News last week that the Department of Natural Resources wants to build a bubble and sound barrier on the Mississippi at Lock and Dam 1 in the Twin Cities to prevent Asian carp from swimming farther upstream arrived simultaneous with news the agency believed an electric barrier at the same site would be impractical.

The DNR's original plan, or idea, was to install an electric barrier at Lock and Dam 1 (also known as the Ford Dam) similar to the electric barriers placed in the Chicago ship canal to prevent Asian carp from entering Lake Michigan.

But the agency's contract engineering firm determined an electric barrier in the Twin Cities could be dangerous to boaters while also threatening to corrode the lock.

Thus the bubbler and sound idea, and the DNR says as much as $19 million will be needed to build it, in addition to $1 million to design it, not counting money already spent developing the proposal.

Whatever threat any of this ultimately presents to Asian carp, the state's taxpayers should feel threatened, if not cheated.

That's because the far better, easier, cheaper and more effective alternative to dissuade invading carp from infesting northern Minnesota waters would be to close the lock at Upper St. Anthony Falls, if not also the one at the Ford Dam.

Even absent that, a still better idea than building a sound and bubble barrier at Lock and Dam 1 would be to place a similar structure near Keokuk, Iowa, at Lock and Dam 19.

That way, protection the DNR hopes to afford the Upper Mississippi River also could be afforded the Minnesota and St. Croix rivers and their tributaries, as well as the Chippewa and other rivers that spill into the Mississippi from Wisconsin south of the Twin Cities.

It's true that the DNR is limited in its influence over the St. Anthony option. Closing the lock there ultimately would take congressional action, beginning first with agreement by the state's U.S. senators and representatives, acting in unison in an attempt to influence their colleagues and, as importantly, to strong-arm the Army Corps of Engineers.

It's true as well that the relative handful of barge operators and others who ship gravel and other products through the Ford and St. Anthony locks would be hurt by a closure. And I appreciate the political muscle they and others -- including the Corps of Engineers, whose lifeblood is keeping shipping channels open, not closing them -- can offer in resistance.

But it's absurd that the billions of dollars at stake in the state's northern Minnesota resort and tourist industries, not to mention the lifestyle the lakes and rivers upstream of the Twin Cities afford everyone who lives here, can be trumped by a small business contingent and the bureaucratic whims of a federal agency.

The DNR's share of the blame here pales in comparison to that of Minnesota's congressional delegation, which seems on this issue curiously ineffective.

Go figure.

But go figure as well that the DNR again in this instance has failed to reach out to educate and persuade Minnesotans on behalf of the resources it has pledged to protect.

Build a sound and bubble barrier that might work or -- perhaps as likely -- might not?

That's an easy one for the DNR to get behind.

Part I: Hire an engineering firm to study the issue.

Part II: Use the firm's report to justify handing a $20 million invoice to the Legislature.

Far more difficult for the DNR to propose vigorously for closing the affected locks, even though that's the better option.

Doing so, after all, might rub the wrong legislator the wrong way, causing him or her to exact a price, politically, the DNR is unwilling to pay.

Instead, it's up to the state's conservation groups, as well as the National Park Service, to argue for that rational and best option.

Which they have done.

The problem, ultimately, is systemic.

For too long, the DNR has been kept on too short a leash by the Legislature, until now each relies on the other to validate paths of least resistance.

For this, the state's resources have paid a price that might now be poised to rise exponentially higher.

Dennis Anderson • danderson@startribune.com