Urban runoff

{
  "id": "MLC-T-ENV-029297",
  "term": "Urban runoff",
  "field": "Environment",
  "term_source": "Urban Runoff",
  "definition": "1. The portion of precipitation, snowmelt, or irrigation water that does not naturally percolate into the ground or evaporate, but runs off the land into streams or other surface water. It can carry pollutants from the air and land into the receiving waters.\n\n2. Storm water from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters.\n\n3. Stormwater from city streets and adjacent domestic or commercial properties that may carry pollutants of various kinds into the sewer systems and/or receiving waters.\n\n4. Surface runoff from an urban drainage area that reaches a stream or other body of water or a sewer/channel. Urban watersheds include (1) the 405 Bureau of Census Metropolitan Statistical Areas (MSA) considered either urban or urban fringe, and (2) water entering these MSAs (surface and ground waters entering the MSAs from upstream or up-gradient sources, source waters supplying the MSA population, and rain or snow events). Adapted from: US EPA, Risk Management Research Plan for Wet Weather Flows, EPA/600/R-96/140, November 1996. The urban watershed is a subset of the total watershed. Unlike the total watershed, topology does not strictly define the urban watershed. The urban watershed will often have one or more flows entering from outside the urban watershed and may have multiple effluents. Because the urban watershed commonly has influent streams, the up-gradient conditions can strongly affect the water quality. An urban area may include more than one watershed. Based on population demographics, the location of the existing and future urban watersheds shifts with social structure. The national trends measured by the Bureau of Census will define these areas. Two prominent changes that are evolving are the shrinking urban core surrounded by the growing suburban population density and the increasing in near-coastal populations.\n\n5. Surface runoff from an urban drainage area that reaches a stream or other body of water or a sewer/channel. Adapted from: US EPA, Risk Management Research Plan for Wet Weather Flows, EPA/600/R-96/140, November 1996.",
  "subject": "Water",
  "references": [
    "Economic Benefits of Runoff Controls Glossary",
    "Aquatic Biodiversity Glossary; Terms of Environment",
    "Drinking Water Technical & Legal Terms",
    "Urban Watershed Management Research Terminology",
    "Urban Watershed Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/urban-runoff/"
}