Posted on December 11, 2018
The Hickory Grove Park campground, southwest of Colo, will still be open in 2019, but activities at Hickory Grove Lake will be in “pause mode” next year.
Story County Conservation is ready for Hickory Grove Lake to undergo a huge restoration project — estimated by engineers at $3.4 million — which will address issues that have put the lake on the Iowa Department of Natural Resource’s “impaired waters” list in recent years.
Mike Cox, director of Story County Conservation, said his department will have project bids and make a recommendation to the Board of Supervisors on Dec. 11. The DNR will also make a presentation to the state’s Natural Resources Commission later that week on the project, which is anticipated to start this coming spring, or sooner if weather allows. The lake restoration is a joint project between Story County and the DNR.
Cox, who is an Iowa State University graduate with a degree in fisheries and wildlife biology and who started his position with Story County in 2011, explained what has happened to put Hickory Grove Lake on the “impaired waters” list.
“Water bodies in the state are classified for different types of uses,” Cox said. “Hickory Grove Lake is classified for ‘recreation.’”
When the DNR listed the lake as “impaired,” it did so, Cox said, because the lake was not meeting the standards needed to support its “recreation” classification.
?(The impaired listing) doesn’t mean it isn’t safe … but it does mean that at certain times, the water doesn’t meet the quality for recreational use,” Cox said, noting that swimming is one of the biggest recreational uses of the lake.
Cox said in 2008, the Story County Conservation Department began an assessment of the watershed. That assessment showed several problems at the lake, including high bacteria levels and soil sedimentation in the lake.
“We had soil erosion…soil coming out of the watershed and depositing in the lake.” He explained that the soil coming into the lake not only “plugs” it, but it also has a negative effect on water quality.
The East Basin
Standing near the east basin of Hickory Grove Lake, which is on the east side of 680th Avenue, Cox pointed to some of the work that his own department has been doing over the past several years to address the problems. The work has included stream bank improvements to control erosion on the east basin. “This stream (going through the east basin) feeds 75 percent of the lake’s water,” Cox said.
Optimally, the east basin should have its deepest point at 13 feet, but looking at it last week, Cox guessed that the deepest point in the basin might be 4 feet, due to the amount of sediment that has collected there.
He used a kitchen appliance analogy to help explain what is happening. “The east basin serves as a catchment basin for the sediment coming in on the stream. Think of a kitchen strainer in your kitchen sink. If the strainer — basin — is full, we need to empty the strainer.”
Because the east basin can no longer hold it, more sediment has made its way into the main part of the lake that lies west of 680th Street.
Improving what is flowing into the lake has meant working with landowners in Hickory Grove Lake’s 4,000-acre watershed. “We’ve been successful at eliminating livestock open grazing (in the watershed)… We’ve done that with the cooperation of the landowner,” Cox said.
The Conservation Department has also worked with landowners in the watershed to address streambank erosion. And they’ve also done major work on bacteria reduction.
“E. coli in the lake comes from a number of different sources,” Cox said. “Geese are a contributor, livestock is a contributor (which is why they worked to remove livestock grazing in the watershed).”
Another major contaminant they found in the lake through their testing was “optical brighteners,” which are additives in laundry detergent. “That told us there was some kind of connection with residences in the watershed,” Cox said.
With the support of a number of agencies that have been helping with the lake restoration work and with the support of the Story County Board of Supervisors and the Story County Conservation board, Cox said, “we were able to provide a cost share for households with unpermitted septic systems to replace those systems.”
Cox likes to say they’ve worked to “turn off the faucet” on things like optical brighteners and other contaminants coming into the east basin stream and then into the lake.
Major Lake Work
With preliminary projects finished, the major work on the lake itself will begin, and Cox said his department is working in partnership with the Iowa Department of Natural Resources to make improvements for lake accessibility, water quality and the fishery.
The biggest part of the project coming in 2019, he said, is fully draining and dredging the lake. This will be a huge undertaking, especially since the man-made lake wasn’t built with the capacity to drain entirely.
Story County Conservation drained the top 10 feet off the lake (which has a deepest point of 36 feet) to do its cultural and archaeological resources studies this past fall. Those studies involved people from state offices, who came in to assess whether improvements to the lake would affect any cultural/historic resources. Cox said the studies determined that the work could proceed.
To fully drain the lake, so it can be dredged, the contractor on this project will have to employ pumps to get all the water out.
Once fully drained, Cox said the contractor will be doing shoreline work, dredging, creating additional fishing jetties, improving some of the boat launches and creating a new parking area near the main fishing dock on the north side of the lake.
Also planned is enlargement of the island in the middle of the lake. “We’re going to enlarge the island with dredge material and build a bridge from the campground area to the island. It will be really neat,” Cox said.
If there are no hangups with the plans next week, this project will be ready to start in the coming spring or sooner, if weather allows. “We would like to have the lake filled back up in the spring of 2020,” Cox said.
He notes that in addition to the lake work, another project will be happening simultaneously next year, as the beach house will be replaced with a more modern building.
And, there are more improvements to the entire Hickory Grove Park planned for the future. Those improvements include upgrades to the park’s road system, building cabins and expanding the campground to have more camper spaces.
Source: Ames Tribune
