What Is a Watershed?
A watershed is all the land, surface water (lakes, streams, reservoirs, and wetlands) and underlying groundwater that drains to a given point (Figure 1). The word "watershed" can be used interchangeably with “drainage basin” or “catchment.” A watershed can be as small as a few square feet draining into a creek; or it could be large enough to encompass all the land that drains into a major river, estuary, bay or the ocean. Watersheds are like Russian nesting dolls – small watersheds that feed the smallest streams are part of larger watersheds that feed large rivers. For example, the Toms Creek Watershed is a subwatershed of the Morgan Creek Watershed, which is part of the Jordan Lake Watershed, which is part of the Cape Fear Watershed.
Figure 1 What is a Watershed?
For this reason, the water quality of a receiving water body is directly related to its watershed and the streams that drain it. The streamflow and water quality of the surface waters, and sometimes groundwater, are affected by what is happening, human-induced or not, in the watershed.
Each Carrboro resident lives in a watershed that flows to a local creek. See Appendix 2 for maps of local watersheds.
What Is a Water Supply Watershed?
A Water Supply Watershed contains surface waters used for domestic water supply, to be protected by specific development and water quality standards.
The University Lake Watershed is one of two water supply watersheds for Carrboro, Chapel Hill, and UNC. (Cane Creek, located farther west, is the other.) University Lake is fed by several streams that comprise the upper Morgan Creek watershed. Its water is pumped to the OWASA water treatment plant in Carrboro and then distributed.
The Jordan Lake Watershed is a Water Supply Watershed for several other communities. All of Carrboro drains into this much larger watershed that comprises the headwaters of the Cape Fear River Basin. It’s a regional water resource providing flood protection, water supply, and recreational benefits to people, and habitat for many aquatic and terrestrial species.
See Appendix 2 for maps of local watersheds.
What Watershed Do I Live In?
Carrboro contains the headwaters of the Bolin Creek watershed and is located near the headwaters of several other watersheds:
1. Morgan Creek to our west;
2. The New Hope Creek watershed to our north and east;
3. The Booker Creek watershed to our east in Chapel Hill joins Bolin Creek to form Little Creek.
Every Carrboro stream and its tributaries have their own watersheds. These include Morgan Creek and Bolin Creek, and tributaries like Toms Creek, Jones Creek, Buckhorn Branch, Jolly Branch, Dry Gulch, and Tanbark Branch (Appendix 2). New Hope Creek, Little Creek and Morgan Creek all join at the upper end of Jordan Lake, a reservoir formed by the damming of the Haw and New Hope Rivers.
Bolin Creek has been listed as an impaired waterbody by the State of North Carolina and the United States Environmental Protection Agency (EPA) since the early 2000s. This means the stream is not meeting its water quality standards and is failing to support its intended uses. Local, state and EPA government partners created the Bolin Creek Watershed Restoration Team to develop and execute a strategy for improving water quality and creek conditions. Since the land use in Bolin Creek is heavily residential, the collective actions many homeowners take on their lots have a big impact on the creek.