Study to find solutions to increasing silt at Coralville Lake proceeds

The nonprofit Friends of Coralville Lake is moving forward with its action plan to raise awareness and explore solutions to increasing sedimentation that eventually could close off the lake to recreation.

The group is taking the first step — a preliminary action plan — that’s part of a “bigger picture of what we could start doing to attack this problem,” Jon Kounkel, Friends of Coralville Lake president, told The Gazette. The preliminary plan will look at what solutions are available to address the sedimentation, followed by a feasibility study to see if there’s community interest in pursing it.

The action plan and feasibility study will be funded though the federal American Rescue Plan Act pandemic aid. The Johnson County Board of Supervisors on Thursday unanimously approved the grant agreement.

The project category is to “contribute to the development of the Iowa River Watershed Management Authority, plan and partnerships to address nonpoint sources of pollution,” according to the county.

The board has $25,000 allocated for the current fiscal year in pandemic relief funds. Funds are also budgeted in fiscal 2023 and 2024 — $50,000 each year — for a total of $125,000.

The grant agreement approved Thursday for the Friends of Coralville Lake is only for the $25,000 in fiscal 2022.

“We've had meetings with other local governments and community partners regarding the larger watershed that is Iowa River Watershed and how that looks upstream in Johnson County and beyond, so those conversations are also underway,” the county’s grants coordinator. Donna Brooks. said at last week’s work session of the supervisors.

Friends of Coralville Lake formed in 2016 and focuses on the well-being of the lake. Estimates from the Army Corps of Engineers say there are 20 to 30 years left before the lake silts in and becomes unusable for boating and other types of recreation.

Preliminary action plan

The Friends of Coralville Lake is working with Johnston-based Impact 7G, an environmental consulting firm, on the preliminary action plan. The firm has additional project offices in Coralville, North Liberty and other cities across the country.

There is no quick fix to the problem, Kounkel said, but there are potential solutions — such as buffer strips, silt traps and dredging — which the group is in the early stages of exploring, as well as the impacts of these solutions.

“Right now, we know that there's many, many different options that you can use to attack this problem,” Kounkel said.

Impact 7G’s scope of services will include reviewing documentation and data from the Army Corp about the status of the lake; checking in with agencies to identify potential partnerships; identifying preliminary goals and objectives; and developing an action plan for next steps, according to the professional services agreement in county documents.

The cost of the preliminary action plan is $10,000, according to the agreement. Next steps after the preliminary action plan, according to the agreement, could be a watershed assessment, public outreach plan and economic impact.

“Once we get done with this (preliminary action plan), then I'm expecting that they will have a plan to put in place to say, ‘OK for us to go evaluate dredging, for example, or for us to go to evaluate a silt trap or for us to evaluate taking care of the shoreline erosion problem, here's what it's going to take,’” Kounkel said.

The preliminary action plan won’t have costs estimates of the potential solutions yet, he added.

Feasibility study

The grant funds also will be used toward a feasibility study. Friends of Coralville Lake is working with Cedar Falls-based Amperage Marketing and Fundraising on the study.

The feasibility study will look at community interest, funds needed and ability to execute the plan, Kounkel said.

“If we come up with a plan to attack (the problem with the lake), could we actually execute that plan? So, could we raise the funds to go execute it? Could we could we actually manage it?” Kounkel said about the focus of the feasibility study.

The total feasibility study cost is $25,500, with $12,750 due at the signing of the contract, according to a letter from Amperage in November included in county documents.

The anticipated timeline, Kounkel said, is completing the preliminary action plan in the next three months. The feasibility study would launch after the preliminary action plan is completed and take about six months. Kounkel anticipates the feasibility study to be wrapped up by the end of the year.

“There's a lot of moving parts, and a lot of different pieces of the puzzle where people have different interests, so we need to make sure we take all that into account,” Kounkel said.

Comments: (319) 339-3155; izabela.zaluska@thegazette.com