CLEVELAND: The U.S. Army Corps of Engineers is kicking off a new study to determine how the Gorge Dam between Akron and Cuyahoga Falls could best be removed and how to deal with sediment behind the dam.
Mandy Razzano of the Ohio Environmental Protection Agency offered an update on the dam Thursday at a two-day State of the River symposium on the Cuyahoga River.
The Corps review will take at least 18 months to complete, EPA spokesman Mike Settles said.
The study will be funded by a $500,000 federal EPA grant, plus $323,000 of in-kind services provided by the Ohio EPA plus local partners, he said.
The Corps report will look at how the dam might best be removed and what to do with it, Settles said. It will also look at sediments behind the dam, how to best manage them and where to put the sediments.
The Corps will also develop a flow model for what the Cuyahoga River would be like, if the dam were to be removed, he said.
An analysis would also provide a firm cost estimate for the dam removal for the first time, Settles said.
The report is expected to offer a number of detailed alternatives, he said.
The review is in the early stages.
No decision has been made to remove the concrete dam that is 68 feet high and 429 feet wide. But the Ohio EPA would like to see the dam in the Gorge Metro Park removed to boost water quality on the Cuyahoga River.
Estimates are that at least 832,000 cubic yards of sediment are behind the dam. That’s enough to fill the Akron Rubber Bowl four times.
The average sediment depth behind the dam is 15 feet and the maximum depth is 28.5 feet, according to a study done for the U.S. EPA.
The sediment volume was determined by two studies conducted by the U.S. EPA in September 2009 and July 2011 in the 34-acre reservoir that stretches 1.4 miles behind the dam.
Tests revealed moderate levels of contamination but no major toxic problems.
The key contaminants were lead, cadmium and polynuclear aromatic hydrocarbons, Razzano said.
Removing the dam could cost $5 million to $10 million with another $15 million to $20 million for sediments, according to preliminary estimates. But the volume of sediments is twice what had been expected and that is likely to boost the final cost estimate, Settles said.
Federal funds could cover 65 percent of the sediment costs. The local share could be covered with in-kind services and contributions from state, county and local agencies plus FirstEnergy Corp., which owns the dam.
In other action, the removal of two dams in Cuyahoga Falls was hailed as “the greatest victory” on the Cuyahoga River in 2013, said Jane Goodman, executive director of the Cuyahoga River Community Planning Organization.
The Sheraton Mill Dam came down in July and August and the LaFever Dam was removed in mid-August after lengthy weather-related delays, said Joel Bingham of RiverWorks, the consortium that removed the dams.
Now the project, he said, is in “an assessment phase.”
He said he is keeping an eye on the silt that extends upstream in the Cuyahoga River from the dams to Waterworks Park. It is starting to be washed downstream by rains. That is changing the flow along the river, he said.
The companies intend to further analyze what’s happening with the flow and to study bank erosion along the narrower river, Bingham said. Recommendations will be made to Cuyahoga Falls, which sponsored the $1 million dam removal.
In other news, the Army Corps of Engineers said the toxicity of sediments in the Cuyahoga River in the 5.8-mile Shipping Channel through the industrial Flats continues to decline.
Tests in 2013 show that the toxicity is continuing to drop, compared to tests in 2007 and 2010, spokesman Scott Pickard said.
That could make it possible to dump the 250,000 cubic yards of sediments dredged from the channel to be safely dumped into Lake Erie, he said.
At present, the sediment must go into special storage facilities on the Cleveland waterfront.
Champions of the River awards were given to Cuyahoga Falls and three individuals.
The city was saluted for the dam removals. Also honored were Elaine Marsh of Bath Township, a founder of the Friends of the Crooked River, a grass-roots group involved in the Cuyahoga River; John Debo, former superintendent of the Cuyahoga Valley National Park; and Virginia Aveni of Lyndhurst, an early advocate for the Cuyahoga River.
Bob Downing can be reached at 330-996-3745 or email@example.com.