DNR, Watershed District differ on dredge scope

Published 9:39 pm Tuesday, November 7, 2017

Watershed officials requesting more information on DNR view

The final Fountain Lake dredging permit request came back from the Department of Natural Resources with a smaller-scale project approved than the Shell Rock River Watershed District requested.

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The dredge the district requested would move about 600,000 cubic yards of sediment in the first phase of the project, while the DNR has approved approximately 400,000 cubic yards.

“According to their (bank) setbacks and what they’re proposing, our engineers went back to figure the volume, and yeah, they are reducing it by 200,000 cubic yards,” Shell Rock River Watershed District Administrator Brett Behnke said Friday.

The Shell Rock River Watershed District has filed a data request with the DNR to better understand the way the DNR has made its dredging decisions. The watershed district has been trying to work through areas of concern since receiving back a draft permit in July.

“Because of continued delays, we feel we need to be proactive in gaining critical information from the DNR that may be driving their decision-making process,” said Andy Henschl, district project manager, in a press release.

Behnke said the Watershed District is struggling with the science behind the DNR’s most recent decision.

“There’s not good science behind their justifications for their movement from our original plan,” Behnke said.

According to both Behnke and Ecological and Water Resources South Regional Manager Robert Collett with the DNR, some of that science involves the littoral zones, or the lake edges, of Fountain Lake.

“There’s sort of balance, sort of options with the size of the project and what the impacts are,” Collett said. “So right now, Fountain Lake is actually doing quite well in its fishery and then we know we have Blanding’s turtles there, so one of our goals, I guess, as we review this project is to protect the littoral area.”

Behnke said the DNR has asked for a greater setback from the shore and less volume off the bottom of the lake.

“Even trying to protect that near-shore area and not dredge there, I don’t think we’re missing out on a lot of sediment because it’s already fairly deep there,” Collett said. Additionally, he said pulling less sediment from the bottom of the lake was to be careful that deeper pockets of the lake did not end up without oxygen in the winter because the water would be isolated, impacting its ability to mix well and decreasing water quality.

Behnke said Friday that the DNR has not given the Shell Rock River Watershed District access to the science it used to justify a dredge size modification.

“When it comes to dredging, the state has no handbook for how we can and cannot do this,” Behnke said. He called the Shell Rock River Watershed District “pioneers of the dredging world in these prairie lakes.”

Collett said there are not many dredging projects across the state, but there is a defined set of rules.

“Every project, every lake is different, but we’re using the same set of rules to kind of guide us in the permit decision,” Collett said.

Although the DNR has approved a smaller dredge than the Shell Rock River Watershed District was requesting, Collett said the decision was not necessarily about the dredge size.

“I wouldn’t say it’s too big,” Collett said of the watershed district’s proposal. “It’s just making sure it’s designed right. We’re in charge of looking at the big picture from a higher level, and that’s kind of what we’re doing.”

Additionally, Collett said he did not see the size decrease creating the potential need for a second dredge.

“To say, ‘Oh, we didn’t dredge enough, we’ve got to go back and dredge again,’ I don’t think that’s a valid concern,” he said.

Collett said the difference between what the DNR and the watershed district see as best for the lake could be based on a different idea of what the lake looks like and needs. As part of its evaluation, the DNR did soundings of the lake to create a bathymetric map, which gives a picture of what the lake’s terrain looks like in size, shape and feature. The watershed district has also conducted evaluations of the lake, which it submitted with its permit request.

Behnke stands behind the science the Shell Rock River Watershed District submitted to the DNR.

“Ultimately, we’ve proven that we’re preserving the ecological standard of the lake,” Behnke said. “That’s what’s so frustrating.”

The first cell of the confined disposal facility that will house the dredged sediment is almost complete, and the watershed district intends to begin dredging in 2018.

After receiving the permit back from the DNR with a different dredge size approved than what was requested, representatives of the watershed district and the DNR met Friday to discuss the parameters of the dredge.

“After the meeting (Friday), I feel that there’s progress in the right direction,” Behnke said. “They’re making movement, we’re making our point, but there’s still a long road ahead of us.”

The Shell Rock River Watershed District will meet Thursday morning to discuss the Fountain Lake restoration and receive a dredge permit update from Director of Field Operations Andy Henschel.

About Sarah Kocher

Sarah covers education and arts and culture for the Tribune.

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