Many things must be done to cleanse western Lake Erie and prevent a recurrence of this month’s water emergency in Toledo. Handled properly, the proposed demolition of the deteriorating, century-old Ballville Dam that spans the Sandusky River near Fremont could help promote the cleanup effort.
Done incorrectly, though, the dam removal could worsen the blooms of algae in the lake, which generate the toxin that poisoned Toledo’s water supply for several days. So the local, state, and federal officials who will decide whether and how the dam will come down need to get both matters right the first time.
The Ballville Dam, completed in 1913, was built to generate hydroelectric power; its function evolved over time to providing Fremont with water. The city has a new reservoir, but it has been plagued by cost overruns and other problems.
Fremont officials are expected to vote this fall on removing the dam, which has not been upgraded since the 1960s. State and federal grants would pay for most of the expense of demolition.
Proponents say taking down the dam would improve both the flow of the Sandusky River — a major tributary of Lake Erie — and the region’s fish habitat. The Ohio Department of Natural Resources and the U.S. Fish and Wildlife Service advocate dismantling the dam in stages over several years.
But environmental groups warn that the demolition would release a massive amount of phosphorus-laden sediment that is trapped behind the dam into the river, Sandusky Bay, and ultimately Lake Erie. State and local officials say that dredging and removing the sediment would be prohibitively expensive.
Such silt feeds algae growth. That doesn’t have to happen, though, if wetlands near the dam site are expanded and enhanced, so they can adequately filter phosphorus pollution. The trapped sediment can help seed wetlands.
The Ohio Environmental Protection Agency would be responsible for certifying that the wetlands activities are appropriate. Before the agency does so, it needs to have — and communicate — a clear idea of the effect of sediment release on the river and Lake Erie; that will require appropriate study and testing.
Ohio EPA also will have to monitor water quality while the dam is removed; the agency says it does not now intend to take water samples before or during demolition. And it will need a plan to stop the release of sediment if it is found to add significantly to pollution in the watershed caused by farm runoff, which has caused chronic problems for Fremont.
So far, Ohio EPA’s response to the Toledo water crisis has been inadequate, building on voluntary anti-pollution measures that haven’t done enough to prevent toxic algae growth in Lake Erie. If the agency takes a similarly hands-off approach to the dam removal, the U.S. Army Corps of Engineers must be ready to use its permitting authority to require that meaningful steps to mitigate pollution during the process are followed.
A new study by the Fish and Wildlife Service concludes that demolishing the obsolete Ballville Dam and allowing the Sandusky River to flow more freely would improve water quality in Lake Erie. It also could boost the region’s economy.
But done carelessly or on the cheap, the dam removal would make things worse. That can’t be allowed to happen.