Admin Order 58-12-14 - Laserfiche WebLink

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Lane County Board of Commissioners April 27, 2010 Page 3 The District maintains a system of agricultural drainage ditches that extend from the Amazon Channel in west Eugene to the City of Monroe. The District's boundary and its ditch system overlap the City of Eugene's Urban Growth Boundary between Beltline Road and Beacon Drive. Essentially, the District eventually receives all of the city's storm water from that area. The District's A -1 Channel and its F Channel are located in that area. The District's system was developed over 40 years ago to partiall drain a c , ultural lands in the area between Eugene and the City of Monroe. The District operates and maintains its system pursuant to numerous easements across private property. The District's system was developed to serve flooded agricultural lands —it was not developed to receive water discharges from the impervious surfaces of urban lands and urban uses. The District's system was developed to drain flood waters from agricultural lands and was engineered to limit inundation of those lands to several days in duration —it was not engineered to immediately remove all storm water from those agricultural lands. The District's system has no additional capacity to handle storm water fiom impervious surfaces of urban land that exceed historical pre - development flow rates. The impact of discharging storm water from urban lands into the District's system is exacerbated by the development of residential subdivisions over lands that contain the ditches. In the case of the southern end of the two channels between Beltline Road and Beacon Drive, the District is prevented from performing any function on them in areas of residential development. The construction of fences and other residential development serves as a barrier to District efforts to maintain the channels for the five flow of flood and irrigation waters. The Lynnbrook 11 subdivision is a perfect example of such a situation. Even though C,C &Rs were recorded with the subdivision, many property owners have not provided any maintenance effort and, in some cases, have actually placed structures and vegetation, including trees, within the ditches. Back yard fences prevent the District from any access to the ditches for maintenance purposes. Out of concern about encroaching urban development from both the cities of Eugene and Junction City, the District retained the services of EGR & Associates, Inc. ( "EGR "), to conduct a capacity study of that portion of the Flat Creek basin that contains the F, F -2 and F -2 -a Channels (the area closest to Eugene on the south, Junction City on the north and including the site of the planned State of Oregon hospital and corrections facilities). EGR concluded that the District's system of flood control ditches is at capacity during significant rainfall events. It also concluded that high water tables throughout the area limited the amount of storm water absorbed by soil. Concluding that the District's ditch system has no additional capacity for post - development storm water discharges from newly - developed urban land, EGR recommended to the District that it promulgate policies to apply to requests from urban development for the discharge of post - development flow rates of storm water into the District's system. Those policies were adopted by the District's Board of Directors and are as follows: 1. For properties within the Flat Creek basin, post - developed storm water flow rates shall be regulated for the 2 -year through 50-