Residents will notice the lake waters slowly rising again as early as Monday
The generator repair at the hydroelectric dam that prompted an unscheduled drawdown of Lake Lure Dec. 1st is proceeding well.
As such, the Town of Lake Lure has conducted an evaluation of raising the water levels in the lake and its impact on the continuing work at the dam.
Based on this evaluation, the lake level will rise from its current depth of 978.6 to a target depth of 982 or a little more than three feet by Friday, February 24th. Full pond for Lake Lure is 990 feet.
Please remember that weather plays an important factor with raising or lowering our lake level. The Town plans to reevaluate lake levels early next week to determine if additional targets for raising the lake can be made.
With regard to the status of the work, the generator has been removed and the shaft is being sent to a firm in Marion for repairs.
The lower section of the generator has been fashioned such that Town employees will not have to reenter the penstock in order to set the generator back in place. This possibly eliminates the need to keep the lake level quite as low as originally planned.
The penstock is a pipe approximately ten feet in diameter that gets smaller as it reaches the turbines. Its wicket gate controls are being disassembled and all of the old, galvanized metal bolts are being removed.
From the beginning, the Town's intent with this repair project has been to ensure the safety of town staff, protect the hydroelectric equipment at the dam and respond accordingly to the concerns of lakefront businesses and residents.
The necessary draw down, which began Dec. 1st., has taken the lake down about eleven feet, exposing large areas of shoreline, as shown in these photographs.
The lake's drastic reduction in water levels and its resulting naked appearance from the shoreline was a necessary step toward preparations to repair
the small generator that regulates daily lake levels.
It was in late 2016, during regular maintenance, that plant staff noticed a piece of protective coating was missing from the shaft of that generator.
As a result, the generator had to be taken out of commission. A hoist was used to move the large pieces of machinery while work continued outside on the penstock.
The repair, a first of its kind for our dam, could not be made in place or with the lake at its normal level. The generator had to be completely disassembled. The shaft and runner had to be removed and the shaft sent out for repair.
"It has been a major repair and one that was not without many variables and several risks, said Town Manager Ron Nalley.
That's because in order to complete it, plant staff have had to be in the penstock for an extended period of time.
As the intake structure, the penstock controls water flow and delivers it to the hydro turbines. It is a dark, confined and foul-smelling space in which to work.
Individuals working in the penstock, and the resulting void left by the shaft and runner, presents the potential for a catastrophic accident. The risk comes into play because the staff is relying on only one valve to keep the lake from flooding the penstock.
Such an episode would kill anyone in it, damage the power house and the only other generator. In order to eliminate these risks, Town Council, Lake Operations and the Marine Commission made the decision to lower the lake late in 2016.
Prior to the decision, the issue was discussed at length by the Lake Lure Lake Advisory Board, the Lake Lure Marine Commission and the Lake Lure Town Council during the regular meetings held by each board.
Of the two generators at the dam, the smaller generator is the unit used on a daily basis to fine tune lake levels.
The small generator uses approximately three times less water than the larger generator and allows greater flexibility in managing those levels. That is why the repair needed immediate attention.
The Town currently has the lake on a routine drawdown schedule of 'every three years.' This is to maintain the critically important dredging program and to give property owners an opportunity to work on their docks, boathouses and shoreline stabilization projects.
Because such projects require permits and advance planning, the Marine Commission voted to stay on the current schedule and lower the lake again this Dec. 1st 2017 so that residents and property owners can move ahead accordingly with their existing lake-related projects.
The Dam's Role in Lake Lure's Economy
From an economic standpoint, the importance of the generator's proper functioning cannot be overstated.
Thousands of people - residents and visitors - regularly depend on the lake for recreational enjoyment.
If the lake is not maintained at regular levels, that enjoyment is quickly impacted in numerous ways.
Additionally, if the dam is not functioning, it cannot generate and sell hydroelectric power to Duke Energy, as it has for many decades.
The revenues made from the sale of that electricity help to pay for lake operations, some of the lake's annual dredging costs and any costs associated with maintenance of the aging dam.