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wetland has a ditched outlet that has substantially lowered the hydrology of the basin. The ditch <br />is 12 -feet wide and approximately 4 -feet deep. Prior to the ditching the wetland was likely a <br />shallow marsh. Ditching has caused this basin to be reduced in size and also has resulted in the <br />hydrology being almost completely removed. The wetland could be restored with a berm 2.5 <br />feet high and a spillway 1.5 feet above the bottom of the ditch. The basin is in danger of <br />disappearing from lack of hydrology and invasive species. Boxelder, glossy and common <br />buckthorn, elder, American elm, Tartarian honeysuckle, and aspen are encroaching on the edge. <br />Community <br />Activity <br />Priority <br />Estimated Cost <br />Comments <br />LL-WI <br />Block ditch <br />Medium <br />$500.00 <br />Create berm and spillway to restore <br />outlet <br />hydrology <br />LL-WI <br />Remove <br />Medium <br />$500.00 <br />Could be in conjunction with upland <br />invasive veg. <br />clearing. <br />Community LL -W2 <br />Shallow Marsh/Wet Meadow <br />Qualitative Rank: High/Medium <br />Area: 0.3 acres <br />This basin is directly connected to the southern tip of the lake. A boardwalk crosses the wetland <br />near the lake edge. A high berm separates this wetland from a storm pond to the east. The <br />wetland vegetation is primarily cattails, with black willow, duckweed, and soft -stem bulrush. <br />Buckthorn and sandbar willow are present in noticeable amounts. Reed canary grass has become <br />more dominant in the southern portion of the wetland where sedimentation has occurred. This is <br />a highly visible wetland with the boardwalk and a grass walking path from businesses to the <br />south. <br />Historic sedimentation from parking lot located southwest of this wetland was observed. This <br />has resulted in a conversion to reed canary grass and reduced the hydrology of approximately <br />3,400 square feet of this basin. Restoration of this basin would involve removal of 1 — 2 feet of <br />accumulated sediment. Sediment traps at the discharge point of the parking lot would help to <br />reduce sedimentation in the basin. Catch basin at the end of the cul -de -sac has a low curb that <br />allows some drainage to be directed to W2 without treatment. Curb modifications or a berm <br />should be placed to insure flows enter the catch basin and ultimately reach the storm water <br />treatment pond. <br />City of Roseville 112 <br />Parks Natural Resource Management <br />