Scores of inspection stations would be needed to lower the risk that zebra mussels will spread. Annual cost: $10 million to $28 million, and possibly more.
The state is looking at a range of scenarios for protecting lakes from the spread of zebra mussels, including a plan that would have state inspectors tag boats as clean or potentially contaminated based on which lakes they've been frequenting.
The study could have major implications for boaters who use Prior Lake, considered one of the most infested lakes in the state, as well as 28 other lakes in Minnesota where zebra mussels have been confirmed.
A consultant for the Department of Natural Resources looked in detail at three lakes -- Minnetonka, Mille Lacs and the Gull Lake chain near Brainerd -- and outlined a plan for Hennepin County as a whole to show how extensive an inspection program would have to be to contain zebra mussels.
Hennepin County alone could need 34 centralized boat inspection stations -- including 12 around Lake Minnetonka -- to prevent the spread of zebra mussels, the consultant concluded. The study estimated that 300 stations would be needed statewide; Hennepin County would need the most because of its large population and high use of public and private boat accesses.
The study estimated the annual price of centralized inspection stations at $22 million to $28 million annually, about 10 times more than the state has been spending in recent years. If funded by surcharges on boat licenses, the cost of a three-year license could jump by $35 or more.
"These are some ideas that need to be vetted further," said Luke Skinner, supervisor of the DNR's invasive species program.
The study presents seven scenarios for greater restrictions that range from $10 million per year (inspecting only boats leaving containment zones around key zebra-mussel-infested waters) to $610 million annually (inspecting all boats entering and leaving all 3,600 public and private boat accesses in the state).
The mussels fasten themselves to hard surfaces such as boats, docks, motors and trailers, and in their larval stage are too small to be seen in bilge water and bait buckets. Some people are urging mandatory inspections and boat washing to keep the mussels from being transported carelessly or inadvertently by boaters who move from lake to lake.
Red lakes and blue lakes
One approach described in the study is a red lake/blue lake system, in which infested waters would be classified as red, and non-infested lakes would be called blue.
Boats in red lakes would be required to have a red tag, and would need to be inspected and possibly decontaminated in order to get a blue tag to move to a clean lake. Boats in blue lakes with blue tags would receive a red tag if they launched in infested waters, but otherwise could move freely from blue lake to blue lake without inspections.
The inspection stations themselves could be at strategic lakes, or in centralized locations that might serve a cluster of nearby lakes.
Skinner said the study provides a good "snapshot" of options, but not necessarily a direction that the state will follow.
Zebra mussels have been confirmed in 29 lakes and nine rivers in the state, he said, and are suspected in about 30 additional connected lakes.
As the mussels have spread, lakeshore owners and lake advocates have urged the DNR to do more to contain them.
Last year, the Legislature devoted $5.6 million from state lottery proceeds as a one-time expenditure for the DNR to purchase more boat-washing stations and beef up inspections at heavily trafficked lakes that are already infested, such as Lake Minnetonka.
Skinner said that establishing a stricter inspection system for boats that leave or enter infested waters would require legislation and permanent funding to enforce.
"All of these ideas would take new laws," he said. "You'd have to have new authority to require mandatory inspections."
Ramping up for summer
Eric Evenson, administrator of the Minnehaha Creek Watershed District, said the state needs to do more work on estimating the true costs of zebra mussels before it moves toward higher fees or mandatory inspections.
No one has determined how zebra mussels in a Minnesota lake might affect property values, he said, or what they could mean for a resort.
"Without knowing what the real costs and economic impact of this are going to be," Evenson said, "it's going to be really hard for the state to know what direction to take."
With one-time appropriations this summer, Skinner said the DNR will hire 146 additional inspectors, focus inspections on high-use areas where mussels have been confirmed, and require training and permits for individuals and businesses hired to put boats, boat lifts and docks into lakes or rivers.
Sustaining those programs will require a long-term source of funding, according to a separate DNR report delivered to the Legislature in January. Boaters currently pay a $5 surcharge on their three-year license fees that goes into an invasive species fund. The January report estimates that surcharge may need to increase to $30 to $43 a year, depending on boat size.
To find the reports, go to www.dnr .state.mn.us/invasives/index_aquatic.html.
Tom Meersman • 612-673-7388