Stormwater Glossary of Terms
303 ( d ) Waterbody - A list of lakes , rivers , and streams that have been designated as impaired or threatened by a pollutant ( s ) for which one or more TMDLs are needed . Impaired means that the water is not meeting state water quality standards .
319 - The section of the Federal Clean Water Act that deals with nonpoint pollution .
Best Management Practice ( BMP ), nonstructural - Strategies implemented to control stormwater runoff that focus on pollution prevention such as alternative site design , zoning and ordinances , education , and good housekeeping measures .
Best Management Practice ( BMP ), structural - Engineered devices implemented to control , treat , or prevent stormwater runoff pollution .
Biofiltration - The use of vegetation ( usually grasses or wetland plants ) to filter and treat stormwater runoff as it is conveyed through an open channel or swale .
Bioretention - The use of vegetation in retention areas designed to allow infiltration of runoff into the ground . The plants provide additional pollutant removal and filtering functions while infiltration allows the temperature of the runoff to be cooled .
Buffer zone - A designated transitional area around a stream , lake , or wetland left in a natural , usually vegetated state so as to protect the waterbody from runoff pollution . Development is often restricted or prohibited in a buffer zone .
Catchbasin - An inlet to a storm or combined sewer equipped with a sediment sump , and sometimes a hood , on its outlet pipe to the sewer . Catchbasins can collect some of the sediment and debris washed off the streets , and help to provide a water seal against the venting of sewer gases . Catchbasins should be cleaned out regularly to function properly .
Catchment - See Watershed .
Combined sewer system - A sewer system that conveys stormwater runoff along with sanitary sewage and industrial waste .
Conveyance - The process of water moving from one place to another .
Detention - The storage and slow release of stormwater following a precipitation event . Detention is used for both pollutant removal , stormwater storage , and peak flow reduction . Both wet and dry detention methods can be applied .
Discharge - The volume of water that passes a given location within a given time period .
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