Stormwater management facilities are designed to collect and control runoff from precipitation that falls on the land. Many of these are ponds, but other types of stormwater management facilities include underground storage structures, usually located under parking lots in commercial areas, and curbside inlets that remove oil and grit from storm water runoff. Currently, there are over 13,000 active stormwater management facilities located throughout Howard County.

stormwater pond feature

Why do we need to manage stormwater?

We need to manage stormwater because development removes wooded and grassed areas and replaces them with roads, homes and businesses. Stormwater is not able to percolate into these impervious structures and cannot flow naturally into the nearby rivers and streams. Instead, development increases the flow and force of stormwater thus resulting in increased and unnatural flows into our stream banks. This can lead to erosion, damaged wildlife habitats, and flooding.

Stormwater Management Facility Maintenance

With proper stormwater management, rain water is directed into a local stormwater management structure where it is stored and slowly released into our nearby streams. As stormwater is stored in these structures, sediment and other pollutants have an opportunity to settle out, thus improving water quality.

Click the link below for a list of contractors providing stormwater management facility maintenance.

micro-bioretention cropped

Frequently Asked Questions


How often does the County inspect my stormwater management facility?


The County inspects stormwater management facilities every 3 years.


How much will it cost to maintain my stormwater management facility?


The cost can vary depending on the type of stormwater management facility. Routine maintenance such as mowing, trash/debris removal and landscaping may be less expensive than non-routine maintenance. Non-routine maintenance may include sediment removal or structural repairs such as pipe replacement. It is recommended to get several estimates from qualified contractors.


Who maintains a publicly owned pond?


Contact the Howard County Bureau of Highways.


What if my pond is covered with algae?


There are many stormwater management ponds in the county which permanently retain water by design to improve the region’s water quality. Some of these ponds may have algae or other aquatic vegetation. This vegetation may result from excessive nutrients, but algae and vegetation are not harmful, they are evidence that the pond is functioning as intended.

Please see the Howard County Guideline for Common Aquatic Plants, which will help identify aquatic plants you may observe in your community pond or lake. If you are concerned about aesthetic issues related to vegetation, the guideline identifies possible plant control methods, and explains the role plants play in pond ecology and the maintenance of water quality.

*Howard County does not treat publicly owned or maintained stormwater management ponds for algae and/or other aquatic vegetation.

If the stormwater management pond is privately owned and maintained, the owner may control the algae or aquatic vegetation with approved herbicides. Any application of herbicides or pesticides to any body of water must be in accord with State and local law. The contractor applying the herbicides must be licensed by The Maryland Department of Agriculture (410-841-5700), hold a Toxic Materials Permit from The Maryland Department of the Environment (410-537-3003), and comply with the provisions of MDE’s NPDES General Permit MDG87.

Improper application of herbicides or pesticides to any body of water may potentially result in an illicit discharge. For further information or to report an illicit discharge, please contact the Howard County Stormwater Management Division, Cynthia Alden.


What can I do about mosquitoes?


The Maryland Department of Agriculture should be contacted regarding concerns about mosquitoes. Please see ways to reduce risk.

In addition, please see fact sheet regarding West Nile Virus and Zika Awareness below.

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