What Is Stormwater?
Stormwater is excess rain that does not soak into the ground or become absorbed by trees and plants. Instead it runs off into storm drain pipes and flows, untreated, into streams. Most of Rockville's stormwater is a result of impervious surfaces, such as buildings, paved roads and parking lots, compacted soil or gravel, or any other surface that prevents rainfall from percolating into the ground. As the water runs over land, it picks up pollutants like oil, fertilizer, pesticides, pet waste and sediment. These pollutants impact a stream's water quality. As the stormwater increases in volume and speed, it causes stream bank erosion and dumps more sediment into the stream, which harms aquatic insects, fish and animals that depend on the stream for their food and habitat.

Learn how to prevent pollution from entering streams.

There are several ways the City of Rockville helps manage stormwater. The actions help to reduce flooding and protect private property, protect the environment and contribute to happier, healthier communities. 

SWM Utility Fee	Laws	Permitting
Enforcement	Streams & Watersheds	Maintenance
Chesapeake Bay Issues	Projects	Make a Difference