Tonight, one of the last items on the City Council’s agenda was Savage Lake water quality. Before the meeting, Joel Hansen dropped a packet off at many Savage Lake homes describing the history of the lake, some of the problems, and the options available to the city and residents. One of the suggested remedies for the lake has been rain water gardens. Residents were asked to bring a signed copy of an approval form if there is interest in installing rain water gardens on Savage Lake yards.
Joel summarized the recommendations of the city, the Watershed District, and residents. The Watershed District’s measurements stated that the “100 year flood” level and their estimation of the current lake level would not allow for an further change in the lake level. The DNR has allowed for chemical irradiation of up to 5 acres of water lilies on the west Savage Lake. There is some discussion still left regarding the weir design and height.
Joel discussed recommendations for a different street sweeping system to pick up more of the “fine particulate” material from the streets. That involves a $200k purchase of equipment, which members of the council (especially the Mayor) balked at. They discussed cost sharing the equipment with another community.
I asked that the city look into containing the runoff from the freeway into the east side of the lake. Joel admitted he hadn’t included that in the summary, but he was working on that issue. In retrospect, I realized that the freeway runoff should be the responsibility of the state, particularly DOT. I offered to obtain pictures of the sediment traps used at the Shakopee Arboretum to provide to Joel as a design possibility.
Joel will call for a neighborhood meeting to discuss and describe the remedies for the lake. October 20th, at 7PM is the proposed meeting date.
From the city's meeting notes:
SAVAGE LAKE WATER QUALITY ISSUES
The City Administrator reviewed his October 3, 2008 report on the Savage Lake water quality action plan which was directed last summer after a neighborhood meeting held by the Watershed and City staff.
The Administrator reported that the first action plan task dealt with lake level. The Administrator indicated that research has been done and some conflicting information found, however, it appears that the lake level has always been very close to the current outlet level of 895.1. The Administrator noted that the Watershed has conducted an elevation survey of nine homes around East and West Savage Lakes that appeared to have the lowest elevations as compared to the lake level. The results of this analysis is that the 100-year flood elevation is only .2 feet above the low entry elevation of the shop garage at 334 Little Canada Road. Based upon Watershed rules, they cannot support any increase in the normal elevation as that would increase the 100-year flood elevation. Given the elevation of the lowest structures, that would put them in the 100-year flood plain. The Administrator reported that one possible modification was suggested by Little Canada resident Tom Wenzel, a senior water resource engineer with the MN Board of Water and Soil Resources. He suggested modifications to the hydraulics of the new structure to better match those of the former culvert. This would slow down the removal of flood waters, thus resulting in more flood detention, increased residence time, periodic increases in flood elevations, and hopefully have some impact on how much the lake drops below the current elevation as the summer progresses. The Administrator reported that the Watershed will be evaluating this option.
The second task was to determine the feasibility of eradicating lily pads. The Administrator reported that he has met with Mr. Neil Vanderbosch, Aquatic Plant Management Specialist with the DNR, who indicated that a full eradication will not happen. The Administrator indicated that Mr. Vanderbosch will be revising the plan he previously prepared to indicate the level of eradication that will be acceptable. He has indicated that a maximum eradication of 5 acres is acceptable for large bodies of water, and has suggested that 3.5 acres may be the most that will be approved for West Savage Lake. The Administrator reported that it is an expensive undertaking to contract for eradication. The Administrator suggested an economical option would be for the City pay the cost of the chemical if there are residents on the lake willing to apply it.
Blesener asked for clarification on the outlet weir (normal level). The City Administrator noted the correspondence from the Watershed indicating that the top of the weir is 895.4, which was raised from 895.1 in 2006 to compensate for the tip in the outlet pipe. The Administrator noted the need for the DNR to modify their information to correspond with the 895.4 level. Blesener pointed out that the 100-year flood elevation is only two to three inches below the Smith’s garage floor elevation.
The Administrator reviewed task 3 for dredging the wetland at Jackson and Demont. The City Engineer will have plans and specs ready for this work by the end of the month to be completed over the winter. He will include alternates for the sediment plumes in areas of Savage Lake noting that access to these areas will be difficult.
Task 4 relative to evaluation/installation of storm water improvements. The Administrator noted that the installation of rain water gardens in the Savage Lake drainage area is the most reasonable option. Surveys were recently mailed to property owners in the drainage area to determine the level of interest. Survey information is due by October 15th. The Administrator indicated that the plan would be to have these rain water gardens installed next summer.
Task 5 calls for the evaluation of a street sweeper purchase. The Administrator reviewed the two types of sweepers, noting that the regenerative air sweeper is favored by the Watershed as it picks up the fine particulates which carry the most contamination. The cost of a regular sweeper is estimated at $140,000 versus $200,000 for the regenerative air sweeper. The Administrator indicated that the Watershed has been approached relative to funding a portion of this cost as a demonstration project. The Administrator also indicated that the cost of this equipment could be included in the City’s Capital Improvement Budget or funded with LGA dollars depending on the level of future LGA funds. Blesener suggested that another option would be a joint purchase with another city, and suggested that City staff explore this option. The City Administrator indicated that staff is currently discussing a shared sweeper with neighboring cities. The City Administrator indicated that should a sweeper be purchased, the goal would be to hire a retired individual to operate the sweeper on an as-needed basis. With the purchase of a sweeper, the City’s streets could be swept more frequently, thus improving water quality, appearance, etc.
Task 6 calls for the evaluation of pre-wetted salt spreading. The City Administrator indicated that this task is still being evaluated.
Tom Day, Lakeshore Avenue resident, stated that he appreciates the work that the City is doing with regard to Savage Lake water quality. He indicated that there are two additional issues that need study. The first is the freeway run-off coming to West Savage Lake and the fact that the drainage pipe is full. The City Administrator indicated that staff would check on this issue. The second issue is the drainage from the north side, and Day suggested the installation of sediment traps. Day indicated that he would obtain some pictures of these traps.
The City Administrator suggested that the next step would be to call for a neighborhood meeting to review study progress with the neighborhood.
Mr. Blesener introduced the following resolution and moved its adoption:
RESOLUTION NO. 2008-10-250 – SCHEDULING A NEIGHBORHOOD MEETING FOR MONDAY, OCTOBER 20, 2008 AT 7:00 P.M. TO REVIEW THE SAVAGE LAKE ACTION PLAN UPDATE
The foregoing resolution was duly seconded by Montour.
Nays (0). Resolution declared adopted.