2023
El Paso, Texas

Structural Strengthening of the Sunset Reservoir

The Sunset Heights Pump Station and Reservoir in El Paso, Texas, is a vital infrastructure facility that has been distributing drinking water to the city since the 1920s. Owned and maintained by El Paso Water (EPWater), this historical site comprises two 4-million-gallon concrete water tanks and a pumping station. The aging structures were in the process of being inspected for repair when a sudden earthquake in 2020 struck 200 miles east of El Paso, caused significant damage to one of the reservoirs, resulting in leaks.  The first tank was repaired and strengthened in 2021 and the second tank was repaired and strengthened in 2023. While both projects were similar in nature, the repair and strengthening procedure, and the unique considerations involved in managing the site mobilization shown here are from the tank project completed in 2023. 

Existing Conditions of the Reservoir: Cracks, Spalling, and Corrosion

The structural repair project was prompted by the deteriorating condition of the existing reinforcedconcrete elements within the tank. Underwater inspection via submarine cameras showed spalling hadoccurred on multiple columns and beams, exposing corroded rebar. There were also significant cracks on the tank lid (i.e. roof), which is only 3in thick with minimal steel mesh reinforcement. After rain the lid was described to look like a leaking sieve. A major crack was observed on the south wall of the tank, which may have occurred after the 2020 earthquake. To mitigate these problems, EP Water accelerated its plans for structural repairs. The final decision on the extent of the repairs, however, had to be determined after the tank was emptied, making collaboration between the owner, EOR, and contractor critical. The repair included:

• Sealing cracks

• Patching spalls

• Replacing joint material

• Strengthening the interior of the tank with carbon fiber reinforcedsystem

• Applying a UV-resistant coating on top of the tank lid tank

sunset reservoir

Conclusion

The repair and structural strengthening of Sunset Reservoir in El Paso, Texas, project successfully restored the integrity and functionality of the aging water tanks. Work involved repairing concrete spalls, routing and sealing over 1,300 LF of cracks, replacing joint material, and strengthening the inside ofthe tank with 93,969 ft2 of CFRP system. This was a unique project that posed many challenges for the contractor including limited access to the tank-inside, and large-opened surface area. Overcoming the challenges required outside-the-box solutions and close collaboration among the stakeholders. From start to finish, the work was done in six months, as originally planned, ensuring the continued distribution of safe drinking water to the residents of El Paso for years to come.