Description

LPV-09.1 - PS#1 (Bonnabel) Floodwall Tie ins & Floodwall/Gate at Boat Launch - Phase 1
Scour protection and minor earthwork.

This pump station is at the end of an interior drainage canal that approaches the lakefront levee at a significant angle to the shoreline. Because the pump station sits perpendicular to the canal centerline and a short distance landward from the lakeshore, the western end of the station is offset by several hundred feet from the hurricane protection levee alignment, and the east end setback, but less than the west side. At present a low levee and the embedded steel sheet pile (and I-Wall) connects the west end of the pump station's fronting protection to the lakefront hurricane protection levee. Both the levee and the embedded I-wall are legacy elements of the flood protection system pre-dating the LPVHPP, and do not meet current standards for strength, elevation and stability. East of the station a short section of tall I-wall provides a transition between the station and the adjacent levee. The extension of this I-wall above the supporting ground does not meet current standards and thus is also deficient. The plan to remedy these deficiencies calls for new levees and floodwalls on both sides of the pump station. Also the Bonnabel Blvd. vehicular gates and the concrete monoliths in which they are mounted, as well as the flanking concrete capped transitional I-walls are deficient in elevation.

LPV-09.2 - Pumping Stations #1 (Bonnabel), #2 (Suburban), #3 (Elmwood) and #4 (Duncan) Modifications, Fronting Protection, Positive Cutoff and Floodwall Tie-ins - Phase 2
Bring to 100-yr. level of protection. Contracts LPV-09.2, 10.2, 11.2 and 12.2 have been combined into 09.2

The floodwalls to the east and west of each Pump Station provide the connecting link between the floodside face of the station and the Lakefront hurricane protection levees. The floodwalls at PS #1 consist of several sections of uncapped steel sheetpile I-wall totaling roughly 87 linear feet, two sections of capped I-wall totaling 238 feet long, and two sections of concrete T-wall totaling 585 feet in length. The floodwalls at PS #2 consist of two sections of uncapped steel sheetpile I-wall totaling roughly 1036 linear feet in length.The floodwalls at PS #3 consist of two sections of uncapped steel sheetpile I-wall totaling roughly 384 linear feet in length. The floodwalls at PS #4 consist of several sections of uncapped steel sheetpile I-wall totaling roughly 200 linear feet, a 144 foot long section of uncapped I-wall, and three sections of concrete T-wall totaling 1660 feet in length. Also included is a single 22 foot wide vehicular gate. All of these features are deficient in elevation, and the steel and concrete I-wall sections have excessive "stickup" (extending out of the ground more than 6 feet). The global stability of embankments in which all of these features are founded is also less then required by USACE/IPET standards.

LPV-09a.2 - Pumping Station #1 (Bonnabel) Breakwater - Phase 2
Construct concrete breakwater to elevation 14 ft.

Located in Jefferson Parish, on the east side of Causeway bridge and at the end of the Bonnabel canal, breakwater protection consists of a concrete monolith atop concrete pilings, similar to those constructed at Pump Stations 2 and 3. Pile driving and most construction will be accomplished from barges and floating plant. The structure will extend approximately 850 feet with a top elevation of 14 feet. The breakwater will be constructed to protect the outfall channel and pump station from wave attack.