Tempe Town Lake Downstream Dam Replacement

Tempe Town Lake Dam is the largest hydraulically controlled crest-gate dam in the nation

The $45 million Tempe Town Lake Dam is an engineering marvel as the country’s largest hydraulically controlled steel-gate dam. 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.

What We Did

After the dam’s previous rubber bladder failed in 2010 and drained 1 billion gallons of water from the lake, the City engaged Gannett Fleming 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. Gannett Fleming 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.

Key Features

  • Hydraulically operated steel gate system.
  • Eight 106-foot-long by 17-foot-tall steel gates supported by seven concrete piers and two abutment walls.
  • The largest gate system of its kind in the nation.

Awards & Recognition

  • Best in Concrete, 2016, Arizona Chapter of the American Concrete Institute and International Concrete Repair Institute.
  • National Engineering Excellence Grand Award, 2018, American Council of Engineering Companies, Engineering Excellence Awards.
  • Project of the Year in the Greater than $10 Million category, 2017, American Society of Civil Engineers Phoenix Branch, Project of the Year Award.
  • Best Project Award, 2016, Engineering News-Record, Regional Best Projects.
More Project Details

Security & Public Safety

Dams & Levees



The long-term performance of steel under extreme temperatures ensures the dam's structural reliability and durability.

Dam replacement is more stable and will last 50 years longer than previous dam.

Serves as a flood control tool, recreation venue, and an economic development center.