hydromodification control exemptions for formerly designated channels and waterways, and more stringent on-site requirements for roadways to manage and treat stormwater runoff on-site as part of new and redevelopment projects. Also noteworthy in the DRAFT MS4 permit is a new, region-wide water quality credit trading program as part of the new and significant redevelopment project approval process, which would be available to all permittees to meet their stormwater runoff volume and treatment requirements when a property is developed or redeveloped.
CICWQ has worked for many years with the Regional Board, its members, staff, and public works agencies in the three-county area to consider changes to their existing MS4 permits. These would protect water quality and increase compliance flexibility for new and redevelopment projects within the Board’s jurisdiction. The links below provide further information on the permit development process.
CICWQ has worked for many years with the Regional Board, its members, staff, and public works agencies in the three-county area to consider specific changes to their existing MS4 permits. These changes would protect water quality and increase compliance flexibility for new and significant redevelopment projects within the Board’s jurisdiction. On July 3, CICWQ submitted a comment letter to the Regional Board, making these specific requests.
