Location

Portland, OR

Start Date

28-6-2016 1:30 PM

DOI

doi:10.15142/T320628160857

Description

After the existing Tempe Town Lake downstream dam failed unexpectedly in 2010, the City of Tempe, AZ, USA was tasked with designing and constructing a replacement dam to maintain their lake, pass flows in the ephemeral Salt River, and deliberately lower to avert flooding. Through an alternatives evaluation process, a hydraulically operated steel gate system was selected from a field of twenty studied alternative configurations to replace the existing rubber bladder system.

The gate design produced eight 32.3 meter (106 foot) long, 6.4 meter (21 foot) tall, and 118,000 kilogram (260,000 pound) steel gates operated by single-acting hydraulic cylinders and powered by a power unit featuring two 1,893 cm3/s (30 gpm) axial piston pumps each powered by a 37 kW (50 hp) motor. With local and remote monitoring and control capability, the system is designed to control the gates under automatic or manual control mode.

The design also includes a foundation seepage control and collection system using a cement-bentonite cutoff wall and drainage blanket; a scour wall; a stilling basin designed to accommodate variable crest elevations; instrumentation and controls designed to maintain the recreational lake while preventing unintended flooding; and an operations, maintenance and dam monitoring plan all designed to maintain dam safety, avert flooding, and preserve the City of Tempe’s valuable resource, Tempe Town Lake.

This paper presents the selection, approach, challenges and results of designing the hydraulically operated steel crest gate system designed to maintain Tempe Town Lake and deliberately lower to avert flooding.

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Jun 28th, 1:30 PM

Designing a Steel Gate Dam Across an Ephemeral River – Tempe Town Lake Dam Design

Portland, OR

After the existing Tempe Town Lake downstream dam failed unexpectedly in 2010, the City of Tempe, AZ, USA was tasked with designing and constructing a replacement dam to maintain their lake, pass flows in the ephemeral Salt River, and deliberately lower to avert flooding. Through an alternatives evaluation process, a hydraulically operated steel gate system was selected from a field of twenty studied alternative configurations to replace the existing rubber bladder system.

The gate design produced eight 32.3 meter (106 foot) long, 6.4 meter (21 foot) tall, and 118,000 kilogram (260,000 pound) steel gates operated by single-acting hydraulic cylinders and powered by a power unit featuring two 1,893 cm3/s (30 gpm) axial piston pumps each powered by a 37 kW (50 hp) motor. With local and remote monitoring and control capability, the system is designed to control the gates under automatic or manual control mode.

The design also includes a foundation seepage control and collection system using a cement-bentonite cutoff wall and drainage blanket; a scour wall; a stilling basin designed to accommodate variable crest elevations; instrumentation and controls designed to maintain the recreational lake while preventing unintended flooding; and an operations, maintenance and dam monitoring plan all designed to maintain dam safety, avert flooding, and preserve the City of Tempe’s valuable resource, Tempe Town Lake.

This paper presents the selection, approach, challenges and results of designing the hydraulically operated steel crest gate system designed to maintain Tempe Town Lake and deliberately lower to avert flooding.