What is a watershed?
Watersheds protect environmental health by collecting, filtering and storing water
A watershed is an area of land that drains to a common body of water, such as a nearby creek, stream, river or lake.
Image source: Heartland Conservation Alliance
How watersheds work
Sometimes known as drainage basins or catchments, watersheds are determined by topography because water always takes the path of least resistance, flowing downward due to gravity.
For example, when it rains, all the water from a small watershed may travel downstream to a local creek, like Mill Creek. That creek will flow into a larger stream, like Brush Creek, which collects water from an even larger watershed. Brush Creek flows into the Blue River, which then deposits water into the Missouri River.
Watersheds cross city and county lines – protecting them requires shared responsibility.
Where does the water go?
When homes, roads, and office buildings are built, natural vegetation is often removed and replaced with paved surfaces. These hard surfaces prevent rainwater from soaking into the ground, which is an important process for replenishing groundwater and keeping our drinking water sources clean. Infiltration also feeds underground springs and helps maintain healthy ecosystems.
Paved areas cause rainwater to run off quickly into streams, increasing erosion and damaging wildlife habitats. You can help by directing water from downspouts away from driveways and sidewalks whenever possible.
Understanding Combined Sewers
In many older neighborhoods, the same sewer pipes carry rainwater and wastewater from homes to treatment plants. During heavy rain, these systems can become overloaded and spill untreated water into nearby rivers and streams. This is called a Combined Sewer Overflow (CSO), and it can pollute water and harm fish and wildlife.
Replacing these sewer systems is costly, so many are still in use today. Homeowners can help by disconnecting downspouts from sewer pipes and directing rainwater to grassy areas, rain barrels, or rain gardens with native plants. These simple actions reduce the amount of rainwater entering the sewer system and help keep our waterways cleaner.
The Greater Kansas City Green Region Explorer
The Mid-America Regional Council offers an interactive map showing environmental resources and infrastructure across the region, including trails, parks, combined sewer overflow areas, and information on stream health, land use, land cover, and conservation priorities.
Explore the interactive nine-county map to learn more about local waterways and watersheds.
How to help your downstream neighbor
Here’s what you can do to help your downstream neighbor:
- Keep a water-wise yard
- Improve soil with natural amendments
- Pick up pet waste
- Keep storm drains clear
- Clean up contaminants from home projects
