Agenda - 06-26-2007-6e - Laserfiche WebLink

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la the edge of the FEMA mapped floodplain, if present, and not the stream bank), and protection of riparian buffer lands and floodplains are among some of the many watershed protection techniques Orange County uses in this and other watersheds in our jurisdiction. The reason for this long-standing policy is a fundamental belief that addressing water quality protection at the source by limiting nutrient loading at the outset is preferable to relying on structural controls after the fact. The portions of the Jordan Lake watershed in Orange County reflect this proactive approach to water quality protection. Within the Upper New Hope Arm of this watershed, Orange 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 (part of Morgan Creek) has, since 1989, included a minimum lot size of five-acres for each new lot, with impervious surfaces limited to as little as 4% in some 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 Carrboro, is part of an area known as the "Rural Buffer," which has two-acre minimum lot sizes and over 2,000 acres of protected land. This protected land also includes over 7,000 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. Orange County also enforces flood damage prevention regulations, which supplement stream buffer standards. Both of these prohibit any new structures or septic drain fields near surface water bodies. As an example of the effects of Orange County watershed standards, our staff has used an adaptation of the Upper Neuse Basin Site Evaluation Tool (SET) for a recent development in the University Lake watershed. On an 80-acre site with a natural nitrogen-loading rate of 0.66 pounds per acre per year, unrestricted development would produce an estimated 5.17 pounds per acre per year. Orange County regulations dropped that estimated nitrogen loading rate to 1.81 pounds per acre per year. Larger lot sizes required in this watershed appear to be the primary cause.