The state Natural Resources Board heard a lake management plan that they labeled as a success story for the Powell Marsh's Dead Pike Lake in the town of Manitowish Waters.
The plan focuses on the reduction of iron and phosphorus by stopping the loading of those components into the lake. Dead Pike Lake water quality has been damaged by iron floc, draining off an area where a failed experiment to bring in a goose population took place in the 1950's.Several residents of the lake said their property values are diminishing as the water quality gets worse from the iron.
The DNR's Dan Helsel says lower lake levels cause more iron and phosphorus to be in the lake...
"....we have a good idea about what influences a lake. We know that about 85 percent of the iron in the lake comes from the groundwater load, naturally occurring, and 65 percent of the phosphorus comes in through the groundwater. We recognize that lower lake levels cause increased groundwater input to the lake because there's not the hydraulic pressure there and if we raise the lake level the groundwater inputs decrease, so we can reduce those percentages..."
Environmental consultant Steve Apfelbaum says raising lake levels to it's historic range through a variety of means is the key action. He says the effort to attract geese lowered the lake levels and over time raised the iron and phosphorus levels.
"....if we're going to raise the outlet elevation of the outlet of the lake to raise the minimum elevation of the lake. We want everything to be reversable as part of a test. So how do we do that under existing permiting structure? That might need to be examined. We might need(NRB) support and thoughtful consideration....."
The plan also includes the addition of an inland wetland treatment system and construction of a clean water diversion from surface marsh surface water with lower iron and phosphorus concentrations and use of a passive lime-release in water habitat. Board members thanked the groups, including the Dead Pike Lake Association for a plan that they said could be a reclamation success story.