Forest Supervisor signs Decision for Crane Lake

POTOSI —Mark Twain National Forest plans to rebuild the dam at Crane Lake to eliminate hazards and restore the lake to its original size, allowing recreational access for boaters and anglers.  Forest Supervisor Sherri Schwenke attended the Iron County Commissioners meeting on Tuesday, May 11 to solidify an official Forest Service decision to repair the dam at Crane Lake using a roller-compacted concrete (RCC) method.  She signed the official Decision Notice for the Crane Lake High Hazard Dam Safety and Compliance Project, a choice that was based on extensive investigation and public engagement.

Presiding Commissioner Jim Scaggs, Southern District Associate Commissioner Ben Young, and Western District Associate Commissioner Ronnie Chandler invited Schwenke to join them as she signed the document in a show of support for the decision.  The commissioners, along with other community members and Forest Service employees, shared applause at the signing of the decision.

“I want to thank everyone that has participated with Mark Twain National Forest as we went through this environmental planning process,” said Schwenke.  She added that the robust community feedback and citizens’ willingness to attend meetings and assist in planning efforts truly helped her reach a clear decision.  “This choice will correct all the safety concerns and meet the desire of the community to get back to enjoying their lake,” she added.

At the signing, Commissioner Scaggs shared how happy he was to hear that the lake will one day be restored to its full capacity of 100 acres.  He stated, “It was always a popular place for people to come fish in kayaks and jon boats, and I am looking forward to it being that way again.”

After serious safety issues with the dams were identified, engineering studies at the site began in 2014.  The lake was then drawn down for public safety in 2015.  Since then, multiple public meetings were held, more engineering studies were conducted at the site, and public scoping occurred.  After reviewing all the information, the decision was made to select an alternative that keeps the water surface at 100 acres, can handle waterflow rates associated with a probable maximum flood event, and resist effects of a maximum probable earthquake.

Becky Ewing is the District Ranger for Potosi-Fredericktown Ranger District and has been since 2013.  “I have been working with the Ironton and Fredericktown communities and with user groups since the issues were first identified in 2013, and I am so glad we have this decision so we can get this project started on the ground,” stated Ewing.

Ranger Ewing added that a 65% engineering design for the new dam has already been completed for this selection, and a 100% design is expected by the end of this summer.

A new dam is at least a couple years away; but having this signed decision allows the Forest Service to finalize the design, contract out the work to rebuild the dam, and then begin construction.  The new dam will have a different look.  The earthen embankment will be lowered, the right-side spillway will be filled in, and then both will be capped with RCC.  The RCC section will then act as the new emergency spillway during heavy rainfall events. The left-side spillway walls will be reconstructed and this will serve as the spillway at normal lake levels. 

To prepare for the upcoming work, the lake will be lowered even more in the coming months. This means that only small watercraft will be able to access the lake and might need to be drug across the lake bed to get to the water.  The lowering will allow equipment to access the existing dam’s embankment for geotechnical core drilling and sampling.