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Alcoa Power Generating Inc., Yadkin Division
Lake Levels - High Rock 
Historical High Rock Lake Water Levels

(Measured at High Rock Dam)

The following chart indicates what typical lake levels have been each month, based on historical data from 1986-present.

Month Average Feet Below Full1 Range Of Average Highest To Average Lowest Feet Below Full2 Lowest Feet Below Full3 Median Feet Below Full4
January 6.6 3.6 - 10.6 19.4 6.6
February 6.3 3.3 - 9.4 17.9 5.9
March 4.3 2.1 - 7.1 16.5 3.5
April 2.9 1.1 - 5.0 11.4 2.5
May 2.2 1.1 - 3.3 6.4 2.0
June 2.6 1.4 - 3.8 16.4 2.1
July 3.5 2.2 - 4.6 24.0 2.0
August 4.3 2.8 - 5.6 19.8 3.2
September 4.3 2.8 - 5.9 16.4 3.9
October 4.8 2.9 - 7.1 10.9 4.7
November 6.2 4.4 - 8.3 13.4 6.0
December 6.4 3.7 - 9.2 14.2 6.8
1 This is the average of daily water level readings for each month.
2 This is the range of the average of the highest daily water level readings and the lowest daily water level readings for each month.
3 The maximum drawdowns generally occurred in drought years.
4 One half of the daily water level readings are above this figure and one half were below this figure for each month.




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