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Stream Mapper

Welcome to Stream Mapper, the app where volunteers submit pictures and basic observations about local streams in
Howard County, Maryland.

Download the app to your mobile device to start exploring more than 757 miles of streams in our County.

About Stream Mapper

Stream Mapper is a crowd-sourced way to gather information about our local streams. Getting involved is as easy as downloading the app with your smartphone and logging your observations. By getting involved, you're providing a snapshot of your stream's health. The more we map, the more data there is to learn from.

647 Volunteers
300 Reports

Get to know your local stream

Did you know that everyone in Howard County lives within a 15-minute walk to a stream? It's true! We have small and large streams throughout our neighborhoods, schools, parks and businesses — find yours here. What we do every day affects them directly. Stream Mapper is a fun and interactive citizen-science project that has the added benefit of getting volunteers outside and exploring.

How does it work?

Using the app takes about 10 minutes. Simply visit a stream of your choice and follow the step-by-step instructions. You will make observations about the area in and around the stream. You can also report unusual conditions (think: odors, colors, etc.), trash, and invasive plants. Lastly, you will take at least two photos - one upstream and one downstream (we explain how to tell which is which in the app) and upload them.

Why should I use it?

The app is not only quick and easy to use, but can also help keep our streams clean. We take information that you report seriously. We have used the "unusual conditions" section to investigate illicit discharges and stop pollution at its source. One of our users also made us aware of a sewage overflow, which we were able to fix!

Users like you have also found cleanup sites using stream mapper reports and have taken over 3,700 pounds of trash out of local streams. All data from reports is available to the public right from this website. Browse reports and pictures or dig in and get more data.