Agenda - 03-17-2015 - 7e - Laserfiche WebLink

Browse Search

BACKGROUND: In accordance with NC General Statute 143 Chapter 21, Orange County adopted watershed management standards in the late 1980's early 1990's establishing regulations to prevent significant future water quality deterioration in `existing or potential future drinking water reservoirs'. This included the adoption of impervious surface limits for properties designated as being located within either `protected' or 'critical' watershed areas. Impervious surface is defined within Article 10 Definitions of the UDO as: A surface composed of any material that impedes or prevents the natural infiltration of water into the soil. Such surfaces include concrete, asphalt, and gravel surfaces. These include, but are not limited to streets and parking areas, sidewalks, patios, and structures that cover the land. Large amounts of impervious surface on a parcel of property impacts water quality by limiting the availability of undisturbed natural area allowing for the infiltration and treatment of stormwater runoff. To address this issue, the County adopted limits on the total cumulative amount of impervious surface(s) that can be developed thereby encouraging the preservation of natural area and allowing for more on -site infiltration. Impervious surface limits vary based on a properties location within a Watershed Protection Overlay District. Please refer to Attachment 1 for a chart breaking down current impervious surface limits in each district. Please note there are no impervious surface limits on those properties not located within a `protected' or 'critical' Watershed Protection Overlay District. This includes areas north of Chapel Hill, around the Town of Hillsborough, and a portion of land area within the Bingham Township. For more information on the location of various overlay districts, please refer to Attachment 2. ISSUE: Staff and Board members have received numerous inquiries related to increasing allowable impervious surface area including: • Increasing allowable impervious surface percentages in Watershed Protection Overlay Districts, • Allow additional impervious surface area on property based on the installation of a stormwater feature, and • Exempt gravel from being considered an `impervious surface area'. The County already has procedures in place, specifically contained Section 4.2.8 of the Unified Development Ordinance (UDO), allowing for a property owner to modify the allowable impervious surface area for a parcel, specifically: a. Applying for a variance STAFF COMMENT: Obtaining a variance from existing impervious surface limits is extremely difficult as the property owner has to demonstrate there is a unique hardship on the property. b. Proposing the establishment of a conservation easement on an adjacent parcel of property. This conservation easement would allow for a defined area to remain in a natural, undeveloped, state while allowing for the transfer of the impervious surface area to the subject parcel to facilitate development.