Polluted Runoff

What Is Runoff?

Runoff is any water that flows across the surface of the land into a body of water. Runoff can flow into a ditch, a stream, a river or directly into an ocean or bay.

  • Runoff occurs when there is more water than the land can absorb, and the excess flows across the surface of the land directly into nearby creeks, streams or other water bodies.
  • Urbanization increases the amount of runoff.  Surfaces that are covered by buildings and hard surfaces like pavement do not allow rain and snow melt to soak into the ground. This greatly increases the volume and speed of stormwater runoff.  

Why Is Runoff a Problem?

Most developed areas rely on storm drains to carry runoff from roofs and paved areas to nearby waterways. Everything from our rooftops, roads, parking lots, driveways, yards, gardens and farms ends up in our rivers, streams and the Chesapeake Bay. This runoff is not filtered, and carries harmful pollutants, such as

  • chemicals, pesticides and fertilizers from yards, gardens and farms
  • viruses, bacteria and nutrients from pet waste and faulty septic systems
  • gas, oil, grease and toxic chemicals from motor vehicles
  • heavy metals (such as copper, lead and zinc) from roof shingles, motor vehicles and other sources

Consequences of Runoff

Polluted runoff makes our waterways unsafe for swimming, threatens Maryland seafood and causes localized flooding and property damage.

Unhealthy Waters

Polluted runoff carries harmful contaminants into our waters, resulting in water contact advisories and beach closures

Unsafe Seafood

Maryland seafood is iconic, but polluted runoff can lead to seafood consumption advisories and threaten our state’s maritime industry.

Flooding & Erosion

Runoff causes flooding and stream erosion, which can threaten private property and public infrastructure.


Solutions to Managing Polluted Runoff

Communities all across the country have successfully adopted programs that reduce pollution by reducing or managing runoff. There are multiple components to a successful program:

Sound Legislation

We need effective laws to ensure we are protecting our communities from the negative impacts of polluted runoff.

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Effective Regulation

All forms of pollution, including runoff, need strong regulation to ensure accountability and consistency.

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Laws and regulations are only effective if they are properly enforced. Citizens and governments must be watchdogs.

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The Center for Watershed Protection recently published a report on model laws that help manage polluted runoff. “The Value of Stormwater Fees in Maryland” underscores the need for the three components above.

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  • Land use
  • Climate: Heavy rainfall is very likely to become more frequent as the climate changes, leading to more runoff , etc.