Water: Polluted Runoff
Post Construction Controls
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Explore Model Ordinances
The management of stormwater runoff from sites after the construction phase is vital to controlling the impacts of development on urban water quality. The increase in impervious surfaces such as rooftops, roads, parking lots, and sidewalks due to land development can have a detrimental effect on aquatic systems. Heightened levels of impervious cover have been associated with stream warming and loss of aquatic biodiversity in urban areas. Runoff from impervious areas can also contain a variety of pollutants that are detrimental to water quality, including sediment, nutrients, road salts, heavy metals, pathogenic bacteria, and petroleum hydrocarbons.
The main goal of the model post-construction stormwater management ordinance for existing development is to limit surface runoff volumes and reduce water runoff pollution loadings. There are other ideas that can be included in an ordinance to improve its ability to control stormwater runoff. The ordinance could include what nonstructural and structural stormwater practices are allowed within the community. Communities may also wish to add language regarding on-site stormwater requirements and whether off-site treatment is an option. The following example ordinances include language dealing with each of the issues above and communities should examine each ordinance for the language that is appropriate for their stormwater program.
- Maryland Department of the Environment Stormwater Management Regulations (PDF) (83 pp, 371K)
- Grand Traverse County, Michigan Soil Erosion and Stormwater Runoff Control Ordinance (PDF) (29 pp, 66K)
This ordinance addresses both construction and post-construction runoff control and maintenance easements for stormwater facilities.
- City of Seattle Stormwater, Grading and Drainage Control Code (PDF) (52 pp, 193K)
A comprehensive ordinance that deals with many of the issues of stormwater management, including language on administration and enforcement considerations.
- St. Johns River Water Management District, Florida—Environmental Resource Permits (PDF) (33 pp, 103K)
Regulation of Stormwater Management Systems A good example of a regional approach to stormwater management in a state where development pressures are extremely intense.
- City of Santa Monica, California Municipal Code of Ordinances—Urban Runoff Pollution (PDF) (9 pp, 63K)
This ordinance is noteworthy for its language on non-structural BMP requirements such as pollution prevention programs and good housekeeping practices.