KIMBALL -- Construction crews spent just over one month on a rehabilitation project at the Oliver Reservoir that has recently been completed. 

Construction crews from Paul Reed Construction & Supply, Inc. successfully completed the Stilling Basin Rehabilitation Project at the Oliver Reservoir Recreation Area on Oct. 10. 

The South Platte Natural Resources District had been planning this project for several years, General Manager Galen Wittrock said. During an annual inspection by the state about 5 – 6 years ago, the inspector noted signs of aging to the concrete of the stilling basin. 

“The stilling basin is a concrete structure that is designed to – when the water flows out from the primary spillway underneath the dam – slows that water down so it doesn’t cause erosion," Wittrock said.

He pointed out that the stilling basin is not a component to cause concern of the dam breaking. 

“People sometimes think that the stilling basin is getting old, and the dam is going to break, but it’s not because the location [of the stilling basin] is on the downhill side,” he said. “The integrity of the dam is still good, and we always watch that.” 

Wittrock said the original stilling basin was built in 1911, so he imagines this new one will last at least another 100 years as well. 

“This project is beneficial in that if we ever have a huge flood, it will alleviate a lot of issues downstream,” he said. “It cost $300,000, so it wasn’t a cheap project, but what we needed to do is up-to-speed with state requirements, and now we can look forward to doing additional recreational improvements for Oliver Reservoir like picnic tables and possibly more camping sites.” 

The entirety of the project took place from Sept. 2 – Oct. 10, which Wittrock said was a very efficient timeline. 

“They did a great job at quickly removing the old structure and getting a new one up,” he said. 

The main stages of the project include:

Sept. 2-5: Removal of the existing concrete outlet structure 

Sept 8–12: Installation of forms and pouring of the mud mat for the basin base 

Sept 15–19: Installation of forms and rebar, pouring of the basin floor, and initial work on basin wall forms 

Sept 22–26: Wall pours and form stripping 

Sept 29–Oct 3: Grading and placement of riprap downstream 

Oct 6–10: Backfilling, railing installation around the impact basin, and perimeter drain installation 

Oct 10: Final walkthrough with the contractor, Paul Reed Construction 

To see the full photo gallery of the project, visit their website SPNRD.org, then scroll down to “Home of Oliver Reservoir” and click the box that says: “Stilling Basin Replacement Project Photos.”