D. HISTORICAL SIGNIFICANCE

The 1-mile exclusion area includes the site of Old Pickens township, the structures of which, except for Old Pickens Church and one residence, were destroyed in 1868. The Director of the Pendleton District of the South Carolina State Historical and Recreational Commission supplied this information.

Lake Keowee floods an area that includes the site of Old Fort Prince George (an early British outpost) and the site of old Keoweetown (headquarters of the lower Cherokee Nation). Before the flooding, extensive diggings were made for archeological salvage at these two historical sites. The artifacts that were found are in the possession of state and local museums. This work was conducted by the University of South Carolina using a grant made by the applicant. An old covered bridge that crossed the Keowee River was moved and restored at Keowee-Toxaway State Park. In addition, all graves and cemeteries in the areas that were to be inundated were moved to new locations.

The area is drained by the Keowee and Little Rivers, which join some 7 miles below the site to form the Seneca River. The Seneca River is a major tributary of the Savannah River.

When the Seneca River was dammed to form the Hartwell Reservoir, water backed up into the lower Keowee and Little Rivers. The Keowee and Little Rivers, now separately dammed (Fig. II-3), form a single lake, Lake Keowee. These dams are about 160 feet high, and the impounded waters (Keowee Lake) furnish the energy to drive the Keowee hydroelectric power station. Lake Keowee is about 20 miles long and has a volume, when full, of about one million acre-feet. Upstream from Lake Keowee on the Keowee River will be the Jocassee Reservoir, with a 360-foot-high dam under construction, and a storage capacity of a little over one million acre-feet. The Jocassee Reservoir will be used for pumped storage, producing electricity during the day from water that is pumped back again into the reservoir at night.

Because of these various dams, lakes, and reservoirs, the natural flow of the rivers is greatly altered. Before the dams were built, the average flow of the Keowee River near what is now the upper end of Keowee Lake was 465 cubic feet per second. The minimum flow was 57 cubic feet per second, and the maximum was 21,000.

The combined flow of the Keowee and Little

Rivers 1 mile below their confluence, in what is now the upper part of the Hartwell Reservoir, was 1140 cubic feet per second; the minimum flow was 120, and the maximum 25, 200. With the creation of Lake Keowee, the maximum discharge into upper Hartwell Reservoir through the Keowee hydroelectric plant is 19,800 cubic feet per second; the minimum discharge attainable is 30 cubic feet per second. (Flow through Little River Dam is negligible.) The average discharge of Hartwell Reservoir is 4,400 cubic feet per second.

The Station is near the ridgeline between the Keowee and Little River valleys and is more than 100 feet above the maximum known flood in either valley. The dams on the lakes further reduce the possibility of a Station flood. The design discharge rate of the spillway for Lake Keowee is 105,000 cubic feet per second and for Lake Jocassee, 70,500 cubic feet per second.

In 1965 a sample of water from the Keowee River near what is now the upper end of Lake Keowee was analyzed by the U.S. Geological Survey as follows:

Specific Conductance 13.0 micromhos at 25°C (76°F)

Analyses of the lower Keowee River were made in 1953-1955 under varying conditions and are given in Appendix II-1. The water of Lake Keowee is essentially soft water; its average temperature varies from 50°F in January (the lake does not freeze) to 85.2°F in August.

The Station is in the drainage basins of the Little and Keowee Rivers, which receive the runoff of surface water and groundwater from the site. The residual soil in the area is comparatively impermeable, particularly in late winter and early spring when the soil is saturated, and much of the precipitation goes into direct surface runoff. The residual soils do accept some water and the area is underlain by a water table which is a subdued replica of the topography. Groundwater is not an important source of water supply in the area; all neighboring towns obtain their municipal supplies from streams. There are some 30 domestic and farm wells in the general area of the plant. Most are hand dug and are equipped with a bucket or jet pump. They are, for the most part, from 40 to 60 feet deep and yield less than 5 gallons per minute. A few drilled wells in the area obtain a little water from fractured bedrock but the most important source of groundwater is in the residual soil, which locally is as deep as 100 feet. The largest groundwater installation in the area is at the Keowee High School, 4 miles west of the site, which is supplied with water from a battery of eight wells.

The temperature of the well water varies from 46° to 59°F, although most of the readings are between 50° and 53°F. The groundwater is slightly acid, having a pH of from 5 to 6. No chemical analyses of the groundwater are available, but from the nature of the terrain it is reasonable to assume that it is a bicarbonate water with low total dissolved solids and of excellent chemical quality.

From measurements of the permeability of the residual soil, the rate of movement of the groundwater was calculated to be 150 to 250 feet per year. The residual soil has excellent ion exchange properties.

3. Meteorology

Available meteorological records include those from Clemson, South Carolina; the Greenville-Spartanburg Weather Bureau Station; Athens, Georgia; and other nearby stations. In addition, an onsite meteorological survey was conducted from October 1966 to October 1967.

One principal meteorological influence on the site is its location relative to the nearby Appalachian Mountains, which cause a channeling of surface winds. The meteorology of both the site and of the region is therefore rather well known. As a result, the wind rose (Fig. II-6) is bimodal, with maximum frequencies in the sectors north-northeast to east(2)" northeast and southwest to west.