Expanding Raw Water Supply for Oklahoma City

“As a result of the 1889 land run, Oklahoma City went from a population of a few dozen to over 10,000 in a few days. In the early years local streams and hand dug wells were relied upon; however, by the time of statehood, the population was over 60,000,” said Brent Hauser, chief system engineer at CDM Smith. “Projects to capture water from a nearby river and reservoirs were sufficient until the 1950s, when the Oklahoma City Municipal Improvement Authority was formed.” Severe drought conditions in the 1950s pushed the city to secure the short-term and long-term vitality of its water supply. In 1952, water sourcing issues, partic­u­larly declining ground water, affected not only the city, but 40% of the entire state’s population. In response the Oklahoma City Municipal Improvement Authority (OCMIA) located a source of quality water and managed construc­tion of the original Atoka Pipeline. That project ensured 50+ years of growth and stability for Oklahoma City.

To transport the water from this new source, the Atoka Pipeline was constructed in the 1960s. This pipeline consists of a 100-mile-long, 60-inch-diamater pre-stressed concrete pipeline running from Southeast Oklahoma to Oklahoma City, supported by six pump stations. The pump stations, each now equipped with four 2,500 horsepower pumps, transfer over 80 million gallons per day to Oklahoma City.

While the initial pipeline supported the area for years, the need to transport greater quantities of water grew as the city and surrounding areas prospered. Five decades after construc­tion of the initial pipeline, projected water demands revealed that the city and surrounding areas would exceed their existing water supplies. OCWUT, successor to the original OCMIA, had to respond to increase raw water supplies and enlisted the help of CDM Smith’s team of water experts to expand their raw water system. 

To assess the overall needs of the area and the scope of the water supply expansion, the team completed initial studies and conceptual designs after evaluating water sources and delivery options, then developed a plan for phased pipeline improve­ments to success­fully meet the projected water demands through 2060. Modeling pipeline alter­na­tives to determine the most cost-effective and feasible options included elements of operations modeling, surge modeling, and config­u­ra­tion analysis for the pump stations. CDM Smith addi­tion­ally provided estimates for probable construc­tion costs and operations costs, as well as conducting detailed hydraulic analysis and water supply reliability analysis. 

The team also supported OCWUT during legal proceedings, assisted with land acquisitions, and managed impacts to Sardis Lake and the Kiamichi River. CDM Smith supported the mediation process working with state agencies, federal agencies, and Native American governments, leading to an historic agreement in 2016 as final congressional and presidential approvals were received.

The significant modeling, design, and planning efforts helped inform the best plan to construct a second pipeline to transfer the additional water needed to support the growing area. To provide potable water to the Oklahoma City area, a 100-mile-long, 72-inch diameter pipeline, parallel to the original, is under construction. This additional pipeline will initially include three new pump stations, plus provisions for three additional stations as the demand for water assuredly grows. “From technicians managing day-to-day operation of the system, to engineers planning future projects, to accountants monitoring revenues and expenditures, to attorneys and contract specialist guiding dozens of contractors, OCWUT professional staff has kept this and dozens of other projects on-track and focused,” Hauser said.

The programmatic and design work the CDM Smith team provided to OCWUT stands as the largest engineering services contract in Oklahoma City history. The vast coordination of services to provide water to not only Oklahoma City, but over a dozen adjacent communities will serve the region for decades to come.