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Drainage on this portion of the street will be handled by a conventional storm <br />sewer system. Surface water treatment ponds would be required on the <br />recreational shoreline Tots where the ditches currently discharge. Because of the <br />flat grades, there may be a number of vane grates installed in the curb to collect <br />runoff. Infiltration will be used to the maximum extent allowed. However, high <br />groundwater may preclude the use of infiltration in some areas. <br />2. Middle Section Street, Trail and Drainage Improvements <br />Because of the wetlands within this middle section of the roadway, we <br />recommend a 28 -foot wide rural section road be built with 2 -foot wide gravel <br />shoulders. The grade of the road should be raised to 2 feet above the 100 -year <br />flood for separation from the lake surface. Some wetland filling will be necessary <br />to accomplish this design. <br />With the thick peat deposits near the channel crossing, special construction <br />techniques are required to build this portion of the road. A thick section of fill <br />would be placed over the peat. The peat will then be given time to consolidate <br />and settle. During the time it is consolidating, a temporary gravel road can be <br />placed on the fill. The fill is monitored, to check the consolidation rate and <br />amount. When it appears the majority of the settlement is complete, the <br />permanent street section is built. This process can take as long as a year or <br />more to complete. <br />The culvert in the channel would be replaced. The elevation and size of the pipe <br />would remain the same in order not to change historic lake water levels. <br />If a trail is desired along this section of roadway, we recommend placing it on <br />the roadway as a 4 -foot wide shoulder. A separate trail will involve additional <br />wetland mitigation and earthwork. A long bridge across the wetlands and <br />channel could also be built, however the cost would be significantly higher than <br />widening the shoulder of the street. <br />Drainage on this portion of the street will be handled by roadside ditches. <br />Infiltration will be used to the maximum extent allowed. However, high <br />groundwater may preclude the use of infiltration in some areas. <br />Page 6 13849.005 <br />