Archive for category Table Rock Flooding
The rain we’ve received over the past couple days is flowing into the White river and area lakes, so the Army Corps of Engineers has increased the amount of water being released from four lakes.
The Corps is releasing nearly 64-thousand cubic feet per second from Table Rock Dam. It plans to maintain that release for the next couple of days. (more)
LITTLE ROCK, Ark. – The Army Corps of Engineers is advising people in flood plains downstream of Beaver, Table Rock, Bull Shoals and Norfork dams in northern Arkansas and southern Missouri to maintain awareness and monitor lake levels and weather. These lakes are filling and have very little storage capacity to hold additional rainfall, and more rain is forecast in coming days.
People should decide beforehand whether to move belongings to higher ground. Flows downstream can increase quickly, with perhaps no more than an hour or two notice. The timing of the rainfall could make additional releases necessary during the overnight hours.
People in at-risk areas should stay in contact with local emergency officials. If larger than normal releases are required from a dam, warnings will go out through local emergency channels. Local officials may not know you require notification unless you have told them so.
Conditions at the four Upper White River Basin lakes as of Monday afternoon were as follows.
Table Rock Lake near Branson, Mo.: The lake elevation Monday afternoon was 930.3 feet and rising, with more than 90 percent of the flood storage capacity in use. Releases from the spillway and powerhouse were increased to 27,000 cubic feet per second at 4 p.m.
Beaver Lake near Rogers, Ark.: The lake was at elevation 1,130 feet Monday afternoon and rising. About 100 percent of the lake’s flood storage capacity is in use. Releases from the spillway and powerhouse were increased to 30,000 c.f.s. Monday afternoon.
Norfork Lake near Mountain Home, Ark.: The hydropower units are being repaired at the power house, so the Corps is making releases from the dam’s spillway gates instead. The lake was at elevation 578.1 Monday afternoon and rising, with about 90 percent of flood storage capacity in use. The gates are set to release 13,250 c.f.s. Monday afternoon.
Bull Shoals Lake near Mountain Home, Ark.: The lake elevation Monday afternoon was 693.3 feet and rising, with about 94 percent of the lake’s flood storage capacity in use. Due to the increased releases at the two upstream dams and rainfall, releases will be increased to 26,000 c.f.s., which is the equivalent of eight generators at overload capacity. Due to maintenance outage of two generators, some of this release will be passed by opening the spillway gates. All 17 spillway gates will be open to one-half foot.
Do not rely on rumors. If you have questions about Army Corps of Engineers dams, contact your local Corps office. In addition, information is posted on the Internet at www.swl.usace.army.mil. Click “Water Management” to view various lake and river reports as well as links to the National Weather Service river stage and weather forecasts.
*The Baxter County Arkansas Sheriff’s Office says, as of 3:00 PM Tuesday, the U. S. Army Corp of Engineers opened flood gate spillways at the Bull Shoals Dam to 1 ½ feet. This, in addition to discharge from the generators, is putting 46,000 cubic feet per second of water, the equivalent of sixteen generators worth, downstream on the White River. This is double the amount of water normally discharged at maximum power generation utilizing all units. This is an unprecedented discharge of water, and the full effects will not be known for several hours or longer.
This afternoon Sheriff’s deputies went door to door handing out information and warning notice flyer at homes in residential areas along the White River that are expected to be affected by the flooding. Authorities say people residing in affected areas should consider seeking shelter at a safe location now. People choosing to stay at home should pay very close attention to rising water levels. If it becomes necessary to leave, they should do so before exit or escape routes are blocked by flooded roadways, which can be particularly hazardous.
The Sheriff’s Office will be monitoring the situation throughout the evening and into tomorrow.
The Army Corps of Engineers is advising people in flood plains downstream of Beaver, Table Rock, Bull Shoals and Norfork dams in northern Arkansas and southern Missouri to maintain awareness and monitor lake levels and weather.
These lakes remain nearly full from recent rains, and more rain is forecast in coming days.
People should decide beforehand whether to move livestock, equipment and belongings to higher ground. Flows downstream can increase quickly, with perhaps no more than an hour or two notice, and rapidly changing conditions can create even shorter notice. The closer to a dam you are, the faster changes in river stages can occur when releases from a dam are changed.
People in at-risk areas should stay in contact with local emergency officials. If larger than normal releases are required from a dam, warnings will go out through local emergency management channels.
Once a lake is full, it has reduced capacity to lower downstream flood crests. Water still flowing into the lake must be released from the dam
because there is no storage space left. This is sometimes referred to as
“passing the inflow.”
When passing the inflow, a dam does not make conditions downstream any worse than what the natural condition the river would be without the dam in place.
It is just that the dam is unable to do as much to reduce downstream flooding under those conditions.
It is worth noting the lakes are not intended to prevent all flooding. The lakes have limitations that Mother Nature can exceed, and from time to time does. Therefore, downstream property owners should be judicious in how they develop land within the flood plains.
Floods are not as frequent because of the dams, and when they do occur, they are typically not as severe as they were before the dams were built. But there will still be occasions when significant floods occur downstream of these dams.
Below Springfield, MO
View the rest and photos from the flood of 2008 on Hootentown.