Watershed Protection

Regular maintenance is crucial to ensure that a water quality device effectively removes stormwater pollutants. Pursuant to Chapter 15, Article II,  Subsection 9 of the Guilford County Development Ordinance, engineered Stormwater Control Measures (SCMs) must be inspected annually and the county is required to record the results and notify the responsible property owner or owner’s association when maintenance or repairs are necessary. Upon inspection, if repairs are needed, the responsible party is given 90 days to make the necessary improvements. The Guilford County SCM Design Manual and the Stormwater Watershed Protection/Stormwater Management Manual provide general design guidelines for major SCMs and recommended maintenance schedules.

The Guilford County Planning and Development Department revised the Development Ordinance to comply with the post-construction site runoff control requirements of NPDES Phase II stormwater regulations. Guilford County continues to implement the following post-construction stormwater management practices and strategies:

• Watershed development plan review;
• Require alternate and engineered stormwater controls for development and redevelopment as defined in Chapter 15, Article II, Subsection 9 of the Guilford County Development Ordinance;
• Require and enforce stream buffers;
• Conduct structural stormwater SCM inspections;
• Implement and enforce Chapter 15, Article II, Subsection 9 of the Guilford County Development Ordinance.

The Watershed Protection and Stormwater Management Section is responsible for the annual inspection of all SCMs located within the unincorporated limits of Guilford County. Staff maintain an inventory and inspection schedule for the SCMs. Examples of typical deficiencies found during the SCM inspections include overgrown vegetation, trees on dam embankment, lack of sufficient ground cover, erosion, and non-functioning SCMs. The Watershed Protection/Stormwater Management Section works with the responsible parties to ensure that the required maintenance is performed. The non-compliant water quality devices are brought before the Board of Commissioners for enforcement on an as needed basis.

SCMs are implemented to mitigate the impact of land use changes on the quantity and quality of stormwater runoff. There are a variety of SCMs available; selection typically depends on site characteristics and pollutant removal objectives. These devices include wet detention ponds, bio-retention areas, sand filters, stormwater wetlands, permeable pavement, rainwater harvesting systems, proprietary devices, and level spreaders. 

Designed to reduce stormwater volume, peak flows, and nonpoint source pollution, SCMs use techniques such as evapotranspiration, infiltration, detention, filtration or biological and chemical actions. SCMs can also improve receiving-water quality by extending the duration of outflows in comparison to inflow duration (known as hydrograph extension), which dilutes the stormwater discharged into a larger volume of upstream flow.

SCMs must have annual, and sometimes more frequent inspection and maintenance to perform as intended. Maintenance includes hydrologic and water quality function, landscape functions, and consideration of impacts on human health and safety. Currently the county is tasked with inspecting 300 +/- SCMs throughout the un-incorporated areas and contracted townships with new projects coming under annual inspections within the next year. Maintaining SCMs in accordance with the operation and maintenance guidelines on an approved site plan is the sole responsibility of the property owner. Guilford County’s Unified Development Ordinance and the appropriate North Carolina Administrative Code requires the inspection of the permanent SCMs annually to ensure they function efficiently as designed and intended. Annual inspection reports are forwarded to property owners and/or associations for maintenance requirements. Any deficiencies noted in the future inspection reports must be addressed within 90 days of the date of the letter sent.

The Watershed Protection/Stormwater Management Section is responsible for the annual inspection of all structural water quality control devices located within the unincorporated limits of Guilford County. Staff maintain an inventory and inspection schedule for the stormwater control devices. Examples of typical deficiencies found during the SCM inspections include overgrown vegetation, trees on dam embankment, lack of sufficient ground cover, erosion, and non-functioning SCMs. The Watershed Protection/Stormwater Management Section works with the responsible parties to ensure that the required maintenance is performed. The non-compliant water quality devices are brought before the Board of Commissioners for enforcement on an as needed basis.