Caney Coon Creek Watershed Dam 2M Rehab Project Completed
The rehabilitation of Caney Coon Creek Watershed Dam No. 2M was certified complete at a final inspection of the dam on July 10, 2013.
The lake formed by the dam is known locally as the Coalgate Reservoir and it provides over 75 percent of the municipal water supply for the City of Coalgate.The dam has been undergoing rehabilitation since October 2012. It is one of three dams in the Caney Coon Watershed Project, all in Coal County. These dams provide over $357,000 in average annual benefits and provide flood protection for 53 farms and ranches, Highways 3 and 31 and numerous county roads and bridges.
The dam was originally constructed in 1965 as a low hazard dam with a 50-year design life, but was later reclassified to high hazard due to downstream development. The dam was rehabilitated to bring it up to current dam safety criteria to ensure that it remains safe and continues to provide multiple benefits for another 100 years. Safety concerns grew over the years when heavy rainfall in the area almost caused water to overtop the dam on two occasions. Failure of the dam could have put lives at risk downstream and resulted in the loss of the water supply for the City.
Rehabilitation of the dam included the installation of a new principal concrete spillway pipe and inlet tower and a roller compacted concrete (RCC) overtopping auxiliary spillway. This is only the second RCC overtopping spillway installed in an Oklahoma rehabilitation project. Over 240,000 pounds of steel were used in constructing the RCC spillway.
The project was designed by the URS Corporation in Denver and the contractor was Wynn Construction Company headquartered in Oklahoma City. NRCS provided inspectors during the rehabilitation construction. The project cost $4.7 million with 65 percent of the funds coming from the NRCS Watershed Rehabilitation Program and 35 percent provided by the local project sponsors through state appropriations to the Oklahoma Conservation Commission Watershed Rehabilitation Program.
“This rehabilitation project had some unique challenges,” said Joe Freeland, NRCS Project Engineer. “Rehabilitation of the dam required the water level to be lowered which meant the City had to monitor the water supply and have an alternate water source available during construction. Fortunately, the alternate water supply was not needed and good rains replenished the lake level soon after the project was completed. The cost was considerably higher than many rehabilitation projects due to the high construction cost of the RCC overtopping spillway, which was the only feasible alternative for an auxiliary spillway.”
When the Caney Coon Creek Watershed Project was developed in 1958 the population of Coalgate was 2,300 and growing. Thirteen water wells had been drilled between 1910 and 1953, but only five wells were still producing and they were only providing 160,000 gallons per day. Drilling additional wells was not an option for the City. The City of Coalgate partnered with the Coal County Conservation District, Oklahoma Conservation Commission and Natural Resources Conservation Service (NRCS) to construct the dam in 1965 as a multi-purpose dam to provide flood control, a water supply and recreational areas.
NRCS provided technical and financial assistance in constructing the dam through the Watershed Protection and Flood Prevention Program and local sponsors obtained needed easements and land rights. The City paid for adding an additional 3,000 acre-feet of water storage beyond what was needed for flood control to serve as a water supply. Today the lake provides 75 percent of the municipal water for the city with water wells providing the other 25 percent.
“The completion of the rehabilitation project has given us a real peace of mind in that we will not have to worry about a source of municipal water or about the safety of a 48-year-old dam,” said Roger Cosper, Coalgate City Manager. “Extending the life of the dam for another 100 years, increasing the surface acres of the lake from 350 acres to 400 acres and bringing it up to current dam safety criteria will help us meet current and future needs of our community.”
Others involved agree that water quantity is an important consideration. “As time goes on, water availability for all urban areas will become increasingly important,” said Deward Strong, Coal County Conservation District Chairman. “Here in Coal County, we are not blessed with an underground water aquifer. Like many areas across this great nation, stored water is our only alternative as a secure water source. Rehabilitating Caney-Coon Watershed Creek Dam No. 2 to increase the storage capacity just shows how several entities can come together through planning and funding to create a valuable asset for Coal County and its people.”
The Oklahoma Conservation Commission (OCC) was an integral partner on the project and Mike Thralls, OCC’s executive director, is proud of the project’s success. “The construction of the dam in 1965 is a good example of how local people, conservation districts, OCC and NRCS have partnered to solve multiple resource issues across the state utilizing the NRCS Watershed Program,” he said. The dam not only solved some serious flooding and erosion problems, but it met a critical local need for a water supply. Rehabilitation of the dam ensures that the dam will continue to provide these benefits for another 100 years.”