Although an analysis of a 2018 assessment ranks Truman Dam in Warsaw as a moderate to significant risk among more than 700 dams operated by the U.S. Army Corps of Engineers, federal officials say there is no immediate threat or imminent danger.

Although an analysis of a 2018 assessment ranks Truman Dam in Warsaw as a moderate to significant risk among more than 700 dams operated by the U.S. Army Corps of Engineers, federal officials say there is no immediate threat or imminent danger.

What that means, according to the Corps, is that flooding during an extreme rain event could  overtop the dam or potentially cause a release that would create a safety hazard downstream.

Truman Dam is currently operating as designed and is NOT under a current threat for breach due to a structural problem with the dam., the Corps said in a statement on Mar. 7..

Based upon the most recent risk assessment in 2018, the Corps considers the dam to be a risk dam due to the large population located below the dam and due to the potential for overtopping during an extreme flood. USACE manages this risk by conducting routine monitoring and evaluation and has implemented interim risk-reduction measures and/or long-term measures to reduce this risk.

Downstream residents, including those on Lake of the Ozarks are encouraged to attend a community open house Wed., Mar. 13, 2019, from 5 p.m. to 7 p.m. at the Harry S. Truman Dam Visitors Center, located at Truman Lake. The open house is being sponsored by the Kansas City District office of the US Army Corps of Engineers.

The open house will consist of open dialogue regarding risk awareness between the community and Corps of Engineers personnel. The open house will focus on promoting emergency preparedness and provide the public  information on evacuation readiness, and communicate dam risk to the population-at-risk located downstream. Truman staff and experts on dam safety and the engineering assessment will be on hand to answer questions regarding the risk evaluation; emergency preparedness; powerhouse repairs; and other ongoing projects.

The Corps has partnered with Benton County Emergency Management to implement the RAVE Alert emergency notification system.

Benton County Emergency Management Director Mark Richerson said the county and Corps will be discussing the notification system and how it works for those who are downstream of Truman Dam. That area includes Lake of the Ozarks, he said.

“This is about safety,” Richardson said. “We will be able to notify the public of conditions. I would recommend this for anyone on the downstream side. It’s a mass notification system.”

Richardson said the open house will be followed by a training exercise for all the agencies involved. The exercise will be similar to what Ameren Missouri periodically conducts at Bagnell Dam at Lake of the Ozarks.

Truman Reservoir is the largest flood control reservoir in Missouri, with a storage capacity of more than 5 million acre-feet (an acre-foot = 325,000 gal.). At normal pool (706 ft. above mean sea level) the reservoir has a surface area of about 55,600 acres – this surface area can grow to over 200,000 acres at the top of the flood control pool. During periods of flooding, Truman Reservoir, operating in conjunction with other reservoirs, helps protect the lower Osage, Missouri and Mississippi River floodplains.

Harry S. Truman Dam was designed and built by the U.S. Army Corps of Engineers, Kansas City District and completed in 1978. USACE operates Harry S. Truman Dam for flood damage reduction, hydroelectric power generation, recreation, water quality, water supply, and fish and wildlife.

The main components of the project are an earthen embankment section,
which serves as the main water barrier composed of compacted earth,
concrete gated spillway structure that allows controlled water flow out of the dam, and a hydroelectric powerhouse. The earthen dam is 5,964 feet long, 123.9 feet high, and top of the dam is 35 feet wide. The elevation of the top of the embankment is 756.4 feet. The foundation is made up of earthen materials. The concrete spillway is located at the right end of the embankment section and is 190 feet wide with an elevation of 692.7 feet . The spillway can pass up to 2,124,20 gallons per second (284,000 cubic feet per second) or approximately the volume of three and a half Olympic-sized swimming pool each second.

During normal operations, the lake is kept at a relatively consistent level (referred to as conservation pool). Should heavy rains occur in the spring or at any other time, surface water runoff is stored in the lake until the swollen streams and rivers below the dam recede and can handle the release of stored water without damage to lives, property or the environment. Sometimes water must be released to protect the dam’s integrity even though streams and rivers may have already reached or exceeded their capacity. Truman operators and those at Bagnell Dam work closely during periods of significant rainfall or flooding to minimize releases that pose a potential threat for downstream flooding.

According to the Corps, dams reduce but do not eliminate the risk of economic and environmental damages and loss of life from flood events. When a flood exceeds the reservoir's storage capacity, large amounts of water may have to be released that could cause damaging flooding downstream. A fully-functioning dam could be overtopped when a rare, large flood occurs, or a dam could breach because of a deficiency, both of which pose risk of property damage and life loss. This means there will always be flood risk that has to be managed. To manage these risks, the Corps  has a routine program that inspects and monitors its dams regularly. The agency implements short- and long-term actions, on a prioritized basis, when unacceptable risks are found at any of its dams.

Closer to home, Ameren Missouri recently completed a  $53 million reliability upgrade to the historic Bagnell Dam. The project included installation of a series of new anchors and concrete on the downstream side of the dam, which improves overall safety, efficiency and reliability of the 85-year-old structure.

Initial work began March 2017 and included the removal of timeworn concrete from the surface of the dam. Crews then installed 67 post-tensioned anchors, strengthening the connection to bedrock. More than 66 million pounds of new concrete was poured to further weigh down the dam. This is the first major structural update in more than 30 years and builds on Ameren's expertise in enhancing dam safety.