watershed home
Frequently Asked Questions
The Watershed Protection/Stormwater Management Section is responsible for the Watershed Protection Program for Guilford County's nine (9) drinking water supply watersheds. Below please find some of our most frequently asked questions.
Please select from the links below to view the corresponding answer.
  What is a watershed?

Watersheds are areas encompassed by nature’s boundaries in which the surface runoff flows to water supply reservoirs, by way of surface flow, streams, and creeks.

2.   What is the difference between a General Watershed Area and a watershed Critical Area?

Watershed Critical Areas cover the most sensitive portion of the watershed adjacent to a water supply intake or reservoir where risk associated with pollution is greatest. The General Watershed Area covers the remainder of the Watershed draining to the reservoir or intake.

3.   What is built-upon area? How do I calculate percent built-upon area?

Built-upon area is the portion of a property that is covered by impervious or partially impervious surface including buildings, pavement, gravel, and recreation facilities. To calculate built-upon area add the square footage of all surfaces covered by building, asphalt, gravel, concrete and divide by area of the tract of land.

4.   Is a gravel drive considered built-upon area?

Yes. Gravel is considered to be an impervious material.

5.   What is a tier?

Tiers are areas within the Watershed Critical area. Their distance from normal pool elevation of a reservoir determines each of the four tiers. Each tier has it’s own development standards.

6.   What is a BMP?

A BMP or Best Management Practice is a structural or nonstructural practice used to reduce nonpoint source pollution to receiving waters in order to achieve water quality protection goals.

7.   What is the difference between low-density and high-density?

Low-density expresses that development density or intensity that does not exceed certain limits established in the Water Supply Watershed Protection Rules. High-density development exceeds the limits, thereby requiring for engineered stormwater controls in conformance with the requirements of the Water Supply Watershed Protection Rules.

8.   Who maintains my drainage easement?

Maintenance of drainage easements is the responsibility of the property owner.

9.   What is a stream buffer?

Stream buffers are natural or vegetated areas through which stormwater runoff flows in a diffuse manner so that the runoff does not become channelized and which provides for infiltration of the runoff and filtering of pollutants.

10.   Is my property located in a water supply watershed? Which one?

To find out if your property is located within a watershed please call Guilford County Planning and Development or click on link to view watershed map.

11.   Why be concerned about stormwater?

Water pollution hurts everybody. Sediment is one of the top 3 pollutants in the state. Reducing flooding problems is a by-product of water quality management.

12.   Can I build in a drainage easement?

No. Exceptions are made for minor encroachments such as driveways and utilities.

13.   What is a floodplain?

Floodplains are the flat or low areas adjacent to the channel of a river, stream, or watercourse, lake or other body of standing water, which has been or may be covered by floodwater.

14.   How do I get a floodplain certificate for a home mortgage?

Floodplain certificates for a home mortgage can be obtained by contacting a professional land surveyor. Many mortgage companies rely on national certification companies to determine floodplain location.