Study goes over dam options

Dam feasibility study continues

By Sam Wildow - Miami Valley Today

PIQUA — The U.S. Fish and Wildlife Service, in conjunction with the cities of Troy and Piqua, held the second public meeting to update residents and interested stakeholders about the Dam Modification/Removal Feasibility Study on the Great Miami River at the Upper Valley Career Center on Wednesday evening.

A 2017 U.S. Fish and Wildlife Service grant was awarded to the Miami Soil and Water Conservation District to explore the possibility of dam removal or modification of three dams in the city limits of Piqua and Troy, two of which are in Piqua, along the Great Miami River.

Representatives from the U.S. Fish and Wildlife Service and consultants from FlatLand Resources, LLC presented more information about the study on Wednesday, as well as going over the different types of modifications that the cities can implement with their dams. They will provide their recommendations to the cities of Piqua and Troy during a third meeting, the date of which is still to be determined.

David Heilman of FlatLand Resources, LLC discussed the benefits of modifying or removing dams as it impacts the surrounding environment and recreational purposes on the river, addressing a number of the interests and uses that attendees brought up at the previous public meeting on the study in March.

Heilman said that dams can create a lack of biodiversity in streams, impact the fish population, and create “mud flats” from sediment buildup.

Mike Porto, a fisheries biologist with the Ohio Division of Wildlife under the Ohio Department of Natural Resources, talked about monitoring the sport fish populations in the Great Miami River.

“We’ve done surveys up and down the Great Miami River the last two years,” Porto said. In 2017, they sampled the lower portion of the Great Miami River, which was south of Dayton, for portions of smallmouth, largemouth, and spotted bass. In 2018, they sampled the upper section of the river from Dayton up to Sidney.

Porto said that they found that the catch rates for those types of bass were “much higher” in the upper river versus the lower river with a catching rate of 15.5 fish per site in the upper river compared with 6.8 fish per site in the lower river. There was 81 percent smallmouth bass in the lower river compared to 95 percent smallmouth bass in the upper river.

Porto said removing dams would would remove barriers to fish migration and would “only help” when its their time to spawn.

“I think, overall, the fishing will be just as good,” Porto said.

Heilman then went over the safety concerns regarding low head dams, showing a PBS video about how they can turn into “drowning machines” where individuals can get caught in the current.

“They are a death trap,” Heilman said.

Heilman also went over how recreational river use has increased in the past decade, saying, “Water pattle sports have really taken off since 2008.” He said that canoeing and kayaking is a $6 million industry in the U.S., adding that has increased approximately 42 percent since 2008. He added that biking and fishing is a $1 billion industry across the U.S.

Heilman then went over different modication options for the dams in Piqua and Troy. There is one dam in Piqua that is still serving an infrastructural purpose, so it cannot be removed.

“First option is to do absolutely nothing,” Heiman said. He said that there would be no increase to biological health and the cities will maintain their same maintenance costs.

“It doesn’t necessarily address the recreational desires of each city and town … nor is it addressing the safety issues,” Heilman said.

Heilman then mentioned constructing a fish ladder, which he later said was not a viable option for the dams in Piqua and Troy.

“These are typically most effective in cold water systems,” Heilman said. “The Miami River is a warm system.”

The next dam modication idea Heilman went over was a constructed rock riffle, where the cities would use boulders and rocks building a riffle, or a shallow landform on the down stream side of the dam. He said that the size of the boulders and rocks would be based on the velocity of water. The faster the velocity, the larger the stones need to be, he said.

Heilman said that the cities could also choose to do a partial or full dam removal, which would have more upfront costs.

For a full dam removal, Heilman said that there is the concern of the release of the sediment buildup behind the dams, such as if there were any harmful toxicants in those sediments. They provided samples of the sediments behind the Piqua and Troy dams to the Ohio Environmental Protection Agency (EPA) for testing, who then responded saying that their tests did not indicate that the sediments would be harmful.

Environmental Scientist Vanessa Steigerwald Dick, Ph.D., of the EPA sent back the following statement:

Based on an analysis of the sampling results and relatively low concentrations of chemicals detected, adverse effects are not expected to occur to ecological receptors from exposure to the sediments. In addition, a conservative comparision of the sediment concentrations of chemicals detected to U.S. EPA Regional Screening Levels (RSLs) for residential soil does not indicate potential human health concerns.

Heilman said they cleared a “major hurtle” by getting that response from the EPA.

Representatives from FlatLands Resources are expected to give their recommendations on way the cities of Piqua and Troy should do with those dams at other meeting that is still to be determined.

Dam feasibility study continues

By Sam Wildow

Miami Valley Today

Reach Sam Wildow at © 2019 Miami Valley Today, all rights reserved.

Reach Sam Wildow at © 2019 Miami Valley Today, all rights reserved.