Large watersheds are areas that separate waters flowing to different rivers, basins, or oceans. Cuyahoga County is intersected by three major river watersheds: The Rocky River, Cuyahoga River, and Chagrin River watersheds.

In addition, much of Cuyahoga County drains directly to the shores of Lake Erie. Within those major watersheds are 32 smaller subwatersheds, ranging in size from 200 acres to more than 20,000 acres. Although they follow the natural contours of their respective drainage areas (as opposed to local community boundaries), these subwatersheds are characterized by varying degrees of urbanization and degradation. In a few subwatersheds, there is no significant above-ground drainage, while others benefit from extensive protection in the form of parks and conservation easements.

These subwatersheds are typically monitored and managed by local watershed stewardship groups, such as Big Creek Connects or Friends of Euclid Creek. Their Watershed Action Plans are key to a cleaner Lake Erie.

Existing and Potential Tree Canopy

Among the 32 subwatersheds, 15 exceeded the County average of 34.7% tree canopy. Those with the lowest canopy are within the most urbanized areas within and adjacent to downtown Cleveland, including several Lake Erie and Cuyahoga River drainage areas. Those that are below the County tree canopy average are typified by areas with high degrees of imperviousness and areas “not suitable for

Many subwatersheds with low to moderate canopy levels can be encouraged to realize higher canopy coverage by their availability of “Vegetated Area”, including Rocky River West Branch, Abrams Creek, Tinkers Creek, Euclid Creek, and Mill Creek.