5.1. SR 09-07-2010 - Laserfiche WebLink

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REQUEST FOR ACTION TO ITEM NUMBER Ci Council 5.1. AGENDA SECTION MEETING DATE PREPARED BY Administration September 7, 2010 Nicola Blake-Bradley, Environmental Technician ITEM DESCRIPTION REVIEWED By Lake Orono Drawdown to Reduce Curly Leaf Pondweed - Rebecca Haug, Environmental Public Hearing Administrator REVIEWED BY Lori ohnson, Ci Administrator ACTION REQUESTED Staff requests approval to move ahead with submitting a permit application to the Department of Natural Resources (DNR) to temporarily draw down Lake Orono by approximately 5' for control of the invasive aquatic plant Curly Leaf Pondweed as a result of the petition submitted by the Lake Orono Improvement Association. BACKGROUND/DISCUSSION Curly Leaf Pondweed (CLP) is an invasive plant which reproduces both sexually by seed (called turions) and asexually by plant division. The plant forms large mats at the surface of the water in shallow areas (up to 5', normally) which prohibits recreational vehicle movement. When CLP plants are broken apart (often by boat motors), each subsequent piece is able to produce a whole new plant. This, coupled with turion production, allows the invasive plant to exponentially expand and overtake beneficial native plants. When the invasive weed mats die back, their decomposition takes all the oxygen out of the water creating a hazardous environment for all aquatic life forms in the vicinity. In 2003, Lake Orono was drawn down, using a maintenance permit for the dam, for the same purpose with moderate success. Since then, volunteers have been hand pulling the CLP each year under an annual permit which the City has obtained. The CLP has continued to increase its area and distribution each year. The Lake Orono Improvement Association believes that a drawdown will set back the CLP to a level which may be controlled by hand once again. The DNR will determine when the lake may be drawn down and the length of time to be drawn down. The drawdown would be temporary with a slow draw down for turtle and other aquatic organism adjustments. Two weeks of freezing weather is required to ensure maximum turion control. After that period, the Lake would be allowed to return to an ordinary high water level. FINANCIAL IMPACT Staff intends to request the drawdown through the use of the maintenance permit once again to avoid the necessity for a public waters work permit. If a public waters work permit is not required by the DNR for this project, the only costs will have been associated with the public hearing notice and mailing. Otherwise, if a public waters work permit is required, the permit may cost $1,000. C:\Users\jmiller\AppData\Local\Microsoft\Windows\Temporary Internet Files\OLKE8DB\Action Requested - drawdown.doc