Polluted Runoff

Residential stormwater runoff. Photo © 2010 Krista Schlyer/iLCPPolluted runoff in a residential neighborhood flows into a storm drain during a heavy rainfall. Photo © Krista Schlyer/iLCP

The Gray Funnel of the Chesapeake

As water flows off of our streets, parking lots, and building rooftops, it picks up all kinds of pollutants like pet waste, sediment, fertilizers, pesticides, oil, and automotive fluids. If it does not evaporate or soak into the ground—nature's "green filter"—and if untreated or poorly treated, the contaminated runoff adversely affects water quality and aquatic life in local streams, the rivers into which they feed, and ultimately the Chesapeake Bay. As more houses, roads, and shopping centers are built, more of this polluted stormwater or runoff makes its way through gutters and storm drains to the nearest stream.
Graphic showing how the landscape works as a green filter, removing pollution as rainwater sinks into the ground.

Urban and suburban polluted runoff is the only major source of nitrogen pollution in the Bay still growing. Though responsible for greater percentages of pollution, agriculture and sewage treatment plants have made progress. Better stormwater management is an increasingly necessary—but admittedly expensive—proposition for local governments.

As impervious surfaces channel large quantities of rainwater into streams at high velocity, the runoff wreaks havoc. The flow scours stream banks, destabilizes stream contours and alters depths. It muddies drinking water sources and also carries bacteria, making the treatment and use of such water more expensive.

In the Bay's tributaries, eroded material and dirt from the land become suspended in the water, blanketing aquatic habitat. This sediment keeps sunlight from reaching underwater grasses. As these plants die, the animals that rely on them are imperiled.

And it is not only wildlife that is endangered by stormwater pollution. The state of Maryland, for example, cautions people not to swim in waterways for 48 hours after a heavy rain. Stormwater carrying bacteria has resulted in serious illnesses. In urban and suburban areas where ground surfaces have been hardened and the polluted water has no place to go, local streets and basements often flood, causing repeated and costly damage to homes and businesses.

According to the Environmental Protection Agency (EPA), urban and suburban stormwater is the source of about 15 percent of the total nitrogen entering the Bay, and is the only source that is still increasing. In some rivers it makes up an even higher percentage of the problem. It is one of the major reasons that the Bay remains on EPA's "dirty waters" list and is now subject to the Chesapeake Clean Water Blueprint.

Additional information about stormwater management can be found at the following websites:

The Center for Watershed Protection
Low Impact Development Center
Low Impact Development Urban Design Tools

Cover: CBF 2014 Polluted Runoff Report

CBF's investigative report Polluted Runoff: How Investing in Runoff Pollution Control Systems Improves the Chesapeake Bay Region's Ecology, Economy, and Health details the problems created by suburban and urban runoff pollution. And it offers steps that local, state, and federal governments can take to reduce pollution and achieve clean water for local streams, rivers, and the Chesapeake Bay.

Download it today [pdf]

From the CBF Blog


You may also be interested in:
  • Community Solutions to Addressing Polluted Runoff There are several proven strategies communities can implement to absorb runoff and reduce the risk of routine flooding and damage from polluted runoff.
  • Runoff: A Growing Threat Urban and suburban runoff is the only major source of pollution that is growing in the Chesapeake Bay and its rivers and streams.
  • The Story of Nitrogen How excessive nitrogen and phosphorus degrade the Bay's water quality.
  • Construction Solutions to Polluted Runoff The best strategy for reducing runoff pollution combines the following four elements: prevention (planning and zoning); design, construction, and post-construction; enforcement, and permits.
  • Runoff: A Growing Threat Urban and suburban runoff is the only major source of pollution that is growing in the Chesapeake Bay and its rivers and streams.

In the News

05.18.15 - Environmentalists speak in support of bill to redo city's forest code

04.19.15 - Repeal of 'rain tax' requirement yet to trickle down to most area homeowners

04.17.15 - Faith & Values: Dreaming green brings a rain garden

04.15.15 - Chesapeake Bay's surprising wins

04.15.15 - Talbot should support roadside ditch program

04.14.15 - Still a 'rain tax' by any other name?

