Facts about lake drawdowns

STATEMENT OF FACT REGARDING DRAWDOWN

Environmentally friendly ¹… no chemicals added to water, no machinery with potential of leaking oil/gas
Controls both Eurasion Water Milfoil and Curly Leaf Pondweed
Extremely Cost Effective ²… only cost is the permit $200 (paid by Association) and a few man-hours to open and close the dam bypass.

Fish³ There is no evidence of any fish kills. Rice Lake Association paid to restock per permit requirement after the 1998-99 drawdown; although most fishing is done by non-Association residents.

Fish migrate to areas of water with oxygen (i.e.: Elm Creek to the dam). The most severe recent winterkills came when we did not have a drawdown. Oxygen levels were not monitored lakewide during drawdown; furthermore, winter oxygen levels have not been recorded during non-drawdown conditions.

Easy to maintain results, no method is "one time only", all need to be repeated to have long term effects. Rerouting storm sewers and cleaning up Elm Creek would help eliminate nutrient loading.

Drawdown should be a every 3^rd to 4^th year event, dictated by natural fish kills the previous year. This will ultimately improve water quality, improve the fish community and prevent Eurasion Water Milfoil from taking over the lake.

Rice Lake is the largest of 7 lakes in Maple Grove, with the most City owned trail/land surrounding it.
Water clarity has improved since inception of drawdowns. Secchi disk readings prove this. *See report

Summer of 2001 was exceptionally clear water, until August. There was much more native vegetation which some people believe makes for lesser water quality, however, the natives are good for the water quality and fish community. Native weeds can be easily controlled by small applications of herbicide by individual homeowners, if needed..

Lake Quality Commission and the Minnesota DNR supports the drawdown initiative as an effective method to control exotic weeds. Lake Association and Tristan Bay Association members support the drawdown. There has been virtually no public objection to prior drawdowns.
Drawdown is an approved treatment as part of the Rice Lake Management Plan, which was adopted by the City.
Drawdown is also an opportunity to: Clean up lake bottom; dredge to improve water flow; reinforce shoreline , and maintain property values.
Shoreline restoration is made easy during the drawdown condition.

Regarding EWM experience with Lake Minnetonka, following the rapid spread of EWM over the lake property values around the lake dropped 10-15%. The City of Minnetonka, DNR and other agencies now spend tens of thousands of dollars each year just to control EWM. Rice Lake could be taken over by EWM as Fish Lake continues to infest Rice Lake with EWM fragments, however, Fish Lake has the DNR and Hennepin County to help fund control. If Rice Lake is taken over it will revert to a wetland use, with no recreational use, and property values will drop.

There are no proven negative side effects to drawdown.

Reference 1:

Drawdown is a NATURAL treatment. As Rice Lake is classified a State Class 3 wetlands, having less water in it occasionally would restore it to a more natural condition

Drawdown controls Eurasian Water Milfoil (which inhabits much of the lake now) and curly leaf pondweed, without killing the native species. Native species enhances the fish population by providing summer long habitat. Native weeds improve water quality by utilizing nutrients in the water for growth. Curly leaf pondweed contributes to water degradation by nutrient loading after spring die off, and inhibits the proliferation of native species. After curly leaf die off there is no fish habitat.

Reference 2:

Harvesting 54 acres, which is the maximum allowed by the DNR would cost from $275/acre ($14,645) to $339/acre ($18,136). Harvesting would not kill out (freeze out) the curly leaf seed bed, or effectively kill Eurasian Water Milfoil. Harvesting could actually spread EWM by creating fragments that will float over lake and up Elm Creek, then root in. Doing a drawdown and freezing the sediments eliminates curly leaf, the curly leaf seed bed and EWM at a cost of a few man-hours and a permit fee.

Herbicide treatment of 54 acres (maximum allowed) would be $9300. Rice Lake contracted Lake Restoration to do this work in 2001, however they only accomplished 19 acres. If ALL the curly leaf is not taken out it only keeps reseeding. Herbicide also will kill off the native species of vegetation that would provide fish habitat and reduce lake nutrients.

LQC/City matching funds previously spent treating algae blooms on area lakes for 1992 through 1996 totals $16,790. Cedar Island $3526, Rice Lake $6210 and Weaver $7053. Actual dollars spent was $33,580, City matched ½ of what lake associations spent. Eliminating curly leaf die offs should decrease algae blooms by decreasing nutrient loading.

Two sheets regarding costs for various control methods are included from our Lake Management Plan.

Reference 3.

Public usage of Rice Lake: Attached is Park Dept. memo regarding the "running of the crappies" this fall. Reestablishing native vegetation has benefited the fish population. There are several carry-on access points for small boats and canoes. Approximately 2.5 miles of park shoreline that is available for fishing from shore. The die off of masses of curly leaf create hazardous fish conditions, raising lake ammonia and sulfide gas levels in the water, which is harmful to fish community.

City of Maple Grove has supported many lake programs throughout the City, not only Rice Lake: All lakes have programs…they just don’t have to go to Council to get permission to do the work.

Weaver Lake has had an on-going curly leaf program for the past 3 years, receiving funding from Lake Improvement Program annually, also prior City funding for algae control.

Cedar Island Lake is monitored by the Shingle Creek Watershed district. Cedar Island has received past support for algae control in the lake, has received recent funding for assistance in weed control..

Fish Lake receives assistance from Hennepin Parks, Hennepin Conservation District (several aquascaping projects), and the Minnesota DNR for Eurasian Water Milfoil control, along with Lake Quality Commission support of programs.

Eagle Lake has an ongoing program with Minnesota DNR for purple loosestrife control and control of Eurasian Water Milfoil. Also, City assists to keep channel to Pike Lake open.

Pike Lake has program for improving sediment runoff overseen by City of Maple Grove for channel stabilization (approximately $650,000 from stormwater funds) in conjunction with the City of Plymouth, to control storm water runoff. Pike Lake also received support to reestablish wetlands filled in by Plymouth developers.