Since August 2010, BAR Constructors Inc. of Lancaster, Texas, has been replacing vertical, mixed-use pumps with Flowserve Corp. concrete volute pumps at six pumping stations along the chronically flood-prone Trinity River in Dallas. Due for completion in late 2012, the project is funded primarily through a $1.35 billion bond program issued in 2006 that's also paying for street, sidewalk, and facility improvements.

Concrete volute pumps have performed well in nuclear reactors overseas for three decades. They're essentially a wet-well/dry-well pump with a volute made from concrete. The design allows the use of very large-diameter impellers that wouldn't be practical with either cast metal or fabricated because of manufacturing challenges. It also allows for a shorter drive shaft.

Although details for the city's Trinity Watershed Management Department's installations vary from station to station, Figure 3 (above) shows a typical plan view. The pumps are on one side of a central drive and the electrical room is on the opposite side. The electrical room's location will vary depending on site constraints. The fore bay, trash racks, and debris management areas are to the immediate right of the pump bay.

Figure 4 (right) is an elevation through the pump station and shows the relationship between the fore bay area, suction box, suction bell, and volute.

Learn more about the project - including before-and-after capacity analyses of the city's six pumping stations - in our November issue.

To subscribe to the magazine or receive our weekly e-newsletter, visit