By Dave Orrick

Armed with proposed federal legislation and a fresh discovery of more invasive carp in the Mississippi River, state and federal lawmakers in Minnesota are pushing to close the shipping lock at Upper St. Anthony Falls in Minneapolis.

"I see no reason why we can't close it," U.S. Sen. Amy Klobuchar said during a "carp summit" convened by Gov. Mark Dayton on Wednesday, Feb. 20, at the state Capitol.

Closing the lock would be the first concrete action taken to thwart the spread of bighead and silver carp up the Mississippi.

Wednesday was the fourth carp summit, but the lack of action has frustrated many, including fishing groups and the state's congressional delegation.

Officials are examining installation of an electric or acoustic fish barrier below the Ford Dam in St. Paul. But no barrier can be built before the 2013 shipping season, which originally was the goal.

On Wednesday, Klobuchar and others chided the U.S. Army Corps of Engineers, which controls the Mississippi River locks system, for being a bureaucratic obstacle.

Klobuchar leveled her criticism as Tom Crump, the agency's regional planning chief, explained that only Congress has the authority to close the Upper St. Anthony Falls Lock.

"Is the corps in favor of our bill to speed things up?" Klobuchar asked.

"The corps does not comment on pending legislation," Crump responded.

Klobuchar chuckled. "I understand, but you've raised issues with our bill, and if you said it was a good idea, it would help us out a lot."

Klobuchar was referring to bipartisan legislation introduced by Minnesota's delegation last week in Congress that would force the corps to begin the closure process.

Crump responded: "There are benefits and costs to it ... and we need to weigh them."

With an elevation change of 49 feet, the Upper St. Anthony Falls Lock and Dam is the penultimate barrier to stop invasive carp from reaching the inland waters in central Minnesota, including the Upper Mississippi River and Lake Mille Lacs.

The lock has been targeted by lawmakers and top officials who believe it's a matter of time before the fish swim amok. State Department of Natural Resources Commissioner Tom Landwehr said Wednesday that two adult bighead carp had been discovered in a fishing net near Winona, "underscoring the urgency."

No live fish have been found above the Ford Dam in St. Paul.

Silver and bighead carp are voracious plankton feeders that have infested American waters south of Minnesota, where the fish have crowded out native fish and other aquatic life. Silver carp, known for their spectacular leaps from the water when agitated by boats, commonly reach 20 pounds and pose a serious safety threat to boaters.

Unlike almost any other fish in this portion of the Mississippi, bighead and silver carp tend to migrate against the current. Every time the lock opens to allow a boat through, water from the lower river is brought to the upper river -- and with it, potentially, carp.

Although the process of closing the lock could take more than a year, many summit participants are pushing a de facto closure by limiting who can use it.

"We can do this right now -- immediately," said Dave Zentner, former national president of the Izaak Walton League and a member of the Stop Carp Coalition, which includes an assortment of lake and river associations, fishing groups and environmental advocates.

The coalition supports paying businesses affected by a lock closure. The potential costs of doing nothing, they argue -- both environmentally and for the state's tourism industry -- are far greater. Recreational boaters could agree to voluntarily stop using the lock in the name of protecting the river.

That process appears to have started.

Three ports operate upstream from the lock. One, owned by the city of Minneapolis, is scheduled to close when a contract to operate it expires in the next two years, said Peter Wagenius, policy director for Minneapolis Mayor R.T. Rybak.

The other two ports are privately owned.

One of the businesses that uses the locks and one of those ports, construction materials company Aggregate Industries, relies on it to haul sand and gravel upstream. Bob Bieraugel, manager of environment and land services for Aggregate, said the company has proposed altering its schedule to reduce the hours the lock is open.

When asked whether the company would be open to essentially having its upstream operations bought out, he responded, "Sure."

Wagenius said representatives of Cargill, which occasionally uses the lock to ship to a site above the lock and dam, have told the city they wouldn't be opposed to moving operations downstream.

Most vessels that use the lock are recreational boats, but their numbers are declining as well. The Minneapolis Queen, which makes hundreds of trips annually with its tour boat, stopped using it last summer, following a decision by Wilderness Inquiry to avoid the lock during its canoe tours.

"As far as I know," Klobuchar said," that leaves a bunch of kayakers, and I'm prepared to lose their support if that's what it takes to close the lock."

On Wednesday, Landwehr said the DNR would revisit its position on a fish barrier below the Ford Dam, also known as Lock and Dam No. 1.

Consultant Barr Engineering had recommended a $19 million acoustic and bubble barrier, but lawmakers criticized its effectiveness of lower than 90 percent.

Barr had discounted the idea of an electric barrier, which would likely be more effective, as being unsafe and unlikely to pass Corps of Engineers' approval.

But Geoffrey Griffin, a former DNR employee who now serves as CEO of Chatfield engineering firm G-Cubed, has swayed some lawmakers to his proposal of a lower-power electric barrier that would be safer and do less damage to the infrastructure.

Landwehr said the DNR would direct Barr to examine Griffin's plan with a goal of presenting it to the corps for possible approval, but he noted that "the window has closed" for getting any barrier built before the 2013 shipping season.