OKLAHOMA CITY — Lawton and Comanche both received American Rescue Plan Act grants from the Oklahoma Water Resources Board recently to finance dam repairs.
The Lawton Water Authority received two ARPA grants totaling $11 million from the state agency. Those funds will be coupled with a $925,251 high-hazard dam grant from the Federal Emergency Management Agency and $14,275,345 in local matching funds.
The $26.2 million is earmarked for reconstruction of the flood-damaged spillway in the Lake Ellsworth dam.
Lake Ellsworth’s concrete spillway was damaged after heavy rains in 2015 forced the city to open the floodgates to release runoff water that otherwise would have topped the dam.
City officials knew from the outset that heavy runoff damaged concrete panels in the spillway. However, further analysis revealed other problems, such as empty spaces beneath the spillway that were identified after geotechnical and engineering analyses. The spillway “floated” during the water releases, Lawton Public Works Director Rusty Whisenhunt told Southwest Ledger.
Rehabilitation measures, the Water Board reported, will include adding more robust rock anchors, additional drains beneath the apron, casting a reinforced concrete slab over the existing apron, repairing concrete on the 363-foot-long spillway, retrofitting the spillway retaining walls, adding chute blocks on the spillway stilling basin, and adding riprap along the east side of the spillway.
The Water Authority probably will advertise the project for bids in September, Whisenhunt said.
Lake Ellsworth’s dam is labeled a high-hazard structure because more than 5,200 people downstream would be at risk if the dam failed, the OWRB explained.
According to the state agency, the dam is a combination earth fill and concrete structure 3,900 feet long, 96 feet high, and 30 feet wide at the top. It has 15 gates, each 10 feet high and 20 feet wide.
Lake Ellsworth provides approximately 20% of Lawton’s water, and Lake Waurika about 10%, Whisenhunt said. Lake Lawtonka is the city’s primary source of fresh water.
Ellsworth is northeast of Lawton, between Elgin and Apache, and straddles the Comanche/Caddo county line. It was built by the City of Lawton in 1962 as a source of drinking water and for recreation. The reservoir, an impoundment of East Cache Creek, encompasses 5,100 surface acres and has 53.5 miles of shoreline.
Over the last three years “We have acquired more than $32 million in grants for public utilities projects,” Whisenhunt told the Ledger on July 18.
The Public Works Authority in Comanche, in Stephens County, also received a $1 million ARPA grant from the OWRB. The funds are to be used to seal cracks and reinforce the dam at Comanche Lake, which encompasses about 180 surface acres and was built in 1960; remove trees around the dam; and perform engineering to upgrade a lift station. Some of the funds also will be used to recoat the town’s two water storage tanks.