Urban Runoff Requirements for Development

Standard Urban Stormwater Mitigation Plan (SUSMP)/Water Quality Management Plan (WQMP)

One of the most important responsibilities of the City of Dana Point is to provide adequate decision making procedures to process and approve new development and redevelopment projects that occur within the City’s boundaries. This ensures that both development and redevelopment projects occur in an organized manner that reflects the vision and needs of the community, assesses the environmental issues associated with the proposed changes and provides a regulatory framework to ensure that standards set by the City are implemented. The City of Dana Point’s Standard Urban Stormwater Mitigation Plan (SUSMP), also known as the Water Quality Management Plan (WQMP) has been developed to address these issues.

During project review, approval, and permitting, the City shall require new development and significant redevelopment* projects to address the quality and quantity of storm water runoff through the incorporation of permanent (post-construction) BMPs in project design.  The goal for use of the SUSMP (City WQMP) is to achieve practicable and enforceable policies to minimize the effects of urbanization on site hydrology, urban runoff flow rates or velocities and pollutant loads.  This goal may be achieved through site-specific project-based controls, or a combination of project-based and offsite shared BMPs.

Projects subject to SUSMP requirements include:

• Residential development of 10 or more units
• Industrial and Commercial development greater than 100,000 square feet, including parking areas
• Automotive repair shops
• Restaurants (if greater than 5,000 square feet)
• Hillside development greater than 5,000 square feet
• impervious surface of 2,500 square feet or more located within, directly adjacent to (within 200 feet) or discharging to receiving waters within Environmentally Sensitive Areas
• Parking lots > 5,000 square feet or > 15 parking spaces and potentially exposed to urban runoff
• Streets, roads, highways, and freeways which could create a new paved surface that is 5,000 square feet or greater.

Exclusion: Trenching and resurfacing work associated with utility projects are not considered priority projects subject to SUSMP requirements.

* “Significant Redevelopment” means development that would create or add at least 5,000 square feet of impervious surfaces on an already developed site.  Significant redevelopment includes, but is not limited to: the expansion of a building footprint; addition to or replacement of a structure; replacement of an impervious surface that is not part of a routine maintenance activity; and land disturbing activities related with structural or impervious surfaces.  Replacement of impervious surfaces includes any activity that is not part of a routine maintenance activity where impervious material(s) are removed, exposing underlying soil during construction.  Significant redevelopment does not include trenching and resurfacing associated with utility work; resurfacing and reconfiguring surface parking lots; new sidewalk construction, pedestrian ramps, or bike lane on public and private existing roads; and replacement of damaged pavement.

Through the use of a Project Priority Determination Worksheet, the City categorizes a project as either a Priority Project or a Non-Priority Project. Depending upon its categorization, the project proponent is notified of the requirements for their project with respect to water quality. The Cityrequires project-specific Water Quality Management Plans (WQMPs) WQMP Template, as part of the development plan and entitlement approval process or the ministerial permit approval process, for all private and public projects that qualify as one of the Priority Project categories, regardless of project size.

To assist the project proponent in meeting the requirements of a Priority Project and preparation of a WQMP, the City has developed a WQMP Checklist and provides the following references to aid in the design and development of the WQMP.

Resources for Site Design, Source Control and Treatment Control BMPs

• California Stormwater Quality Association (CASQA) BMP Handbook for Development and Redevelopment, www.cabmphandbooks.com.
• Start at the Source (1999) – permeable pavements, alternative driveways presented. Bay Area Stormwater Management Agencies Association, 2101 Webster Street, Suite 500, Oakland California, 510-286-1255.
• Better Site Design: A Handbook for Changing Development Rules in Your Community (1998), Center for Watershed Protection, 8391 Main Street, Ellicott City, MD 21043, 410-461-8323, www.cwp.org.
• International Stormwater BMP Database, www.bmpdatabase.org.
• The Stormwater Manager’s Resource Center.  This is a comprehensive site with information on BMP design and sizing.  http://www.stormwatercenter.com.
• Reference Guide for Stormwater Best Management Practices (July 2000) City of Los Angeles, Urban runoff Management Division, 650 South Spring Street, 7th Floor, Los Angeles, California 90014, www.lacity.org/san/swmd/