Tempe Town Lake Downstream Dam Replacement

The $45 million Tempe Town Lake Dam is an engineering marvel as one of the country’s largest hydraulically controlled steel-gate dams. The dam receives flows from the Salt River as it passes through the City of Tempe, Arizona, forming what is known as “Tempe Town Lake.”

As a result of the Tempe Town Lake, Tempe now hosts many world class events, and people can take part in a variety of recreation opportunities. It has transformed a dry riverbed into a beautiful, relaxing community gathering place known throughout the world.

After the dam’s previous rubber bladder failed in 2010 and drained 1 billion gallons of water from the lake, the City engaged GFT to study the alternatives for a replacement and develop a new design to maintain the lake, pass flows in the Salt River, and lower the pool elevation to avert flooding. The team conducted an alternatives evaluation workshop with project stakeholders, performed hydrologic and hydraulic analyses associated with the design inflow conditions, prepared preliminary design plans, and performed a failure modes and effects analysis to compare the shortlisted alternatives.

The selected replacement is a hydraulically operated steel gate system, consisting of eight 106-foot-long by 17-foot-tall steel gates supported by seven concrete piers, two abutment walls, and a 21-foot-thick concrete foundation. GFT also prepared final design and construction documents, including geotechnical investigations, coordinated with the gate vendor and construction contractor, and obtained a dam safety permit from the Arizona Department of Water Resources.