Levee Alternative 2 Sample Clauses

Levee Alternative 2. ‌ With Levee Alternative 2, approximately 10,085 feet of levee would be constructed on the south side of the Rush River, approximately 0.13 miles north of the city of Amenia. This alternative would provide flood protection to Amenia residents for a 100-year, 24-hour flood event, as shown in Appendix C Map C-9. Levee Alternative 2 would be constructed with a top elevation varying from 959–969 feet above MSL, a 10-foot top, and 4:1 side slopes. A 15-foot clear zone would be maintained on the interior of the levee. Trees would not be allowed on the levee or in the clear zone as tree roots can compromise the integrity of levees over time. A stormwater pond would be developed for Levee Alternative 2 to capture floodwaters and runoff from approximately 860 surface acres in the immediate vicinity of the levee precluded from draining directly to the river by levee construction. The stormwater pond for Levee Alternative 2 would cover an area 650 feet by 1,500 feet with a depth of 16 feet—8 feet for a permanent pool and 8 feet for bounce or live storage volume. The 8 feet of live storage assumes water levels in the stormwater pond would bounce 5 feet for a coincident 100-year event while allowing 3 feet of freeboard. This stormwater pond would be connected to a lift station. During normal rain events, gravity drainage would occur through gate well structures with sluice gates and the lift station would not be utilized. During a flood event, the gate well structures would be closed, and gravity flows would be diverted to the pond and pumped through the lift station to remove internal drainage. The lift station would be designed to pump at a peak capacity of 28 cfs, based on the capacity of existing culverts. The permanent pool of water would provide stormwater treatment to improve water quality and the larger volume would allow for additional material to construct the proposed levee. Approximately 42,715 CY of material would be needed to construct the embankment. This material would be collected on site through excavation of the stormwater pond. Significant cost items for construction for this alternative are related to the levee embankment, pond, and pump station, and xxxxxxxx structures totaling approximately $3,046,670. Other costs included in the estimate is mitigation for impacts to wetlands. For cost purposed, it was assumed that these wetlands were mitigated off site utilizing a federally approved mitigation bank. The estimated cost for mitigation is $68,000. ...