| |
|
|
|
|
| . |
What is Urban Storm Water?
Did you ever think about what happens to a raindrop that falls within
the Chesapeake Bay watershed? It may land on a tree or other vegetation
and evaporate in the hot sun. It may land on a farm field and soak into
the ground, or it may land on a rooftop, driveway or roadway and travel
down the street, into a storm drain. Any rainwater in an urban or suburban
area that does not evaporate or infiltrate into the ground, but instead
pools up and travels down hill is considered urban storm water runoff.
 Development
activities, such as clearing vegetation, mass grading, removing and
compacting soils, and extensive uses of impervious surfaces (such as
buildings, parking lots, and roadways), can increase the amount of storm
water runoff in the watershed. In urbanized areas, increased storm water
runoff can cause increased flooding, stream bank erosion, degradation
of in-stream habitat and a reduction in groundwater
quality.
Development not only leads to landscape changes but also to contamination
of storm water runoff by pollutants
throughout the watershed. Storm water runoff becomes contaminated as
it flows across the land and picks up pollutants such as nutrients,
sediment and chemical
contaminants from roadways, yards, farms, golf courses, parking
lots and other lands. This polluted storm water runoff travels through
storm drains into local waterways, and it may ultimately end up in the
Bay.
Why is Urban Storm Water Runoff Important?
Cities contribute a significant amount of nitrogen and phosphorus
to the Bay. Urban storm water runoff is responsible for about 16% of
phosphorus, 11% of nitrogen, and 9% of sediment loads to the Bay. Chemical
contaminants (such as metals) from urban runoff can rival or exceed
the amount reaching the Bay from industries, federal facilities and
wastewater treatment plants. Urban storm water runoff is responsible
for impairments in over 1,570 miles of assessed streams in the Bay watershed
and has caused flooding, streambank erosion and habitat and living resource
degradation in many areas throughout the watershed. Given projections
regarding urban and suburban growth and the increase in impervious surfaces
in the watershed, managing urban storm water runoff is an important
priority for the Bay Program to undertake to improve water quality and
restore vital habitats and living resources in the Bay.
How is Storm Water Managed?
 Until
recently, storm water managers have focused on controlling runoff quantity
to prevent flooding, with minimal attention paid to controlling the
quality of that runoff. The vast majority of land developed prior to
the early 1980's in the Chesapeake Bay watershed lacks storm water quality
controls. Today, most Chesapeake Bay watershed jurisdictions are placing
more emphasis on managing both storm water quantity and quality, using
new and innovative technologies to reduce runoff volume and pollutant
loads.
How Does the Bay Program Address Storm Water Management?
In 2001, the Chesapeake Bay Program adopted the directive "Managing
Storm Water on State, Federal and District-Owned Lands and Facilities"
to better manage storm water on government-owned lands and facilities,
which comprise more than 13 percent of the watershed. The jurisdictions
are working to meet the Directive’s commitments and they will
show how to prevent storm water problems in the face of increased growth
and development and how to remediate storm water problems on lands that
have already been developed, setting an example for local governments
and private landowners. In addition, the Urban
Stormwater Workgroup collaborates to address storm water management
issues in the watershed.
|
Federal, State and Local Programs:
Innovative Stormwater Management:
Reports and Fact Sheets:
Assistance for businesses, governments and communities:
|
To bookmark this page, please use this URL:
http://www.chesapeakebay.net/stormwater.htm
For more information, contact the Chesapeake
Bay Program Office:
410 Severn Avenue, Suite 109, Annapolis, MD 21403 / Tel: (800) YOUR-BAY
/ Fax: (410) 267-5777.
Terms
of Use | Privacy Policy
| Contact Us
Directions to the Bay Program Office
 
Last modified:
01/11/2006
|
|
