Agenda - 08-26-1991 - Laserfiche WebLink

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36 for the reservoirs. For the Falls Reservoir, the City's LIA covers a one square mile area on the Eno River near Old Oxford Highway. (See the Table 4: Watershed Protection Areas, Present and Proposed). For the Jordan Reservoir, the LIA covers a considerably larger area in the vicinity of the New Hope Creek tributary. This ten square mile area generally extends from Chapel Hill Blvd. on the north to I-40 on the south. The County's regulations define a Water Quality Critical Area and a Water Quality Basin Area. The Critical Area extends one mile from the normal pool elevation of the reservoir. The Basin Area extends throughout the remainder of the watershed where the watershed drains to lake waters classified as water supply (WS). In areas not draining to a WS- classified water, the Basin Area extends two miles from the normal pool elevation. The County has Critical Areas and Basin Areas around each of the four reservoirs in Durham County. The amount of land in each of these two types of areas for each of the four reservoirs is shown in Table 4. The City and County ordinances do not currently address the "run -of - river" intake on the Eno River, except where existing land use and zoning might coincidentally be similar to that required by the State rules. The City's emergency raw water intake on the Eno river was last used prior to the completion of the Little River Reservoir. Given the City's current water supply capabilities, this intake would only be used now in the case of a significant interruption of the water supply from either Little River or Lake Michie Reservoirs. However, the City may want to maintain this water supply capability for future use both in case of emergencies and for possible use in connection with the development of the Nelio Teer Rock Quarry at some point in the future as a water supply storage facility. B. Implications of Adopted Regulations and Proposed Classifications. Table 4 shows the geographic areas covered by present City and County regulations. In addition, the Table shows the extent of areas of Durham County covered by the EMC's proposed rules. Included here are watersheds for Lake Michie, Little River, the Eno River water intake, Falls Reservoir and Jordan Reservoir. As indicated earlier in this report, the EMC has proposed the classifications of WS-IV for the entire Falls and Jordan Reservoirs. This represents a change from the way that the reservoirs are presently classified. For both reservoirs, the portions of the reservoir closest to the water intake structures and dams are presently classified as a water supply source. However, the upper reaches of the reservoirs, i.e., the portions more distant from water intakes and dams, are.presently classified as B and C, indicating waters that are not appropriate for water supply. This recognizes several features about the Falls Reservoir. The Reservoir is long (18 miles) and is segmented by causeways for road and rail crossings, but connected by causeway openings. Therefore, in some ways the Reservoir performs like a "chain of lakes ", each with its own characteristics regarding pollution settling and transmission. Under the adopted EMC rules, Durham would delineate a Critical Area approximately one mile from the normal pool of the reservoirs or at the ridgeline, whichever is the shortest distance. Likewise, a Protected Area for the Falls and Jordan Reservoirs would be delineated approximately five males from the normal pool of the Reservoirs or at the ridgeline, whichever is the shortest distance. 8