04.14.15 - Council opts for reason on stormwater

04.14.15 - Rain tax repeal enacted; lone legislator says bill repeals little

04.13.15 - CBF Press Release Eleventh Hour Passage of Stormwater Bill Caps Remarkable Session for Bay

04.13.15 - CBF Press Statement House of Delegates Strengthens Maryland Stormwater Law

04.13.15 - Talbot County should fund ditch project

04.09.15 - Stormwater fee bill unloved, but deserves backing

04.07.15 - Talbot County Ditches Can Help Save the Bay

04.07.15 - Court faults state oversight of storm-water cleanup efforts

04.02.15 - Miller Gets it Right on 'Rain Tax' Repeal

04.01.15 - Pilot ditch project starts in Royal Oak

03.25.15 - Bipartisanship efforts yield improved 'rain tax'

03.20.15 - City leaders doing right by business, clean water

03.18.15 - CBF Press Release Joint Environmental Statement on Hogan Administration's Revised Phosphorus Regulations

03.16.15 - Poll finds Marylanders confused over 'rain tax'

03.11.15 - Scientists: Road salts can harm water resources

03.04.15 - Hucker to Testify Against Bill to Repeal State's Stormwater Management Protection

03.03.15 - Alison Prost: Don't Backtrack on the Bay

03.03.15 - Video Rain Tax Hearing Gets Stormy in Annapolis

02.24.15 - Audio available "Rain Tax" Repeal: Campaign Fodder But a Budget Headache

02.17.15 - Prost: "Rain Tax"

02.16.15 - Clean-water advocate will be first speaker in nature series

02.15.15 - Audio available "Rain Tax" Repeal Brings Debate, Possible Lawsuits

02.11.15 - Video Promise kept: Gov. Larry Hogan's bill would repeal rain tax

02.10.15 - Larry Hogan aims to kill Martin O'Malley's 'rain tax'

02.10.15 - Gov. Hogan: No more taxing the rain

02.10.15 - Hogan unveils bill to repeal 'rain tax'

02.10.15 - Maryland Gov. Larry Hogan wants to kill the hated 'rain tax.' But can he?

02.10.15 - CBF Press Statement Governor's Stormwater Repeal Bill Would Take State Backwards

02.09.15 - President Barack Obama's budget is mixed for Chesapeake Bay

01.25.15 - Counties reconsider stormwater fees

01.21.15 - Counties aren't waiting for Larry Hogan to take on the 'rain tax'

01.20.15 - Audio available Chesapeake Bay Foundation Challenges Stormwater Permits

01.20.15 - Environmental group prepares legal challenge to Frederick County's stormwater permit

01.17.15 - Baltimore County plan would cut stormwater management fee

01.09.15 - Report on bay deserves attention

01.05.15 - Mr. Hogan picks the wrong 'first fight'

01.03.15 - PMT: the right thing to do—right now

12.19.14 - Concrete, Informed Solutions, Not Rhetoric Are Needed

12.09.14 - It Is Easy To Be Green

11.30.14 - Who can do the most for the Bay?

11.25.14 - New fee to pay for Salisbury stormwater fixes

11.19.14 - O'Malley moves on poultry phosphorus pollution

11.18.14 - Storm Water Drainage Fee the Topic at Salisbury Roundtable

11.17.14 - CBF Press Release Ten Years of Study is Enough to Wait

11.17.14 - Phosphorus rules pushed before Gov. O'Malley's exit

11.17.14 - O'Malley pushes PMT forward

10.28.14 - CBF Press Release CBF Issues Statement Following Gov. Corbett's Signing of the Buffer Bill

10.26.14 - Governor signs bill ending buffer requirement for PA’s cleanest streams

10.16.14 - CBF Press Release CBF Calls on Governor Corbett to Veto HB1565 - Bill that Will Pollute Pennsylvania's Waterways

10.14.14 - Ellicott City students join Gov. O'Malley on stream restoration project

10.14.14 - Video $1.7M Little Patuxent River Restoration to Help Trap Pollutants

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