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In the spring of 2006, these property owners contacted the City concerned about the effects of the 10/4/05 storm. We also were contacted by the property owner at 2241 S. Rosewood Lane to discuss flooding of their side yard after the same event. This event was intense and exceeded the design of the City's stonn sewer system. In an effort to find a solution for their concerns, the City tried to identify areas to constmct additional capacity into the City's storm sewer system upstream of this point. Due to limited right- of- way and topography, we did not feel there was a place to construct additional capacity on City controlled land. City staff met with the home owners and the Midland Hills Golf Course manager to discuss the possibility of a cooperative project that would expand the wetland onto the Golf Course, increasing the capacity of the wetland. The manager indicated that he would meet with their board to discuss the proposed solution. It is our understanding that they were not supportive. No solution has been agreed upon for this concern. City staff is open to partnering with the Golf Course, once they find a project that is acceptable to their board. . Impervious Coverage Variances Currently our City Code allows up to 30% imperviousness on single family lots. In the last 3 or 4 years we have been experiencing a significant increase in the number of variance requests from single family homeowners requesting more imperviousness than what is required by code. These variances are usually approved by the Planning Commission and Council. This has begun to concern staff. The reason for the concern centers on the fact that we are an aging suburb, with a confined regional treatment system designed assuming that all residential lots are 30% impervious. Staff understands that there are many lots over and under this percentage, but also understands that there is nothing we can do about existing situations. We can however control requested variances and their impacts to our system. Each individual variance may seem small, however, in aggregate they can compromise our regional ponding system causing existing ponds and pipes to exceed their capacity. As a result of this we feel very strongly that when a variance is applied for the property owner needs to address the hard surface increase on their site through rain gardens or other storm water best management practices to hold the rate of runoff at the 30% impervious rate or they need to convert a portion of their hard surface to pervious pavement/ pavers etc. resulting in no increase in hard surface. In addition to our capacity concerns, the City is being required by watershed districts and the MPCA to treat storm water at higher levels. They are requiring the City to reduce the volume of water entering the existing ponds, lakes, and wetlands that make up our regional storm water system. These requirements are increasing construction costs for our projects, as well as increasing the number of facilities that we are have to perform annual maintenance on. As a result, we cmmot continue to ignore the impacts of residential lots on the regional system City of Roseville 2006 Storm Water Annual Report Page 9 of 11