According to historical documents, the first mention of a new water treatment plant was on March 5, 1941. A committee had been appointed by Mayor J.E. Anderson to study and recommend options to supply additional water to El Paso. Fort Bliss was expanding with the beginning of World War II, and additional water was needed.

The W.E. Robertson Water Treatment Plant, named for an El Paso Water Board chairman, was completed in 1943 to serve a population of 107,000. The plant was expanded in 1949, and in 1967 the Elwood J. Umbenhauer Plant was constructed. Together, these two plants are called the Canal Street Water Treatment Plant provide 40 million gallons of water per day. They use conventional treatment technology to purify Rio Grande surface water during the peak season (approximately February to October, when water is released from Elephant Butte Dam to serve downstream users). The plants are utilized as a blending reservoir during the non-irrigation season for water pumped from wells. The Robetson/Umbenhauer Water Treatment Plant provides water to central and west El Paso.