Question: "Is it true that Lexington will be without water for 53 days, if we experience the 1930 drought of record?"

Clarification: The 53-day number came from one of the deficit analyses (performed as part of the KWRI study) for the 1930 drought under 1994 demand conditions. However, this analysis ignored conservation, valves, and the current KAWC permit. This analysis was performed to provide a basis for comparison with a previous Harza study and not for projecting existing or future conditions. The projected deficit for the drought of record (using 1994 demands) and based on existing facilities in the Kentucky River at the time of the study was actually eight days. However, this number still ignores the influence of the valves and assumes the 7Q10 water quality regulations would be enforced throughout the drought. In fact, these regulations can be temporarily relaxed by the governor. This analysis also ignores the use of any demand management.

Question: "Is it true that with existing demands, the Lexington community faces a water supply deficit of over 20 million gallons per day during a major drought, amounting to a total deficit of 9.7 billion gallons?"

Clarification: As previously explained, the 9.7 billion-gallons deficit is for a conservative baseline condition (and those assumption are not valid for the existing river system) and based on 2020 demands.

Question: "Is it true that the total deficit projected by the University of Kentucky Water Resources Research Institute Study (e.g., 9.7 billion gallons) can be reduced, but not eliminated, with valves on the Kentucky River?

Clarification: "The 9.7 billion gallon deficit is for a conservative baseline condition (and those assumptions are not valid for the existing river system) and based on 2020 demands. Using the valves to remove (mine) up to four feet of water from the pool depth reduces the deficit up to 70 percent or by about seven billion gallons. By mining eight feet of water from the pools, the deficit can be reduced up to 86 percent or by 8.3 billion gallons. Currently, East Kentucky Power Company’s raw water intake prevents pool 10 from being mined below two feet. To correct this problem, the intake would have to be lowered at an estimated cost of about two million dollars. Beattyville’s raw water intake also currently prevents pool 14 from being mined. This intake can be lowered for 500,000 dollars. With significant demand management (e.g., limiting Lexington withdrawal to 31 MGD) and by mining eight feet from some pools, there should be enough water from the Kentucky River to provide Lexington even in the event of the 1930 drought of record."

Question: "Didn’t the KWRI determined that the crest gates on the Kentucky River would only partially eliminate the water supply deficit."

Clarification: The KWRI determined that using the valves (with mining up to four feet from the pools), along with four-feet high crest gates, would completely eliminate all of the deficits—up to and including the 1930 drought of record—for the entire river through the year 2020. After presenting its conclusions to the Kentucky River Authority, concern was raised about possible public reaction to crest gates in pools 11 and 12. As a result, the KRA decided to postpone consideration of crest gates on these dams. As a result, the PSC concluded that the Kentucky River would not support a complete solution to the projected water supply deficit. Their conclusion was the basis for their directive to Kentucky American Water Company to pursue other possible solutions for water supply. Unfortunately, that conclusion did not consider the possibility of mining some of the pools beyond four feet, which could have more than offset the loss of potential storage in eliminating crest gates from consideration for dams 11 and 12."

Question: "Is it true that the dams cannot adequately support crest gates due to stability issues related to the age of the dams, and that some of the dams are built on rock-filled timber cribbing?"

Clarification: "Currently, it is uncertain what additional work may be needed to strengthen the existing dams so that they can support crest gates. Harza engineers have performed a preliminary stability analysis on each of the structures. The proposed crest gates would not be placed on dams that have rock-filled timber cribbing. Regardless of whether crest gates or built or not, the dams will have to be maintained."

Question: "Isn’t it true that the existing dams are in bad shape and that millions of dollars will have to be spent repairing them before that crest gates can be added. If that is the case, how can crest gates be the most cost effective solution?

Answer: "When determining the cost of the crest-gates, Harza did not factor in any additional costs that would be required to repair the existing dams. However, it must be recognized that the existing dam system will continue to provide central Kentucky with the majority of its water supply. As a result, such repairs will have to be made regardless of what alternative is selected to deal with the potential three million gallon deficit. As a result, it is inappropriate to attribute such repair costs with the crest-gate proposal since the proposal costs are limited to only related to providing the additional three million gallons of storage.

Question: "It has been reported that there are many potential problems and unknown maintenance costs associated with the crest gate solution. Is there a more-cost effective solution that uses the Kentucky River?"

Answer: "The most cost-effective solution to the projected water supply deficit would be to simply raise the existing dams four feet in height. Harza has estimated that each dam could be raised for less than 1 million dollars. This solution has an added benefit of minimal reliability issues or significant maintenance issues. In addition, such a solution could be implemented in phases thus potentially saving additional money.

Question: "Why isn’t this solution being pursued as opposed to the use of crest gates?

Answer: "Crest gates have been proposed over permanent dams out of a concern for possible increases in river stage during times of floods. During floods, the crest gates would be lowered so that the dams would be at their existing levels whereas for permanent dams, the levels would continue to be four feet higher. However, a lot of the concern about increased flooding is based on a lack of understanding of the hydraulic impact. It should be recognized that pools 9 and 10 actually have two dams with the locks located in-between. In each case, the auxillary dam, (the one not in the direct channel) is already six feet higher than the main channel dam. So for these two sites, raising of the main channel dams by four feet still leave these dams two feet lower than the existing auxillary dams. As a result, these dams would only partially restrict the flow over across the river cross-section. In addition, raising the dams four feet does not mean that all flood stages will increase uniformly by four feet. The amount of increase decreases as the flood depth increases. For example, Harza has estimated that in the event of a flood with a depth of 20 feet above the tops of the dams, the incremental increase in depth would only be one foot. This would be even smaller for larger floods."

Copyright ©1999 Kentucky Water Research Institute,
University of Kentucky