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[Shelbyville Times-Gazette]
Shelbyville, Tennessee ~ Saturday, October 11, 2008
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Lake level is up, but still far below normal

Monday, March 10, 2008

TVA's gauge that measures the level of Normandy Reservoir is back in operation, but the numbers still show that the amount of water in the lake is far below normal.

According to figures reported by the Tennessee Valley Authority's web site this morning at 6 a.m., Normandy was at an elevation of 858.66 feet above sea level, with water flowing out of the lake at a rate of 42 cubic feet per second (cfs).

Measurements taken at this time last month showed the lake at 852.98 feet. TVA estimates put the inflow at 190 cfs, no doubt caused by the amount of recent rain and snow fall.

But even though the area has seen it's share of rain events, the level of the lake is still below where officials would like it to be.

According to Normandy's operating guide, the lake should currently be around a level of 866 feet at this time of year.

Doug Murphy, executive director of the Shelbyville-based Duck River Agency, said this morning that the amount of rainfall has not been nearly what is needed to meet the reservoir's operating guidelines.

"We're still in a drought," Murphy said Monday, adding that the recent lowering of the outflow of the dam has helped conserve the water in Normandy.

Reducing the amount of water required at gauge 221.4, which is the location of Shelbyville's water intake, has been a major contribution to the level of the lake rising.

But one of the biggest contributing factors to getting more runoff to the lake has been last week's snowfall, which soaked the ground with moisture.

"Now that the ground is saturated, we're going to get a lot better runoff to the lake, Murphy said. "That snow was a real blessing."

But Murphy cautioned that rainfall is still below normal -- almost 50 percent, according to his estimates. Also, area wetlands and ponds need to be filled first before the lakes.

According to data supplied by TVA, only a total of 6.5 inches of rain have fallen at Normandy Lake since the first of the year: A total of 1.84 inches in January, 3.30 inches in February and 1.36 in the first nine days of March.

Murphy said last month that between 10 to 15 more inches of precipitation over the next three months would be needed to make "a significant impact" to the level of the lake.

It would take an average of five inches a month to get the level up to the lake's winter pool as stated in Tennessee Valley Authority's operating guidelines for the reservoir, Murphy said in February.

According to TVA, the Tennessee River watershed has one of the highest annual rainfall totals of any watershed in the United States, with an average of 51 inches of rain a year.

The monthly average rainfall in the Tennessee Valley ranges from 3.0 to 5.5 inches, TVA says, with March, July, and December typically being the wettest months, and September through November typically the driest. Of course, in any year, the wettest and driest months may be different.

The monthly average runoff varies from a high of almost four inches in March to a low of less than one inch in August, September, and October, TVA says.


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The only thing I can say is how can a lake level rise if there is water being drained from it daily? and there's no rain to fill it back up? I think it's poor water management. We will definitely have big problems this summer if we don't get enough rain again this year.

-- Posted by onlywords on Tue, Mar 11, 2008, at 2:09 PM

The water level is up due to all of the tears from the people who opposed SSA.

-- Posted by seedsower on Mon, Mar 10, 2008, at 10:24 PM


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