Stormwater Management

Stormwater Management

As the Rocky Mount area has grown and become increasingly urban, the City has had to adapt and manage the impacts of this growth. Stormwater, whether affected by possible flooding, water pollution, or an aging infrastructure, is one of the issues that needs this kind of management.

To improve water quality in the Tar-Pamlico River Basin and to reduce flooding, the City of Rocky Mount has implemented certain design requirements for new development and redevelopment sites. These requirements are broken down into water quality and water quantity standards.

The City's water quality standards were adopted as a result of the Tar-Pamlico Nutrient Sensitive Waters Rule. This rule states in general that that total post development offsite nutrient loading must be 30% lower than the pre development loading. For new development, this translates into a total offsite loading of four pounds per acre per year of Nitrogen, and four tenths of a pound per acre per year of Phosphorous. These nutrient reductions are achieved through the use of Best Management Practices (BMP's) such as wet ponds, engineered stormwater wetlands, bio-retention cells, or restored diffuse flow through riparian buffers.

Water quantity standards were implemented in an effort to reduce nuisance flooding problems within the City and its Extraterritorial Jurisdiction. The City requires that pre-development run off rates be maintained after development for the 1-, 10-, and 25-year 24-hour storms. Again, this runoff control is achieved through the use of detention devices or BMPs.

The City has developed a Stormwater Design Manual (downloadable below) which outlines the design requirements for new development and provides guidance on the calculations and data required for approval.

Stormwater Utility

A Stormwater Utility is a funding mechanism to pay for the costs of providing stormwater management services. For billing purposes, the stormwater program will use the same staff resources and billing systems to charge developed property within the city, based on the impact of their property on the stormwater system. The greater the impervious surface area on your property, the more a property will be charged for stormwater management services. This creates a fair system where all city residents bear the stormwater management costs based on the demand placed on the system.


Single-family structures will be charged a flat fee of $5.00. Other developed property owners, such as businesses, industry, multi-family, and tax-exempt properties, will pay $5.00 per month for every 2,519 square feet of impervious surface on their property.

For information, contact our Stormwater Hotline at 252-972-1500.


Drainage Studies