Stormwater Management Development Plan Requirements
The Town's stormwater management regulations for development are found in the Land Use Management Ordinance (LUMO), Section 5.4 (see amendment modifying Section 5.4.2), and Section 5.19. These sections establish stormwater management requirements and controls for rate, volume, and quality. The following items are referenced in the LUMO requirements.
The Stormwater Impact Statementis a technical engineering report, and must be prepared by a NC Professional Engineer. It describes the existing conditions of a developable site and calculates the impacts that the development will cause to the existing conditions, including hydrology, flow patterns, soils, vegetation, and natural features such as streams and steep slopes. This report must be approved prior to receiving a Zoning Compliance Permit for the development.
The Stormwater Management Plan must be prepared by a NC Professional Engineer, and is also a requirement for the submittal of a Zoning Compliance Permit. In general, it includes a drawing of the new and proposed site topography, overlay districts, buffers, Resource Conservation District boundaries, building footprint, stormwater features, erosion control methods and landscaping. This plan must be approved prior to receiving a permit for the development.
Stormwater Easements All engineered stormwater management control, treatment, and conveyance structures located on or below the ground shall be wholly contained within an easement entitled: "Reserved Stormwater Facility Easement Hereby Dedicated" and shall be reserved from any development which would obstruct or constrict the effective management, control, and conveyance of stormwater from or across the property, other than the approved design and operation functions.
The Reserved Stormwater Facility Easement and the facility it protects are considered to be private, with the sole responsibility of the owner to provide for all required maintenance and operations as approved by the Town Manager.
The Reserved Stormwater Facility Easement and the Operations and Maintenance Plan are binding on the owner, heirs, successors, and assigns.
Design Manual and Standard Details
The Town uses technical specifications and standards in the Town’s Design Manual and Standard Details and in the North Carolina Division of Water Resources (NCDWR) Stormwater Design Manual,* as amended, as the basis for stormwater review decisions and for determining the compliance with the stormwater management requirements contained in Section 5.4 of the Land Use Management Ordinance. Chapel Hill has an EXCEPTION to the bioretention design in the NC Stormwater Design Manual: In Chapel Hill, grassed bioretention cells, designed in accordance with NCDWR requirements, may be used for individual single-family projects; however, grassed cells must be sodded and the sod must not be grown in soil with an impermeable (clay) layer. The Town limits the sod types to zoysia, centipede, or bermuda grass.
If the specifications, standards, or guidelines for a particular device enumerated in one of the above design manuals is more restrictive or applies a higher standard than the other, the Town reserves the right to require use of the more restrictive specification, guideline, or standard.
Whenever an applicant proposes to utilize a practice or practices not designed and constructed in accordance with the criteria and specifications in the Town or NCDWR design manuals, the applicant shall have the burden of demonstrating that the practice(s) will satisfy the minimum water quality performance standards. In such instances, the applicant is encouraged to contact the Town staff well in advance of making a formal submittal to discuss the proposed alternatives desired in order to minimize the potential for delays in the permitting process.
Other Technical Resources: Construction Industry Compliance Assistance is a resource for compliance with many environmental regulations. Here you will find plain language explanations of environmental rules for the construction industry. Also provided are links to detailed information, including state regulations and other resources.