The Model Water Quality Management Plan (WQMP) and Technical Guidance Document (TGD) provide guidance for “priority” new development and significant redevelopment projects to comply with the two National Pollutant Discharge Elimination System (NPDES) Phase I Municipal Separate Storm Sewer System (MS4) permits held jointly by the Orange County cities, unincorporated Orange County, and Orange County Flood Control District (collectively, Permittees).
Where is the proposed project located?
The following two sections detail program documents developed and managed by the County of Orange, as Principal Permittee, on behalf of the Permittees. Use the web app below to view relevant water quality requirements and guidance for proposed land development projects, given a particular location. Additionally, if your project is located in any of the 34 Orange County cities, please visit that City’s website to view jurisdiction-specific requirements, templates, and checklists. If your project is in unincorporated County, please visit explore OC Development Services' Water Quality web page.
North Orange County Project Guidance
In response to permit requirements from the Santa Ana Regional Water Quality Control Board (RWQCB), the following guidance documents have been prepared for proposed projects located in north and central Orange County (above El Toro Road):
South Orange County Project Guidance
In response to permit requirements from the San Diego RWQCB, the following guidance documents, collectively equivalent to the “BMP Design Manual”, have been prepared for proposed projects located in south Orange County (below El Toro Road):
A hydrologic model called the south Orange County Hydrology Model (SOCHM) has been developed to assist project proponents in selecting and sizing hydromodification control where applicable.
The following tools are available to assist project proponents:
- Contact the Help Desk explore with questions
- Training Modules
- OC Environmental Resources GIS Data Portal explore, which includes the WIHMP Data Map.