Electrical Power for Valdez and the Copper River Basin-1981

pipeline and marine terminal. The population in 1969 was approximately1,000, grew to 8,000 in mid-1976 and steadied to 3,350 by 1979.Future population fluctuations will occur with the construction of AlaskaPetrochemical Company (ALPETCO) plant. During the construction phaseALPETCO will employ nearly 1,000 people and the operational phase willemploy over 700 persons.Table 2 ofworkforce.members ofdependentsthe main report presents employment estimates for the ValdezApproximately 35 to 40 percent of the Valdez population arethe 1abur force. This means there are approximately 1.5for every member of the workforce.4. Cu ltura 1 ResourcesThere are no cultural resources in the affected area of the Valdezhydropower project. The area had the potential of yielding prehistoricChugach Eskimo evidence because of the traaitiona1 land use of thesepeople in Prince William Sound. Historical events surrounding earlyValdez, such as Army exploration, mineral mining and settlement is veryrich. No remains, however, are left in the affected area. For a morecomplete account see Appendix F.D. ENVIRONMENTAL EFFECTS1. Physicala. General: The plans discussed in the report all utilize twomethods of power generation. Since the impacts associated with dieselgeneration already exist, no new diesel plants are proposed. Thehydroelectric project will have its own unique impacts on the environmentwhether associated with diesel or the Pressure Reducing Turbine. Forreasons of clarity and continuity, the impacts of the hydroelectricproject and the Pressure Reducing Turbine will be discussed separately.b. Hydrology and Water Quality:Hydroelectric Project: The proposed laKe tap would withdraw waterfrom a depth of 117 feet below the existing normal lake level. Laketemperatures have only been collected on one occasion, 13 April 1978.The temperature profile indicates that no stratification occurs andlittle temperature change occurred past 8 meters. Although no summertemperatures were taken, using the worse case basis, the area forwithdrawal will oe approximately 4° C.The discharge of 4° C water into Allison Creek may cause the streamtemperatures to be reduced below the powerhouse during the summermonths. The actual impacts on the downstream temperature regime areunknol'm. Pred ict i ng downstream changes in stream temperatures is 1 imiteadue to problems in estimating the degree of mixing in a lateral streamand in evaluating convective and evaporative heat losses under conditionsof local atmospheric stability. Estimates made of the average inflowEIS-8