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2. City Pol./Eurasian Milfoil 690 City Center Drive, PO Box /47 FROM: Chanhassen, Minnesota 55317 Phone 612.937.1900 DATE: General Fax 612.937.5739 Engineering Fax 612.937.9152 SUBJ: P"blic Saftty hy 612.934.2524 \féb ll'li'Il',á.challhassmmn,lIs CITY OF CHANHASSEN .' :) ~.' - MEMORANDUM TO: Don Ashworth, City Manager Phillip Elkin, Water Resources Coordinator June 24,1998 City Policy for Control of Eurasian Water Milfoil (EWM) Update This is an unresolved issue fTom last year. Basically, the City Council needs to decide whether the City should continue to contribute to the efforts of the Lake Minnewashta Preservation Society. This group has organized management of milfoil on the lake through the use of the herbicide 2-4D. The City does not get involved in treating any other lake for the control of eurasian water milfoil, however, Lake Minnewashta is unique in that it has large shallow areas of water which become clogged with milfoil and make reasonable use of the lake difficult. Harvester information Last year one of the options discussed was using a harvester to collect milfoil in all city lakes and avoid the use of chemicals. I have received the following information fTom the Lake Minnetonka Conservation District which has an extensive harvesting program for Lake Minnetonka. They employ a staff of 10 people. A two person crew for each of their four harvesters, a full time mechanic and a full time truck driver. Cost of a new harvester is approximately $100,000. They have found that to be cost effective, they need to operate at least four harvesters. This is because the harvesters move very slow and it takes 2-3 harvesters to fill one truck load. I believe this practice would be too costly and there are not enough public areas infested by milfoil for the City to justify the cost. Recommendation While milfoil has infested several lakes within the City, Lake Minnewashta is the only lake where milfoil is found in large areas in waters away fTom the shoreline. At this time, using 2-4d is the most cost effective way to manage milfoil on Lake The City of Chanhass",. A growing community with dean lakes, quality schools, a rhO/ming tÚJwntown, thriving businesses, and benutiftl parks. A great place to live, work, and play. Mr. Don Ashworth June 24, 1998 Page 2 Minnewashta. I would recommend continuing to match the MnDNR's contribution until a reasonable alternative is found. This contribution should be conditional on the group providing the City with updated maps of areas treated each year, and that lakeshore owners are informed of treatment one week in advance. Background - 8/20/97 The following list documents the city expenditures on milfoil since the program began in 1990. From 1990 to 1994, all calls regarding milfoil were directed to Park and Recreation and Public Safety. These departments referred the calls to the Minnesota Department of Natural Resources who were in charge of eradication efforts. Each lake had its own allocation of state money to spend on herbicide treatment supervised by the DNR. Once the state fund was spent, the DNR would then bill the City for any additional dollars spent on herbicide treatment. In 1995, the DNR changed it's policy and allowed cities, Lake Associations. watershed districts or any interested group decide how this money would be used for milfoil management. That year, Chanhassen allocated a portion of the Storm Water Utility to establish a Lake Management Fund (420). This fund would be used to produce lake management plans, water quality monitoring and other issues associated with lakes including milfoil management. Since the establishment of this, Lake Minnewashta has been the only City lake to receive money fTom the City matching the state money. In addition to money spent on milfoil treatment, I have also included the cost of Surface Water Management Projects directly related to the recreational lake's watershed, similar to the projects proposed for Lake Minnewashta. Some of these projects have been completed by the street department staff and many are still in progress. City Funds Spent on Milfoil Per Year 1990 1991 1992 1993 1994 1995 $2,500 $5,000 $5,000 $5,000 $10,000 Lake Minnewashta 1996 Lake Minnewashta $2,529.00 Fnnds Re-directed into Lake management fund $2,384.00 " Mr. Don Ashworth June 24, 1998 Page 3 SWMP Projects Summary LAKE PROJECT COST Lotus Yuma Drive * $30,207 Lotus Ravine * $21,911 Fox Path $2,570 Frontier Trail * $19,459 Chaparral Pond ** Chanhassen Pond Park outlet * $457 Lake Management Plan $9,430 $84,034 Minnewashta Lake Management Plan $9,430 1997 W.Q Projects *** $129,870 est. MiIfoil Match $4,913 $144,213 Christmas Curry Farms Pond ** $17,765 Pleasant View Road Ravine $41,117 Lake Management Plan $3,500 Holly Lane *** $82,000 $84,382 Susan Lake Management Plan *** $3,500 Powers Blvd. Wetland Restoration * $32,000 $35,500 Riley Lake Riley Wetland *** $31,000 Lake Management Plan $9,430 $40,430 Ann Lake Management Plan *** $2,500 Lucy Lake Management Plan *** $2,500 Mr. Don Ashworth June 24, 1998 Page 4 * ** *** Design Cost - Construction Completed by Street Dept. Internal Design - Construction by Street Dept. Still in Progress cost-to-date For the past three years the City ofChanhassen has contributed funds to the Lake Minnewashta Preservation Association for the purpose of controlling Eurasian Water Milfoil (EWM). The City' Surface Water Management Utility matched funds provided