Agenda - Council - 01/11/2022 - Laserfiche WebLink

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Page 3 elementary school, located east of Nowthen Boulevard. A gravity line along Nowthen Boulevard was analyzed and found to be not feasible due to a large culvert located at Trott Brook. Although alternative means, such as an inverted siphon could be used to cross the creek via gravity, the capital costs and resulting potential maintenance costs, made this option not feasible. The interim service is recommended to include a lift station with a forcemain discharging to the manhole south of Trott Brook located along Nowthen Boulevard. We reviewed the gravity sewer along 170th Trail, Olivine Street and 168th Circle. Based upon both existing and future flows from the area, adequate capacity in the gravity main exists to allow for the Hunt Addition connection to occur. As reviewed previously, the existing lift station has capacity to accommodate the additional flows on a temporary basis. See Figure 6A for anticipated improvements. Hunt Addition and Makowsky Addition With the Hunt Addition and the Makowsky Addition developing simultaneously, a new lift station and forcemain would be required. This would be required if either a portion or all of the Makowski property develops. The lift station is assumed to be located near the southwest portion of the Makowski property, with the forcemain then installed along Variolite Street. The gravity sewer through the Makowsky Addition should be placed at an adequate depth to allow for the Hunt Addition to be served by the system. The main line should also be sized to account for areas north of Trott Brook, east of Nowthen Boulevard. The lift station should also be sized to accommodate the ultimate service area, which includes all areas north of Trott Brook. See Figures 6B and 6C for anticipated improvements. VI. WATERMAIN Based on the City's Comprehensive Plan, a trunk 12-inch watermain loop is proposed to extend along Nowthen Boulevard to 175th Avenue, along 175th Avenue to Variolite Street, and along Variolite Street. The watermains are a portion of the North Central Loop. Hunt Addition For the Hunt Addition, we assumed the trunk watermain would extend along Nowthen Boulevard to 175th Street and along 175th Street to the westerly edge of the Hunt Addition. The lateral watermains within the development will provide the interim looping of the system. See Figure 6A for anticipated improvements. Hunt Addition and Makowsky Addition If both properties develop, we assumed the watermain would be installed along Nowthen Boulevard from south of Trott Brook to 175th Avenue, along 175th Avenue to the westerly edge of the Hunt Addition. The trunk line along Variolite Street was installed as a portion of the recently completed roadway reconstruction project. The lateral watermains within the developments will provide the interim looping of the system. There will be a segment of watermain along 175th Avenue to be installed to complete the North Central Loop. This could be completed in conjunction with these improvements or completed Prepared by: Bolton & Menk, Inc. Trott Brook North Infrastructure Study — City of Ramsey