Agenda - Public Works Committee - 10/20/2015

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5.01: Consider Request to Reconstruct Stormwater Treatment Improvements at Sunfish Lake City Engineer Westby reviewed the staff report and noted the property owners are present at the meeting. He explained the original purpose of the swale was to keep the solid waste from entering the wetland. The intent of the easement was to allow the City to maintain the swale as needed over time. He noted the swale has not needed maintenance by the City since it was put in. He explained one of the more cost effective resolutions is to construct a settling basin with overflow that would allow the sediment to settle over time. He said he is not sure that this will be a permanent solution but it would reduce some of the water in the swale for the long term. The cost will be between $15,000 and $45,000. The price difference is dependent on the size of the basin, wetland mitigation credits, and on the turf restoration method. He pointed out this is a system that was constructed and is operating as intended. The property owners have requested the City complete the work of constructing a settling basin, and pay for the construction, since the swale cannot be maintained by the property owner and their property is compromised. He mentioned that the basin may need occasional cleaning over the next 50 years; however, it likely wouldn't need it more than a few times. Chairperson Riley introduced property owners, Jay and Suzanne Bergevin, 14520 Sunfish Lake Drive. Mr. Bergevin explained when they purchased the home, it was described as having a drainage ditch. It worked to drain water and functioned as a ditch for many years. He said their biggest concern is that there is a change. The drainage worked well for 9 or 10 years. In the last 5 years or so, they have seen it change from a drainage ditch to a pond that is 2 to 3 feet deep. He explained he cannot get to the other side of it to maintain the area around it. He cannot take care of the area that is under water, as wetland vegetation is now growing. He stated the water has not receded over the last 2 years. It has gotten high enough to reach the berm. He said he could not understand how the stormwater could have been vented through his property, and still reach the top of the berm. He noted it doesn't sound like much sediment has been caught at all. He concluded that he thought they have been patient, asking about this for 3 years, and watching it grow to where about 40% of their yard is now unusable. Mrs. Bergevin stated the definition of drainage is that it is not supposed to settle. She noted this was called a drainage easement on the papers, originally, and not a swale as it is called now. The ponding water is muddy, allowing mosquitoes to breed, and now there are fish in the pond. She said it is not a healthy environment. Mr. Bergevin stated this has reduced the quality of life for them. He said they are unable to enjoy backyard events with friends and neighbors. He explained the high water level of the lake in 1983 to 1988 was 858 or 859. He stated it is 864 now. This is impacting beyond the drainage easement. The design of the easement and drainage pond was implemented in the early 1990s. He said they are requesting the City to restore it to what it was. Mrs. Bergevin stated the drainage ditch is clearly not working as it was intended. She said there was a large black pipe pouring water into the lake at one point, but there is no official record of Public Works Committee / September 15, 2015 Page 2 of 9