Tuesday, February 23, 2016

UPDATED Harpersfield dam's $6 million replacement to be most costly such Great Lakes project

Long talked about as being a crumbling structure, the 115-year-old Harpersfield Dam on the Upper Grand River is now on the federal funding docket as a $6 million reconstruction objective in order to keep the invasive sea lamprey at bay.

As such, the project will become the most expensive such operation anywhere on the Great Lakes.

Located on the Grand River in Ashtabula County’s Harpersfield Township and a couple miles south of Interstate 90, the once-waterworks dam is fused in an historical and tourism pas de deux with the adjacent Harpersfield Covered Bridge, both of which make up a 26-acre unit of the Ashtabula County Metroparks system.

The existing concrete dam – ground-penetrating radar noting the dam’s crest is actually hollow along the structure’s entire 325-foot length - is slated for partial demolition late next year, and following final design and outsource construction bidding. Its replacement will likely see completion at some point in 2018.

All of this in order to assure that breeding adult sea lamprey cannot bypass any fallen structure and access the stream and its tributaries above the impacted site. A federally funded study suggests that the coupled mileage of the Grand River trunk and its many tributary branches could potentially offer up to 1,266 miles of habitat for sea lamprey production.

Indeed, the Corps of Army Engineers’ report concludes that existing cracks in the dam’s decaying body may even now allow for sea lamprey intrusion into the Upper Grand River Watershed.

“Harpersfield Dam currently serves as an unreliable barrier to the upstream migration of the invasive sea lamprey due its sloping downstream face and (the) lack of a horizontal lip at its crest,” says the Corps’ 16-page public presentation document.

Yet the Harpersfield Dam represents something of an anomaly to the rule that dams – regardless of their age, historical or recreational value – are more than just eyesores. They are structures which impede the natural migration of aquatic wildlife, particularly fishes and as such are typically deemed worthy only of the backhoe and the dozer.

This exceptionalism is exactly the reason why a new Harpersfield Dam is expected to be anchored almost foot-for-foot where the present century-plus-old structure is found, says federal and state wildlife officials along with the Corps.

“The thing is, that nursery water for the invasive sea lamprey is exceptional above Harpersfield Dam,” said Phil Hillman, fish management supervisor for the Ohio Division of Wildlife’s District Three (Northeast Ohio) Office in Akron. “That has been everyone’s overriding concern.”

And that concern also involves money. It costs the Great Lakes Fisheries Commission $127,000 to treat the Grand River every three to four years with a lampricide. Tear down that Grand River barrier and this expense would mushroom to more than $460,000; a due-bill the federal government would find staggering.

All of which is especially true given that the Grand River now stands atop the heap as Ohio’s Number One sea lamprey nursery, even without the additional mileage that is potentially racked up above Harpersfield dam.

So destructive is the sea lamprey that federal fisheries biologists estimate than an adult can destroy up to 40 pounds of fish in the predator’s lifetime. It does this by using its circular mouth that contains concentric rows of teeth that latch on to a fish’s body and then proceeds to employ its rasping tongue to consume its host’s flesh.

And because the sea lamprey has no natural enemy in the Great Lakes, if left unchecked it can – and has - play havoc on the system’s fish populations.

“Up until now we’ve been pretty successful in controlling the sea lamprey in the Grand River but we have concerns about the dam’s condition,” said Jessica Barber, a fisheries biologist with the U.S. Fish and Wildlife Service.

Barber said those concerns focus on the structure’s grizzled centurial age and the simple fact that nothing stands forever; certainly not a manmade structure that’s withstood annual ice jams, flooding, and pummeling by countless trees ripped from their streamside moorings and shipped off down the Grand River.

“The north abundment is most in danger of failing,” Barber said as well.

Corps project manager Kennth E. Podsiadlo says that initial design concepts point to shaving off the structure’s hollowed-out crest. All of the existing base will likely remain in order to support a new upper structure which will probably extend slightly upstream and include a lamprey-impeding six-inch steel downstream-facing “lip,” Podsiadlo says.

“The design is still being worked on by our design crew but the height should be about what it currently is; again, based on what our design team determines,” Podsiadlo says.

However, any trout that can catapult itself above whatever structure is secured bank-to-bank won’t need to navigate much of the silt and rich farm spoil that the dam has held back since Theodore Roosevelt began occupying the White House following the assassination of President William McKinley of Ohio.

The reason being, says Barber, is because the project will include scooping out the above-dam mucky goo and transporting it offsite.

“So there will be minimal downstream impact from silt,” she said.

In regards to funding, the check is being picked up by the federal government from two distinctly different pots. Those outlays will include a current estimate of $2.1 million from the Great Lakes Fisheries Commission – which is supported by both the United States and Canadian federal governments - and the remaining $3.9 million from the Corps’ Congressionally approved Great Lakes Restoration Initiative account, both Barber and Podsiadlo say.

“This is a something that is absolutely necessary,” Hillman said also, thusly noting that the cost of doing nothing will only favor the invasive sea lamprey.

By Jeffrey L. Frischkorn

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