New Orleans $1-billion flood defense revised

the best value, and ECI provided us the opportunity to work with contractors and stakeholders to work out ways to optimize designs, manage costs and maintain schedule,” he says.

Bergeron notes that some industry people involved in the summit say it was nothing more than value engineering, and, to truly be an example of ECI, it should have occurred earlier and before GIC was actually under contract.

GIC broke ground on 6 August. By 3 December it had driven 250 of the 1,400, 30-in.-dia., 137-ft-long pump-station foundation support piles and 75 of the 116, 54-in.-dia., 140-ft-long king piles associated with the sheet pile for the combi-wall cofferdam. It also had excavated 300,000 cu yd of material for the pump station.

The largest cost saving developed during the summit, made at the suggestion of GIC, modifies the 20,000-cfs pump station to save $50 million to $100 million, according to Corps estimates. The savings come from lowering the discharge elevation of the pumps to raise each pump’s capacity to 1,880 cfs from 1,540 cfs. This move allows the number of pumps to be reduced to 11, from 13, and also helps cut the size of the building to house them.

The Corps’ original design called for placing the pumps at an elevation of plus-16 ft, which would surpass by 2 ft the predicted hydraulic elevation required by 2057 and fulfill a 50-year project life. “That takes into account sea-level rise increase, if the wetlands went away, and to ensure we would not have a faction that would have to be modified… down the road,” says Tim Connell, Corps project manager. The extra 2 ft was included to accommodate unknown variables, he says. The design change means the facility will lose that extra margin. Reducing the discharge elevation by 2 ft allows the Corp to keep the same engine and pumps, but those pumps will operate more efficiently, Connell says. Fewer pump bays means fewer foundation piles, fuel tanks, maintenance costs, etc., Podany adds.

HNTB Corp. recommended “modifying the pumping units to give them greater discharge capacity in order to reduce the number of pumps required,” says Bob Ivarson, practice director, water resources, for HNTB, technical lead on the pump-station design. “Our role in the project was the design of the pumping units [diesel-engine drives and auxiliaries, speed reducers and pumps], auxiliary equipment [overhead crane, emergency-power generation, fuel storage and trash racks and rakes] and superstructure and safe