Posted on 19 November 2013
In August 2005, Hurricane Katrina caused extensive damage to the levees, floodwalls and other hurricane-protection works in the vicinity of the Inner Harbor Navigational Canal (IHNC), Gulf Intracoastal Waterway and Mississippi River-Gulf Outlet system. To restore the level of protection and provide the additional protection authorized by Congress after Hurricane Katrina, the U.S. Army Corps of Engineers is completing the construction of the Hurricane and Storm Damage Risk Reduction System (HSDRRS).
ARCADIS worked as part of a joint venture on components of the HSDRRS, to reduce risk to areas of New Orleans and surrounding parishes from future storm events.
The Gulf Intracoastal Waterway (GIWW) is a navigable inland waterway stretching more than 1,000 miles from Carrabelle, Florida to Brownsville, Texas. It was deemed a high-risk area post-Hurricane Katrina and received immediate recovery funds for the design of a hurricane storm damage risk-reduction system to withstand a 1% annual chance storm event. The West Closure Complex (WCC) consists of multiple structures across the entire GIWW.
A pump station, a large navigable sector gate and several floodwalls and levees systems were part of the design for a water structure capable of meeting the 1% annual storm event. This complex project required an aggressive project schedule and its sheer enormity, the need to maintain waterway functionality during construction, the potential social and economic impacts, and the public perception made it an enormous challenge.
ARCADIS designed a pump station as an integral part of the closure system that also consisted of a 225-foot navigable sector-gate structure and a smaller combi-wall. The pump station holds 11 massive pumps, each driven by a 5,400 horsepower diesel engine and weighing 70 tons, which is equivalent to viewing 11 large railroad diesels lined up, side-by-side on separate tracks.
The WCC pump station is probably the world's largest interior drainage pump station. To bear the weight and vibration of the structure and overcome challenges of constructing the facility on very soft soils, the foundation consists of 1,100 steel pipe piles driven over 100 feet below the base slab. The design was fast-tracked, and computational fluid dynamics modeling was employed to validate and optimize pump station hydraulics.
Due to the high cost of a traditional Design-Bid-Build, the Early Contractor Involvement delivery approach was used. ARCADIS dedicated a team of experts to complete the study and reports within weeks, instead of several months, and delivered the project on-time, on-budget, and meeting all established milestones.