The Pearl River Valley Water Supply District issued the following press release.
Barnett Reservoir increases discharge
Barnett Reservoir officials increased discharge at the dam Saturday morning to 40,000 cubic feet per second to slow down a rise on the lake in advance of a Wednesday crest on the Pearl River.
In a morning conference call with the National Weather Service, the Lower Mississippi River Forecast Center in Slidell, the U.S. Army Corps of Engineers and the City of Jackson, the Pearl River Valley Water Supply District said the move was necessary to stop a rise in the 33,000 acre lake northeast of Jackson.
All participants agreed that the discharge level should be maintained for 24 hours, with another conference call scheduled for 9:30 a.m. on Sunday.
The National Weather Service is forecasting a crest of 34 feet in Jackson on Monday night, which will cause some street flooding. The forecast is based on inflows, past rainfall and predictions for the next 48 hours. PRVWSD adjusted the discharge from 30,000 to 35,000 feet Friday night and then to 40,000 at 5 a.m., and at 10 a.m. it appeared the lake was cresting at 298 feet (above sea level).
Heavy rainfalls throughout the upper Pearl River Basin and on Barnett Reservoir caused an immediate rise of the river and the lake. The peak inflow of water into the reservoir is forecast at 43,900 cubic feet per second on Wednesday. By increasing discharge, the plan is to lower the lake before the peak inflow to create storage capacity
and reduce the ultimate river crests at downriver locations.
The public can track river forecasts online at the websites:
Ross Barnett Reservoir
Jackson
7 comments:
water, water everywhere, and not a drop to drink.
what is this bird hanging around by neck...
it's an albatross
I believe I read that the level of the reservoir is not lowered for the winter and spring any longer thus there is not much extra they can hold back. I think that will lead to higher flood levels downstream now.
Pearl River Valley Water Supply District
EFFECTIVE IMMEDIATELY
April 18, 2013
Barnett Reservoir Board of Directors adopts new lake level plan
Pearl River Valley Water Supply District’s Board of Directors on Thursday approved a
plan to change the lake level operation of Barnett Reservoir near Jackson.
District General Manager John Sigman said the proposal directs an increase of one foot
in winter pool elevation, from 296 feet above sea level to 297 feet, from December 1
through April 10 each year.
The summer or recreational pool will remain 297.5 on the 33,000-acre lake for the rest
of the year.
“Under the previous plan, this month we began raising the lake level April 10 from
winter pool of 296 with a goal of reaching summer pool,” Sigman said. “Historically, there
have been years when we were unable to achieve summer pool. A winter pool of 297 gives
us a greater chance of reaching our target summer pool.
“We are confident that we can do this without increasing flood risk downstream, and maintaining our ability to mitigate the peak of flood events just as we have in the past.Technological advances in areas like river gauging and computer modeling give us quicker,better data to help manage high-water events. For example, we had four river gauges to use in the 1979 and ’83 floods. There are now eight gauges and they provide updatedinformation every 15 minutes.”
Sigman said Barnett Reservoir’s final design was not a flood control reservoir. Original
concept planning hoped to achieve flood control, but it was soon realized that would not be
possible. The reservoir was instead designed to provide a water supply for the City of
Jackson, and provide the area a source of recreation. He said the change in lake level would
enhance both roles, while not reducing the dam’s ability to reduce flood impact.
“Even back in 1979 and 1983, we were able, with the information resources available
then, to take between 25 and 30 percent off the peak of those catastrophic flood events,”
Sigman said. “We underwent a long process with this plan to ensure we could maintain that
ability. We are confident that we can provide the same flood reduction whether we are at
296 or 297 feet above sea level.”
Sigman said the new plan underwent thorough hydrological research by Blake Mendrop
at Mendrop Engineering in Ridgeland and subsequent examination by many groups,
including the U.S. Army Corps of Engineers, the U.S. Geological Survey, and the National
Oceanic and Atmospheric Administration’s National Weather Service and its Lower
Mississippi River Forecast Center.
“We had several of the brightest minds in this field look at this plan and they agreed the
research was sound; they could not poke holes in it,” Sigman said.
Reservoir officials initiated conversation with several counties and municipalities
downstream and met with officials to give them an opportunity to hear the plan.
“We heard their concerns, which range from river bank sloughing, local flash-flooding
and even low water flow in the summer and fall,” Sigman said. “While the reservoir has
little or no impact on some of those, I do feel very strongly that we can better address those
that we can impact, such as the sloughing of banks, by having more water.”
Thursday’s action adopts the engineering report and initiates the new operational rule
— April 10 to Oct 15, a level of 297.5; Oct 15 to April 10, a level of 297, with a half foot
bandwidth on either side of the operational target.
The Ross Barnett Reservoir was designed and built to provide a water source for the City of Jackson.
Accordingly, please join us in prayer this Sunday morning, thankful to God that this project, unlike the Evers Airport, was never owned by, run by, managed by or directed by the City of Jackson.
(Cue Rod Serling) Imagine, if you will, a Board of Directors, appointed by the mayor of Jackson, approved by the Jackson City Council, having anything whatever to do with the operation of our reservoir and the public lands surrounding it.
There are many of us still around that remember the severity of Pearl River flooding BEFORE the Ross Barnett Reservoir was constructed. While 7:32 is correct that RBR was built to supply Jackson with a drinking water source, there were hopes early on that it could also be used for flood control. Those hopes were put to rest long before completion of RBR, BUT, if RBR was not there and the planning of pool levels and amounts of water outflow was not done so professionally, one can only imagine what would have happened in 1979 and even now with respect to flooding. People want to compare RBR to Sardis, Grenada, Enid and Arkabutla reservoirs, all of which were designed and built to be flood control reservoirs. Sorry, but RBR is not for flood control, but many homes and businesses have been spared flooding due to the engineers working hard to best control when and how much water to release. Just imagine if the dam was not there or the spillway gates stayed wide open all the time. Be thankful for what you have.
P.S. I was a victim of the Flood of 1979.
Not drawing the lake down to winter pool is plain ignorant. Remember how bad the water got back in 2014 and I'm afraid we're going to see it this year as well.
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