by the Minnesota Department of Natural Resources. This year, because the City was concentrating its efforts on water quality projects for Lake Minnewashta, I decided not to contribute to the Lake Minnewashta EWM program because of the cost of these projects, Representatives ttom this association are not pleased with this decision and fear losing City contributions in the future. In addition to Lake Minnewashta, representatives ÍÌ"om Lotus Lake, Christmas Lake and Lake Riley have approached the City asking for assistance in their EWM treatment efforts. Currently, the City has no formal policy on contributing to lake association efforts to treat EWM. The only reference I can find to this practice is the attached memo to council dated June 24, 1994. The memo references a EWM fund, which is now the Lake Management portion of the City budget. This money ÍÌ"om the Surface Water Management Plan is targeted for informational material for residents, lake management plans, and water quality testing. I have listed several concerns about continuing to operate in this manner: · The City drafted lake management plans for all of the lakes affected by EWM. None of the support suggested by these plans are being used. · As the DNR's contribution declines, lake associations will look to the City to make up the difference. · The City does not contribute to other homeowners associations for control of exotic species. · This policy is contradictory to recent efforts by the City to prevent the use of herbicide in other wetlands. · Attempts to treat EWM in this manner are short term actions, that will use as much money that is thrown at it. · Constant use of herbicide kills native plants and does not give native plants a chance to compete with EWM. · Continued use of2-4D may affect the long term quality oflake water and its ecosystem. MnDNR The Minnesota Department of Natural Resources is the governing agency for any activities below the ordinary high watermark (OHW) for waterbodies of 10 acres or more. They have conducted , " Mr. Don Ashworth June 24, 1998 Page 5 public education programs and lake monitoring to raise awareness and prevent the spread of the weed. Surveys are conducted annually to find lakes infected with EWM. Once a lake is found to have EWM, the DNR conducts its own eradication efforts by spraying infested areas with 2-4D. The DNR will continue this effort until EWM has been identified in 10% of the lake's littoral zone. At this point, the DNR has determined that the plant cannot be eradicated and will stop chemical treatment to allow the weed to run its course. A portion of each boating license sold is put into a fund for EWM management. This money is set aside for lakes infested with EWM and divided to each lake depending on size. It is this money that the lake associations are using for EWM treatment. ð; Status ofEWM in Chanhassen Lakes Lake Minnewashta The Lake Minnewashta Preservation Association has been active in raising close to $20,000 annually for the past few years to conduct lake-wide applications of2-4D. Lotus Lake EWM is a problem along the shore line to depths of approximately 4 feet, but because water clarity of the lake is so poor, it does not grow to the surface in deeper waters. A lake association has been inactive until last year, when they were approached by a consultant who offered to develop a milfoil plan for the lake. Since then, the group has been organizing efforts to combine individual property owner's treatments. Because milfoil is not a problem in areas eligible for DNR funding (see attachment), the only areas where DNR funds could be used are on public park property. Chemical treatment ofEWM is not endorsed or permitted by City Parks and Recreation staff. Lake Riley EWM has been a problem in the past, but in the last two years the lake has not been clear enough for EWM to be a nuisance. Lake Ann The DNR detected EWM near the public access in 1995 and has been attempting to eradicate the weed with applications of2-4D each year since. :",;J Mr. Don Ashworth June 24, 1998 Page 6 J Christmas Lake Same status as Lake Ann. The lake has areas ofEWM detected in 1995, which the DNR is still treating with hopes of eradication. Lake Lucy EWM has not been detected. Lake Susan EWM has not been detected. Rice Marsh Lake EWM has not been detected Recommendations Because there is no evidence that treating with 2-4D provides long term eradication of the weed, I would recommend that the City discontinue providing money for this short term treatment program. This action does not prevent the individuallakeshore homeowner ÍÌ"om treating lake areas adjacent to their property, nor does it prevent associations ÍÌ"om using MnDNR funds for treatment. I have included some options on how the City Council can act on this issue. Continue to match DNR funds on eligible lakes · Continue to cooperate with existing programs · Identify high use areas to be treated · Require updated maps of areas treated each year · Conduct extensive plant surveys every other year to monitor affects on native species Discontinue to fund herbicide treatments · Fund plant inventories and water quality studies · Allow nature to take its course and learn to compete with EWM Set a limit on money to be spent by each lake for EWM treatment · All lakes given a set dollar figure for EWM management · Conduct extensive plant surveys every other year to monitor affects on native species · Require updated maps of areas treated each year