The dam system is the country's largest hydraulically-operated steel gate dam system. The dam is a reliable and cost-effective solution that is expected to last for decades.

This system was found by experts to be the most safe, reliable, cost-effective and durable while allowing the lake to transition into a river during major water flow events.

How the Dam Works 

The steel gate system consists of eight fabricated steel gates mounted onto a new roller-compacted concrete foundation and new reinforced concrete spillway slab about 100 feet downstream from the existing dam.

Using hydraulic lifts, these gates can be lowered to allow storm waters to pass through and raised to capture the tail end of the flow to re-establish the lake.  About two feet of water can pass over the top of the gates while they are in the fully-upright position. 

STATS
Each gate is: 
106 feet long 
17 feet tall 
Weighs 260,000 pounds 

The new piers are about nine feet wide on the upstream side and four feet wide on the downstream side. 

More than 20 technology alternatives were explored before choosing this system to replaced the original inflatable bladders.  

PROJECT PARTNERS 
In Tempe, we believe in shopping local and working with the best experts available. For this project, we were able to do both. Contractors for this project included: 

Tempe-based PCL Construction was the prime contractor.
Phoenix-based Gannett-Fleming was the engineering consultant.
Steel Fab fabricated the gates with Phoenix-based Schuff Steel. 

REGULATORY AGENCIES
Arizona Department of Water Quality
Army Corps of Engineers
FEMA
Flood Control District of Maricopa County

COST
The cost of this project, including removal of the previous dam system, was approximately $47 million.  

VALUE
Beyond providing flood control to make our city safer and allow development, Town Lake has benefitted our city so far with more than $2 billion in economic impact. Approximately 40,000 people work within a mile of Tempe Town Lake and 4,000 people live near its shores.

As a result of 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 beautiful, relaxing community gathering place known throughout the world.  

Photo by Lawrence Sutherland

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