|
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
To support recreation on Deep Creek Lake, lake levels should be maintained above elevation 2,458 ft. from early May through mid-October. Drawdown also should be limited each month to permit adjustment of boat docks. To minimize the potential for erosion of sensitive lake shoreline areas, lake levels should not exceed 2461.0 ft. To reduce the potential for entrainment of walleye and perch fry, generation during the early spring should be minimized. To maintain power and energy benefits, the project should continue to operate as a peaking plant, available to generate a minimum of two hours per day on any given week day. Generation is normally scheduled during weekdays to take advantage of relatively higher power values. The figure to the right illustrates the new rule band for operating the project to maintain the desired lake levels to achieve these objectives. Releases of water from the Deep Creek Station can have a pronounced impact on dissolved oxygen (DO) in the Youghiogheny River, particularly during the summer months (click here for figure). Penelec conducted a feasibility study of alternative ways to meet Maryland DO standards and identified a tailrace weir and an oxygen injection system as the most promising alternatives. The tailrace weir was determined to be the most practical and cost-effective solution to correct the DO problem. The tailrace weir, basically a small waterfall which aerates the water after discharge from the power plant, was constructed and ready for operation in December 1994. It is shaped like a "W" to provide the required 430 length needed for aeration within the 40 foot tailrace channel. It is 8.4 feet high and results in a reduction in energy production of about 1% due to headloss. Results show that it is very effective at improving DO in the tailrace at startup. Even with a discharge DO level of less than 0.5 parts per million (ppm), the tailrace DO was never lower than 4.9 ppm. Uptake rates of DO ranged from 0.5 to 4.5 ppm, depending on the discharge DO level. Many variables have affected trout populations numbers in the Youghiogheny River since 1987 when MDNR began sampling. These factors include drought summers (e.g., 1987, 1988, 1991), variable stocking rates, unknown harvest, the catch and release regulations implemented in 1993, and the habitat temperature enhancement measures implemented in 1994. However, standing crop estimates indicate an improving population at Hoyes Run. Measurements at Sang Run are more uncertain due to greater difficulty in sampling in that portion of the river.
Temperature Habitat Enhancement The temperature enhancement protocol was formally implemented in the summer of 1995. The figure to the left shows river temperatures on a typical hot summer day when releases from Deep Creek Station keep the water cool. A report evaluating results for 1995 through 2000 is available in pdf format, Youghiogheny River Temperature Enhancement Protocol for Operating Deep Creek Hydroelectric Station: Model Development and Results for 1995-2000. Implementation of the temperature enhancement protocol between 1995 and 2000 was very successful at maintaining lower temperatures than would otherwise have occurred in the river without the releases. In summary, the total number of days when temperature exceeded 25 °C at Sang Run ranged from two in 1996 to 18 in 1995 (see table below). Temperatures in excess of 25 °C at Sang Run without operation of the Deep Creek Project would have ranged from a minimum of four to 10 days in 1996 to a maximum of 44 to 69 days in 1999. Maximum river temperature rarely exceeded 27 °C at Sang Run and was less than 26 °C on most of the days when it exceeded 25 °C. In contrast, the actual maximum temperature at Swallow Falls was above 27.5 °C 10 times in 1995 and 14 times in 1999. Maximum temperature exceeded 30 °C seven times and six times in those same years. The data from Swallow Falls also suggests that there were very few days when releasing water for temperature enhancement was unnecessary.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Return to the
Maryland DNR Home Page
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||