Agenda - 03-26-2009 - 4a6 - Laserfiche WebLink

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4a-29 The portions of the Jordan Lake watershed in Urange County reflect this proactive approach to water quality protection. within the Upper New Hvpe Arm of this watershed, Grange County has instituted far-reaching land use or non-structural controls, as shown on the attached map. There are three sub-basins draining to the Upper New Hope Arm in the County's jurisdiction. The University Lake watershed apart of Morgan Creek~'has, since X989, included a minimum lot size of five-acres far each new lot, with impervious surfaces limited tv as little as ~°~~ in same cases. These measures were instituted after a comprehensive watershed technical study and extensive community dialogue. The Upper New Hope Creek basin, north of Chapel Hill and Carrbora, is part of an area known as the "Rural duffer," which hastwo-acre minimum lot sizes and over 2,4oa acres of protected~land. This protected land also includes over 7,ga4 linear feet of New Hope Creek in the County's jurisdiction. A small portion of Morgan Creek downstream of University Lake and south of Chapel Hill also has two-acre lot zoning, and significant protected lands. Grange County also enforces flood damage prevention regulations, which supplement stream buffer standards. Bath of these prohibit any new structures or septic drain fields near surface water bodies. As an exar~ple of the effects of Grange County watershed standards, our staff has used an adaptation of the Upper Meuse Basin Site Evaluation Tool SET} far a recent ~, development in the Un"rversity Lake watershed. Can an 8D-acre site with a natural nitrogen-loading rate of g.8fi pounds per acre per year, unrestricted development would produce an estimated 5.~1 pounds per acre per year. Orange County regulations dropped that estimated nitrogen loading rate to ~ .81 pounds per acre per year. larger lot sizes required in this watershed appear to be the primary cause. Grange County is ~-and has always been -very supportive of attempts to reduce nu~ient loading and protect water quality in Jordan Lake. However, the method of the proposed implementation for the non-point source rules in the Upper New Hope Arrn may not be practical or equitable for a rural jurisdiction, especially since significant protective measures have been instituted far many years. In particular, Orange County would like tv offer the following points for the Cornrr~issivn's consideration: ~ . Deductions for existing development are not ~petforrnance" based. a. The proposed reductions for nitrogen and phosphorus are represented as percentage loading reductions. This "one size fits ally approach does not acknowledge the very different loading rates and land use patterns between urban and rural portions of this area; nor does this approach take into consideration the resultant difficulty in achieving apercentage-based reduction by jurisdiction. . . b. As described above, Orange County already employs watershed protection measures that account for relatively low nutrient loading rates. In order to