HomeMy WebLinkAboutMiller Plant Plan
Miller’s Bay Aquatic Plant Management Background Native and exotic submerged aquatic plants in Miller’s Bay, adjacent to Menominee Park reached nuisance levels in 2007 and required action
to restore navigation to Lake Winnebago from the sailboat mooring area and the boat landing located at the south end of the bay. The action that was taken was chemical treatments of
three areas totaling 21.31 acres on June 10, 26 and July 30, 2008 with a total cost of $20,577.60. These treatments resulted in the immediate relief to navigation. While the chemical
treatment was effective there had not been a thorough study of the bay’s plant life, and there remained no management plan for the bay. The chemical treatments of the Miller’s Bay were
paid for partially by an Aquatic Invasive Species grant from the Department of Natural Resources. Part of the grant required that the city have a plant survey conducted of the bay and
a management plan drafted. The firm Onterra was contracted to do the work. Their plant survey found that invasive species were not the main nuisance plants, the native species Coontail
was. Onterra plant survey concluded that the plant life in Miller’s Bay is indicative of a disturbed system. Miller’s Bay’s disturbance is a result of heavy human use. It is completely
surrounded by lawn, receives heavy boat traffic and urban runoff. Mechanical Harvesting vs. Chemical Treatment Onterra’s study evaluated the management options for the aquatic plant
community. They listed four management options: 1) do nothing, 2) dredging, 3) chemical treatment, and 4) mechanical harvest. Options one and two were quickly discounted. The other options
were broken down by cost and by other pros and cons. Onterra recommended that 16 acres be maintained for navigation and additional areas be cleared to improve fish habitat and fishing
opportunities. To annually maintain 16 acres for navigation the projected cost was $14,240 using a less expensive herbicide than was used in the 2008. Three annual cuttings with a mechanical
harvester would total $8,625. The cost of harvesting includes the cost of labor, maintenance, other expenses and the cost of the harvester after a possible 50% match through a DNR grant.
New harvesters are around $100,000. In July 2009 five were available from Aquarius Systems, North Prairie, WI ranging from $13,500 to $25,000. Purchasing a used harvester would significantly
reduce the startup costs. Further reducing the costs to the city would be contracting the harvester to nearby communities, groups and individuals. There are currently 9 permit holders
for nuisance plant control in the area that may benefit from mechanical harvesting.
Mechanical harvesting has many benefits over chemical treatment. One that cannot be denied is public perception. Having photos of people in chemical suits spreading herbicide into the
water where hundreds of people fish and swim does not seem healthy, or sustainable. Second, harvesting can be done as needed. Much like a lawn, when growth becomes rank the plants are
harvested. Third, the plants are cut in the water and then removed to be composted, leaving few plants to decay in the water to and feed algae blooms. Recommendations After weighing
the costs and benefits of harvesting vs. chemical treatment Onterra recommended the purchasing of a harvester. While these capital investments may seem high during the current economic
climate, in the 2002 Oshkosh citizens survey Oshkosh residents ranked being on the water, and parks as the number one and two as the most desirable features of Oshkosh. Also Parks/Playground/Boat
launching was number three on the list for capital improvements for high priorities in the Comprehensive Management Plan. Clearly the citizens of Oshkosh want their parks and boat landings
maintained. The Water Working Group recommends that the Oshkosh Sustainability Board advise the Council seek the purchase of an aquatic plant harvester. We further recommend that a comprehensive
plan be developed for the wildlife, fish, and water quality of Miller’s Bay and Menominee Park. Next Steps • Draft sent out with January agenda as background for Bill's presentation
• Following January meeting, Water Group meets to finalize reports • Reports presented for approval at February SAB meeting