Water Supply Watershed Protection Program
Frequently Asked Questions: Understanding the Density Averaging Provision
What is Density Averaging of Noncontiguous Parcels?
Density averaging involving noncontiguous parcels is based on the idea that the development plans for a pair of parcels can be submitted together and treated as a single development project for purposes of regulation. The amount of development allowed for the paired parcels taken in tandem cannot exceed the amount of development that would be allowed if the parcels were developed and reviewed separately for compliance with water supply watershed protection regulations.
Density averaging is an option that is available to local governments through the water supply rules (15A NCAC 2B .0104(u). Prior to approval of the density averaging ordinance amendment, the local government must demonstrate to the Water Quality Committee (WQC) of the Environmental Management Commission (EMC) that (1) the provisions meet or exceed the state's minimum requirements and (2) a mechanism exists to ensure the orderly and planned development potential throughout the watershed jurisdiction. Local governments must be able to demonstrate that they can administer the Density Averaging of Noncontiguous Parcels provision when submitting their ordinance amendment to the WQC for approval. The local government must be able to document that it is sufficiently staffed and financially and technically capable of implementing the provision.
A parcel pair used for averaged-density development must be located in the same water supply watershed and preferably within the same drainage area of the watershed. Paired parcels do not need to be located within the same portion of the water supply watershed (for example, both within the Protected Area); however, a local government may find it administratively easier to include such a restriction. Both parcels of the paired parcel cannot be located in the Critical Area. If one of the parcels is located in the Critical Area, that parcel shall not be developed beyond any existing development that may already be present. The purpose of this provision is to preserve open space in the more sensitive areas of the watershed such as the Critical Area.
If a local government decides to allow for density averaging of noncontiguous parcels, they must modify their ordinance to meet or exceed the minimum criteria established by the WQC, resubmit their ordinance for review and receive permission from the WQC prior to implementation.
The model ordinance amendment is intended to serve as criteria for local governments who may choose to implement density averaging. The density averaging rule is not explicit. Without such criteria staff and the WQC do not have a basis from which to judge the adequacy of a local government request to implement density averaging.
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Minimum Criteria to be Implemented by Local Government
- Parcel pairs being submitted for approval under this provision shall be submitted for development approval as a single unitary proposal.
- Overall density of the paired parcel averaged-density development, calculated either by dwelling units per acre or built-upon area, shall not exceed the density that would be allowed if the parcels were developed separately. The parcel pair shall be located in the same water supply watershed and preferably in the same drainage area of the watershed. Parcel pairs may be located in the Critical Area and in the Protected Area (or Balance of Watershed). However, if one of the parcels is located in the Critical Area and one is located in the Protected Area (or Balance of Watershsed), the Critical Area parcel shall not be developed beyond those densities allowed in the critical area provisions of the rules. The purpose of this provision is to preserve open space in the more sensitive areas of the watershed.
- The paired parcels in a paired parcel averaged-density development may include or be developed for single-family or multi-family residential development or non-residential development.
- Buffers shall at least meet the appropriate minimum statewide water supply watershed protection requirements on both parcels in the parcel pair according to the density of development occurring on each parcel.
- Built-upon areas on the parcels shall be designed to: 1) Minimize stormwater runoff impact to the receiving waters by minimizing concentrated stormwater flow; 2) Maximize the use of sheet flow through vegetated areas; 3) Minimize impervious surface areas; and 4) Locate development away from surface waters and drainageways to the maximum extent practicable.
- The portion of the parcel(s) which is not developed as part of the paired parcel, but that is being averaged in the land area being evaluated to meet the built-upon surface area, shall remain in a vegetated or natural state and be placed in a permanent conservation easement granted under G.S. 121-35 to the [county][town] or a land conservation organization.
- A Special Use Permit shall be obtained from the Watershed Review Board to ensure that both parcels considered together meet the standards of the ordinance and that potential buyers have notice of how the watershed regulations were applied to the parcel pair. Only the owner(s) of both of the paired parcels may submit the application for the Special Use Permit. A site plan for both of the parcels must be submitted and approved as part of the Special Use Permit. If such a permit is granted, no change in the development proposal authorized for either parcel shall be made unless the permit is amended. Upon issuance of such permit, one copy will be forwarded to DWQ. Included with the Special Use Permit will be a site plan, registered plats for both properties, a description of both properties, and documentation reflecting the development restrictions to the parcel pair that will remain undeveloped.
- The conservation easement shall be recorded in the deed for the parcel to which it applies. The Special Use Permit shall be recorded in the deed for each of the parcels in the parcel pair. Both the easement and the permit shall be noted on the subdivision plat or site plan that applies to each of the parcels.
- Paired parcel averaged-density developments that meet the low-density option development requirements shall transport stormwater runoff from the development by vegetated conveyances to the maximum extent practicable.
- No parcel for which a watershed variance has been granted, or would be required, may be included as part of a parcel pair.
- The development proposal for the parcel pair shall be consistent with the orderly and planned distribution of development throughout the watershed.
- The Watershed Review Board shall make written findings supported by appropriate calculations and documentation that the paired parcel averaged-density development plan as a whole conforms to the intent and requirements of this Article and Section, and that the proposed agreement assures protection of the public interest and achievement of the objectives of this Article.
If the following apply, include in the ordinance:
- Stormwater runoff from paired parcel density-averaged development which meet the high-density option development requirements shall be controlled on the parcel(s) where the high-density development is occurring in accordance with the criteria specified in the applicable Section of the [county][town] Watershed Protection Ordinance for high-density development.
- The 10/70 provision does not apply in the Critical Area of water supply watersheds. The built-upon surface area of the parcel(s) that fall within the Balance of Watershed or Protected Area cannot exceed 70%.
When Density Averaging is Utilized by a Local Government, the Following Definitions Should Be Incorporated into the Local Water Supply Protection Ordinance:
- Paired-parcel averaged-density development: A development proposal that includes a parcel pair meeting the development standards of this Article and Section and that qualifies for local development approval under the density-averaging provision of 15A NCAC 2B .0104(u).
- Parcel pair: Two noncontiguous parcels of land under the same or separate ownership, or two contiguous parcels of land under separate ownership, the development plans for which have been submitted in tandem so as to qualify for density averaged development permission under this Section.
- Developed parcel: Any parcel of a parcel pair that, under any approval granted under this part, may be developed to a development density or intensity that exceeds the maximum development density or intensity that would apply to the parcel if the paired-parcel averaged-density development option were not available.
- Undeveloped parcel: Whichever parcel in a parcel pair is not the developed parcel.
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