MINNEAPOLIS -- Just upstream of the small northwestern Minnesota community of Lake Bronson stands a deteriorating old dam considered the most dangerous in the state.
"If it fails under flood conditions, it will inundate more than a dozen homes in (the) nearby City of Lake Bronson with little warning to allow for evacuation," according to a June memo.
"It will also contribute to flooding of several hundred homes, schools and commercial structures at Hallock."
In a state not far removed from the trauma of the Interstate 35W bridge disaster, an Associated Press review found a new concern: Minnesota's dams. A review of state records and interviews with officials found that even when dams have serious known flaws that could cause loss of life and major property damage, it can take years to fix those problems.
The Lake Bronson Dam is at the top of the Minnesota Department of Natural Resources' priority list, yet any major work to renovate or replace it is likely years away.
ADVERTISEMENT
Still, Kent Lokkesmoe, director of the DNR's Waters Division, who sent the memo, said he's confident that neither Lake Bronson nor any of the 1,150 other dams the DNR regulates are an immediate risk to public safety.
"If I thought there was any imminent threat of failure, I wouldn't hesitate for one minute to order the pool lowered," he said.
Agency files show that the Lake Bronson and New London dams have been the DNR's biggest causes for concern for some time.
The Legislature in 2006 put $2 million in that session's bonding bill for a study of what needs to be done in New London, but that work has been stalled and a consultant to do it has yet to be hired, Boyle acknowledged.
The DNR's 2008 request covers 14 dam safety projects, topped by $400,000 for a similar study for the Lake Bronson Dam. As for the New London Dam, Lokkesmoe said, the money for actually renovating or replacing it would likely have to wait for the 2010 bonding bill.
"I'm not sure yet if it's a $2 million project or a $4 million project," he said.
The AP review found:
n The DNR has not kept up with the inspection schedules laid out in agency regulations. It's current on the dams that would pose the biggest risk to people and property if they failed, but inspections are overdue on close to 700 others. There's no consequence for being behind in inspections because of a loophole that makes them "subject to the availability of staff and funds."
ADVERTISEMENT
n Minnesota's average inspector is responsible for more than 330 dams. The Association of State Dam Safety Officials recommends fewer than 50 dams for each inspector.
n When inspections show a dam needs major repairs or replacement, the process of studying the problem, deciding on a solution and getting the work done is often slow.
n The state isn't meeting federal guidelines that recommend that dam owners conduct periodic tabletop exercises to check the emergency plans for dams that have them.
n The Federal Energy Regulatory Commission, which oversees 32 hydroelectric dams in Minnesota, ordered reservoirs drained and round-the-clock monitoring at two old dams near Mankato and Pillager this summer. Work continues to repair a large void that was found underneath the Rapidan Dam south of Mankato, while further inspections determined that the Pillager Dam west of Brainerd was safe.
Minnesota is just one of many states that's been overwhelmed by the "enormous burden" of ensuring their dams are safe, said Brad Airossi, legislative chairman of the Association of State Dam Safety Officials.
The American Society of Civil Engineers, which issues report cards on the nation's infrastructure, regularly gives America's dams a D, while bridges get a C. It says more than $10 billion is needed to address all the critical issues at state-regulated dams across the country.
Dams fall into three categories: high hazard, medium hazard and low hazard. The terms don't refer to the condition of those dams, but the potential threat to people and property if those dams were to fail.
According to Airossi's group, 1,333 high-hazard dams across the country are structurally deficient or unsafe, and the average dam inspector is responsible for more than 400 dams.
ADVERTISEMENT
"Most of the dam safety programs in the United States are underfunded and understaffed," said State Dam Safety Engineer Jason Boyle, who leads Minnesota's program.
Many of Minnesota's dams were built in the late 1930s by the Works Progress Administration, a Depression-era federal program.
"They are 70 years old. Some of them need to be repaired. Some are showing their age. Most of them, fortunately, are the low-hazard dams," Boyle said.
The DNR spends a little over $300,000 per year on its Dam Safety Program, most of it to pay engineers' salaries. Project funding typically comes through state bonding bills and from local governments when they own the dam. The DNR has requested $3 million for 2008.
The DNR's Lokkesmoe said he believes the state's current spending on dam safety is adequate. He said the DNR plans to catch up on the inspections in two years, then put all the dams it monitors on a regular schedule.
And Lokkesmoe said the DNR's 43 field hydrologists watch dams in their areas and notify the dam safety engineers of anything unusual.
"You don't need a registered engineer to see if a culvert's rusted or there's a tree on the embankment," he said.
------
ADVERTISEMENT
On the Net:
Minnesota Dam Safety Program:
http://www.dnr.state.mn.us/waters/surfacewater--section/damsafety/ind ex.html
National Inventory of Dams: http://crunch.tec.army.mil/nidpublic/webpages/nid.cfm
Association of State Dam Safety Officials: http://www.damsafety.org
Dam Safety Coalition: http://www.damsafetycoalition.org
Barr Engineering site on Lake Bronson Dam feasibility study: http://www.barr.com/lakebronson
