But it will take an extra 1 million gallons per day to assure the hot summer days ahead don't harm fish and other species living in the river, according to Erin Gaskill of the Ohio EPA.
Some area environmentalists say the study shows that the city of Akron's minimum flow is inadequate, and also took exception to the fact that the flow is not guaranteed. Akron could decide not to send any water over the dam if its supplies are critically low.
Akron is proposing to sell water from Lake Rockwell in Franklin Township and Streetsboro to joint economic development districts in Copley, Coventry and Springfield townships. It would be replaced it with water from the Portage Lakes through the Ohio & Erie Canal back to the Cuyahoga, but at points downstream of Kent.
Akron is planning to lease the water it would return to the Cuyahoga from the Ohio Department of Natural Resources. Akron and the ODNR recently signed a lease which calls for 3.5 million gallons a day to be pumped over the dam.
Last week, Kent, Portage County, Silver Lake, Munroe Falls, and Cuyahoga Falls recently filed a lawsuit to stop the diversion and change how Akron operates Lake Rockwell and other dams.
Gaskill said although the study of the entire river is not yet complete, the part of the study which focuses on the area bewteen Lake Rockwell and Waterworks Park in Cuyahoga Falls is.
The study shows that any flow out of Lake Rockwell helps bring up oxygen levels between Lake Rockwell and the Kent Dam, where oxygen levels tend to sag, Gaskill said.
But on the hottest days of summer, when Akron water customers use more water, the river holds less oxygen because of the heat and river flow is lessened because of evaporation, the 3.5 million gallons Akron promises daily probably won't be enough to bring the river into compliance with clean water standards, Gaskill said.
"During a really low-flow day, it would still probably not meet water quality standards," she said. Although the area around the Kent dam would be close to meeting standards, the area upstream of Breakneck Creek probably would be short of oxygen with 3.5 million gallons a day coming from Lake Rockwell.
Gaskill said it would theoretically take 4.5 million gallons a day to bring the area into full compliance during critical days. However, she added, such days are generally uncommon, and she acknowledged Akron has to be careful not to deplete water resources for its customers.
"I'm just happy they're willing to release some water," she said. "It's going to help some of the aesthetics in the Cuyahoga."
Caroline Arnold of the Kent Environmental Council said the KEC is concerned that low flow could cause oxygen levels so low that aquatic life is harmed.
"It only takes one or two days to kill very small organisms," she said. "That reduces the population of larger species because they don't have anything to eat. It really gets to the food chain all along the line."
Because of low flow, she said, organisms go without oxygen at the times they need it most.
"The Cuyahoga River should be a fishable river. It should have a lot of fish in it. It doesn't because it doesn't have the organisms to sustain good quality fish."
She said because of the water study, Akron should promise more than 3.5 gallons of water a day, and make it a guarantee, instead of an agreement that can be changed in the event of a drought.
Ray Flasco, manager of the Akron water plant, said he had seen a draft presentation on the study, but had not reviewed a copy of the study. He said he still doesn't know how much water is assumed to be coming from other wastewater treatment plants, how much flow is assumed from the city's lagoons, and the temperature of the water.
"These all go into the accuracy of the model," he said. "It's a very interesting study, and it's needed, but until we have a chance to review all the assumptions, I can't comment."