Low Impact Development | BIAW

Low Impact Development

Low Impact Development, or "LID," is a stormwater and land use management strategy that strives to mimic pre-disturbance hydrological processes of infiltration, filtrations, storage, evaporation and transpiration by emphasizing conservation and use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design. LID strategies can be applied to new development, urban retrofits, infrastructure improvements and revitalization projects to protect aquatic resources.

The new municipal National Pollutant Discharge Elimination System (NPDES) permits in Western Washington require use of Low Impact Development, where feasible. The Phase II Western Washington permit also requires the elimination of the 1-acre exemption, and for jurisdictions covered under this permit to remove impediments and to implement Low Impact Development in their land use and development codes, regulations and ordinances. Permits for Eastern Washington require allowing the use of Low Impact Development.

Western Washington Phase II and Phase I jurisdictions include 83 cities and 9 counties. Eastern Washington Phase II jurisdictions include 18 cities and 6 counties.

The deadline for Western Washington Phase II jurisdictions to implement the new LID requirements is based their Growth Management Act Comprehensive Plan Update timelines or December 31, 2016, whichever is later. Phase I jurisdictions are required to implement the new LID requirements by June 30, 2015.

Industry Fact Sheets

Low Impact Development Series Articles, Building Insight

Low Impact Development Resources

BIAW has assembled a variety of resources-articles, reports, links and references-to LID material available from other resources, as well as information and tools specifically developed by the Department of Ecology and partner organizations.

Top LID Websites

This site will continue to add links to a variety of resources regarding Low Impact Development, including manuals, guidance documents, articles regarding LID techniques, and Educational and Technical Training opportunities.