Orange County NC Website
Watershed Critical Area Mapping Options 3 <br />11/14/2006 <br />Issues Relating to Mapping of the Upper Eno Critical Watershed Areas <br />The original 1994 zoning and watershed maps did not illustrate the associated zoning <br />text, which is typically the operative aspect of regulations. The maps do not reflect the <br />text for the following reasons: <br />Topographic mapping had less elevation refinement leading to more spatial <br />variation when trying to determine distances from existing or future watershed <br />impoundment sites and the associated normal pool elevation (NPE). For example, <br />the Lake Orange NPE is 615', but the Orange County topographic information, at <br />that time, only displayed the 610' and 620' topographic contours. We now have <br />five-foot topographic data available and can better interpolate the map buffer. <br />2. Some proposed impoundments, such as the West Fork of the Eno. River did not <br />have a determined NPE, so a map approximation was made. We now know the <br />proposed Phase 2 NPE is 634'. <br />3. Some impoundments half -mile buffers were shown on the map but the NPE that <br />established the area buffered was not described or unnamed in the zoning text. <br />For example, the proposed Eno River Impoundment above McGowan Creek was <br />map buffered but not named in the text. We can more accurately establish an <br />area buffer along the Eno River above Corporation Lake to protect the proposed <br />Eno River above McGowan Creek Reservoir at the 580' NPE. <br />4. Originally, the Lake Orange NPE was 614', but an additional one -foot of <br />freeboard was added. The official NPE is now 615'. <br />5. Lake Ben Johnson is not presently listed in the zoning text. We can map the <br />impoundment with its 515 " NPE accurately. <br />6. The original base maps are hand drawn on County cadastral maps. The map's <br />accuracy is not always reliable. The 1984 West Orange Study and 1987 Water <br />Supply Study base maps were hand -drawn on these cadastral maps. While as <br />accurate as possible at the time, the small -scale maps, which resulted, are not <br />accurate for large -scale property maps that developers use for platting. We have <br />digitized these maps and can refine the watershed boundary lines with state -of- <br />the -art watershed mapping provided by the State of North Carolina. <br />C; (`ctttpreitersi r .'ar;tit:g. 1):v"(1 I 'N­m�,N.Yxl .':k't? ":a TCrarir•. ;'. r 20 :1:'{ 1 [ pt t:; iSr. 'i'rxi AN xis'Aa:E ?r @: 01,6 011 Cnmpa E >E 3S.Ci> <br />