Table Rock Lake

Table Rock Lake
File:Aerial photo of Table Rock Dam, lake, and White River, October 2009.jpg Aerial photo of Table Rock Dam, in Branson, Missouri, which impounds the White River and forms the lake.
Location	Missouri / Arkansas
Coordinates
Type	reservoir
Primary inflows	White River, James River, Kings River
Primary outflows	White River
Basin countries	United States
Surface area	43,100 acres (174 km2)
Max. depth	220 feet (67 m)
Water volume	3,462,000 acre⋅ft (4.270 km3)
Shore length1	Flood Pool- 857 miles (1,379 km) Normal Pool- 745 miles (1,199 km)
Surface elevation	915 ft (279 m)
Settlements	Branson, Missouri
1 Shore length is not a well-defined measure.

Table Rock Lake is an artificial lake or reservoir in The Ozarks of southwestern Missouri and northwestern Arkansas. The lake is impounded by Table Rock Dam (location ) constructed in 1954-1958 on the White River by the U.S. Army Corps of Engineers.

It is one of the popular draws for the nearby town of Branson, Missouri. There are several commercial marinas along the lake, and Table Rock State Park is located on the east side, both north and south of Table Rock Dam. Downstream from the dam, the Missouri Department of Conservation operates a fish hatchery, which is used to stock trout in Lake Taneycomo. The cold water discharged from the dam creates a trout fishing environment in Lake Taneycomo.

Lake air temperature

The lake area temperature varies according to season:

• Spring: 56 to 77 °F (25 °C)
• Summer: 85 to 90 °F (32 °C)
• Fall: 71 to 82 °F (28 °C)
• Winter: 42 to 47 °F (8 °C)

Lake data

Dam and Outlet Measurements

• Length of dam- 6,423 feet (1,958 m)
• Length of concrete section- 1,602 feet (488 m)
• Maximum height of dam above stream bed- 252 feet (77 m)
• Concrete in dam- 1,230,000 cubic yards (940,000 m³)
• Earth in embankment- 3,320,000 cubic yards (2,540,000 m³)
• Length of spillway- 531 gross feet
• Spillway crest gates size- 45x37 feet
• Outlet conduits size- 4x9 feet

Dam elevations above mean sea level

• Top of dam- 947 feet (289 m)
• Spillway crest- 896 feet (273 m)

Lake elevations above mean sea level

• Top of flood control pool- 931 feet (284 m)
• Top of normal pool- 915 feet (279 m)

Surface area of lake

• Flood control pool- 52,300 acres (212 km²)
• Normal pool- 43,100 acres (174 km²)

File:Table Rock Dam during April 2008 White River Flood.jpg

Table Rock Dam during the April 2008 flood with all flood gates open

Maximum storage capacity

• Flood control pool- 760,000 acre-feet (940,000,000 m³)

Shoreline length

• Flood control pool- 857 miles (1,379 km)
• Normal Pool- 745 miles (1,199 km)

Other

• Power drawdown and dead- 2,702,000
• Lake total- 3,462,000

Power generating data

• Number of generating units- 4
• Rated capacity for each unit- 50,000 kilowatts
• Station installed capacity- 200,000 kilowatts

Flood control

The original purpose of the reservoir was for flood control on the White River. The dam had been authorized a month earlier under the Flood Control Act of September 3, 1943. The reservoir has a fluctuation of 16 feet (4.9 m). When the reservoir is above the maximum flood pool, excess water goes over the auxiliary overflow spillway at the north end of the dam.

The worst-case scenario of a catastrophic floodwater discharge from Table Rock Lake using the auxiliary floodgates would roughly resemble this:

At elevation 931 Table Rock Lake is at full flood capacity. The ten Tainter gates are opened to accommodate additional lake inflow from the White River Basin including the James River and Beaver Lake discharge.

At elevation 937 Table Rock Lake is 6 feet above flood capacity. The ten Tainter gates are opened wider in an effort to stabilize reservoir rise. Outflow from the Lake under these circumstances will be nearing 200-300 thousand cubic feet per second (CFS).

Between elevations 937 and 942 the dam’s ten Tainter gates will be fully raised letting loose 450 thousand CFS into the Taneycomo Lake. This scenario would effectively submerge and destroy the powerhouse, power transmission grid, hatchery, and wreak serious destruction down stream. An illustration of how Table Rock’s ten spillways might appear under these circumstances mimics this: the floodgates will extend up and out from the structure, like eyebrows, shadowing the concrete spillways!

At elevation 942 if reservoir levels are not yet stabilized, the auxiliary floodgates are brought on line, in concert with Table Rock’s fully opened floodgates. This catastrophic protocol releases 1 million CFS of lake waters into Taneycomo and deals dreadful destruction to Branson, Hollister, Point Lookout and possibly the Taneycomo Dam.

Beyond an elevation 942 there is a danger of water overtopping the concrete dam and breaching the earthen structure, which imminently leads to cataclysmic structural failure and the uncontrolled release of the Table Rock Lake impoundment—nearly 3 million CFS of water.

SOURCE:

Further reading

• "Wake Up to Table Rock Lake", pamphlet available at the Table Rock Dam Visitors' Center