Specifications include, but are not limited to:. EXISTING FACILITY: a.) Cross Over – The existing aerial crossing over Copper Creek is located at (41.176399°, -95.997024°), it is a 90-inch steel pipe, approximately 50-feet of it is exposed. The current crossing is submerged during floods and is subject to backflow and damage from debris. There are signs of damage on the pipe due to debris collisions. b.) Interceptor Pipe – The existing interceptor pipe is 3,000 ft long and was built within the levee prism, underneath the Keystone Trail. The existing interceptor located below the surface is a reinforced concrete pipe (RCP) that was designed with a 3-inch sacrificial concrete layer. Closed-circuit television (CCTV) investigations showed significant signs of deterioration and corrosion. The interceptor is close to reaching its service life expectancy of 50 years (built in 1972) and its current condition is a reflection of its age. REPAIR TO FACILITY: a.) Cross Over – The existing pedestrian bridge over the aerial pipe would be temporarily removed during construction in order to remove the existing aerial pipe. The new crossing of Copper Creek will be relocated approximately 200 ft upstream from the current crossing at (41.176685°, -95.996271°). The approach selected at the new Copper Creek Crossing is to construct a multi-barrel, inverted siphon in addition to relocating the interceptor outside of the levee. b.) Interceptor Pipe – Applicant proposes to relocate the interceptor to a location outside of the levee prism to protect it from levee failure. It will be approximately 3,350 LF and 75 ft adjacent/parallel to the levee/existing interceptor location. The existing section of the interceptor would be filled with flowable fill and no longer be in use. The applicant plans on bypass pumping for approximately 18 days. Depth of excavation is approximately 14 ft deep, 3,350 ft long, and 50 ft wide for the interceptor. To access the areas of work with the necessary construction equipment and vehicles, the concrete and asphalt paths may be utilized as well as the parking lot area nearest to the levees. The parking lot may also serve as an area to stage and store materials and equipment during construction. Areas that are disturbed by the constructed improvements will be restored to their existing conditions. It is anticipated that adjacent agricultural land may incur some crop damage and/or delays in farming from the construction activities and will request compensation in advance.
