Burlington’s Echo Lake is covered with algae during July 2019. Officials believe blooms such as this are linked to phosphorus that has infiltrated the lake. City officials are considering a study that analyze the sediment of the lake and possibly lead to dredging. (Photo by Ed Nadolski)

Results would help council determine future of dam, lake

By Jason Arndt

Staff Writer

Community members, at times, have expressed concerns related to ongoing issues on Echo Lake ranging from degradation of recreational use as well as algae blooms.

The issues, according to city officials, have resulted in a need to further explore sedimentation at Echo Lake through a proposed hydrosurvey. The study is under Common Council consideration and set for possible approval at a meeting April 7.

Peter Riggs, Director of Public Works, said in a March 23 Committee of the Whole meeting area residents brought forward concerns about Echo Lake.

“The sedimentation of Echo Lake has been an issue that comes up from time to time when talking with members of the community. We have all seen the degradation of that body of water from a recreational use standpoint and also recent algae blooms,” he said.

Riggs, in a council document, said he suspects phosphorous may have contributed to deteriorating conditions on Echo Lake.

“It is suspected that sedimentation in Echo Lake contains much legacy phosphorous which is harmful to the watershed and contributes to algae blooms,” he wrote. “Understanding of the sedimentation and the flow path of the White River to the Echo Lake Dam are also important for the analysis of compliance alternatives for the Echo Lake Dam Spillway.”

The hydrosurvey and sediment sampling, if approved by the Common Council, would come at a cost not-to-exceed $18,900 from Ayres and Associates, Inc. and includes a pre-dredging investigation.

The pre-dredging investigation, Riggs added, could help city officials rule out or determine whether a dredging project would be needed.

“We have considered, at least hypothesized, about a dredging project for that body of water,” he said.

Dual objectives

The Common Council previously authorized an adaptive management plan for phosphorous compliance as well as an Echo Lake dam feasibility study. The hydrosurvey would help the city accomplish both objectives at the same time.

The adaptive management plan approved by the Common Council on March 2 includes recommendations on how to address phosphorous in Echo Lake as part of the first two permit terms.

Additionally, on Feb. 16, the Common Council endorsed an Echo Lake Dam Spillway Feasibility Study, which will explore compliance alternatives for the dam, including total removal.

“We essentially accomplish two goals here – the phosphorous management with our AMP and also information that greatly aides with our analysis of that Echo Lake dam feasibility study,” Riggs said.

As for potential dredging, the hydrosurvey and sediment sampling will help the city make a more informed decision on related expenses and feasibility for the project.

“The first step in that process would be to complete a hydrosurvey and take sediment samples of the lake to determine costs and feasibility of a potential dredging project,” Riggs wrote in a council document.

To read the complete in-depth story of the proposed lake study see the April 1 edition of the Burlington Standard Press.