Closing St. Anthony lock

[Lee Borgersen]

Agreement reached to close St. Anthony lock in effort to stop invasive carp

Posted: May 15, 2014




MINNEAPOLIS - Fear of a fish will bring an end to continuous navigation on a portion of America’s greatest river.

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In an effort to prevent the advance of invasive carp, Congress appears poised to close the Mississippi River shipping lock at Upper St. Anthony Falls in Minneapolis within a year, Minnesota’s congressional delegation announced Tuesday.

The closure, which could happen as soon as Memorial Day, won’t be a done deal until both the House and Senate approve a larger water infrastructure bill and the president signs it. That outcome, once seen as a political long shot, now appears likely after bipartisan members of the proposal’s conference committee agreed to it.

The carp — silver and bighead carp often called “Asian carp” — are voracious feeders of plankton and can undercut an entire ecosystem, imperiling a range of native fish. A shipping lock, which is essentially a water elevator for boats, can allow the fish to gain access to waters above a dam, so closing the lock is seen as one of the most effective barriers to prevent the carp from invading farther upstream.

Thus far, the fish aren’t known to have established themselves in Mississippi River waters in Minnesota, but they have been advancing, and carp eggs were found this winter in the river below Lock and Dam No. 8 in Genoa, Wis., so they’re finning at the doorstep. Many biologists believe if carp establish themselves, they’ll be nearly impossible to eradicate.

While the two locks at Upper and Lower St. Anthony Falls are the least used of the 29-lock navigational staircase between the Twin Cities and Granite City, Ill., the bipartisan agreement in Congress drew praise from supporters. They include Minneapolis Mayor Betsy Hodges, the Minnesota Department of Natural Resources, Trout Unlimited, the Minnesota Division of the Izaak Walton League and Friends of the Mississippi River.

“It shows you what leadership can do when they get focused on meaningful action,” said Whitney Clark, executive director of Friends of the Mississippi.

But it’s not without costs.

The St. Anthony locks, built in the 1950s, are used by a handful of industrial companies to haul barge loads of material upriver.

Among them: tens of thousands of tons of rocks used as aggregate to make concrete for much of the construction work in downtown Minneapolis, including the new Vikings stadium.

Eagan-based Aggregate Industries regularly ships pairs of barges, each carrying some 1,200 tons of material, from its hub near St. Paul’s Homan Field to its yard in Minneapolis. Its largest customer is Cemstone, whose concrete mixers are a construction-site fixture.

“Concrete is a perishable product,” said Tim Becken, a senior vice president for Cemstone. “Typically, you only haul this product for 25 minutes to a half-hour, so you need to make it close to where you’re going to pour it. It’s the Vikings stadium — you can see all the concrete being poured right now on the webcams — it’s apartments, it’s buildings, you name it.”

So the aggregate needs to get to Aggregate’s yard one way or another — or the yard needs to be moved, Aggregate and Cemstone have said. Rail isn’t an option along the route, so the material would need to be hauled by trucks, an estimated 20,000 additional one-way truckloads annually, according to Aggregate’s estimates.

“And it’s quite a bit more expensive than using barges,” said Becken, who didn’t have specific estimates. He emphasized he’s not opposed to closing the locks, but he said the companies will lobby to be compensated, and the public should expect more heavy truck traffic.

Within the past two years, a number of lock-users have reduced or eliminated their lock use to lower the chances of carp swimming through. Several entertainment cruise boats have relocated below the falls, and recreational boaters, encouraged by river advocates, have reduced their use. More than a year ago, the National Park Service, Wilderness Inquiry and Friends of the Mississippi ceased taking flotillas of canoes through the locks as part of popular river tours.

“We took hundreds of people through there every year to access the Mississippi River Gorge (between Minneapolis and St. Paul), and we miss it,” Clark said. “But sometimes you have to make choices.”

The congressional action was spearheaded by U.S. Sen. Amy Klobuchar, who attended several “carp summits” convened by Gov. Mark Dayton.

“The spread of invasive carp poses a major threat not only to Minnesota’s environment, but also (to) the recreation and fishing industries that help power our state’s economy and create jobs,” Klobuchar said in a statement. She was joined by Sen. Al Franken, and Reps. Keith Ellison, Erik Paulsen, Tim Walz and Rick Nolan.

Closing the locks, scientists say, should bring security to waters upstream, although it’s not the only protection.

Work is expected to be completed this year on a rehab of the Coon Rapids Dam that will make it a more effective barrier, though fish still could swim past the structure during severe floods. Above Coon Rapids lies the Rum River, the outlet of Lake Mille Lacs, one of the state’s most important fishing lakes.

A number of dams farther upstream on the Mississippi likely would hinder the fish’s advance through the heart of Minnesota’s fishing and boating waters toward the river’s headwaters of Lake Itasca.

The closure of the lock is expected to raise a question of what will become of more than $10 million the DNR was moving forward with spending to build an electrical, light and sound barrier below the Ford Dam in St. Paul, also known as Lock and Dam No. 1.

And farther downstream, University of Minnesota professor Peter Sorensen, a carp researcher, has a $60,000 plan to install underwater speakers as a carp-deterrent below Lock and Dam No. 8.

Many observers believe the key battles against the invaders must be fought in southeastern Minnesota before the fish have access to the Minnesota River — believed to be prime habitat for bighead and silver carp — and the St. Croix River.

“Closing the lock is really helpful for all the waters above St. Anthony Falls,” Clark said. “But for all the waters below the falls, this does nothing. We still have a lot of work to do.”