A state-commissioned study says a barrier of sound, bubbles and lights would be the most viable option to keep Asian carp from moving up the Mississippi River from downtown Minneapolis.
But the price of the barrier at Lock and Dam No. 1 would be high. The report says the estimated construction cost is $12 million, and could go as high as $19 million. And it would cost up to $250,000 a year to operate and maintain.
Asian carp have been found in Minnesota waters of the Mississippi River, including Lake Pepin and the Mississippi River near Winona, but there is no evidence yet that they are reproducing here.
The Department of Natural Resources says the study found an electric barrier would be most effective at turning back carp, but would be the riskiest to public safety and would cause corrosion of the lock. The study said federal authorities probably would reject it.
That led the DNR to recommend the sound-bubble-and-light barrier.