Central Arkansas Water has two high-quality and well-protected raw water supplies, Lake Maumelle, located in West Pulaski County, is a scenic 13.9-square-mile reservoir that provides approximately 65 percent of daily system-wide demand. And, Lake Winona, a project that originated in 1936, located approximately 18 miles west of Lake Maumelle in the foothills of the Ouachita Mountains.
The Lake Maumelle area is comprised of 8,900 acres with approx. 70 miles of shoreline. Although, the lakes primary function is our water supply, it also serves as a public area for outdoor activity and sporting. We encourage families and members of our communities to take advantage of this scenic location and all the activities it has to offer, such as hunting, canoeing, kayaking, fishing, trails, and park areas.
The recreational use is regulated for protection of this vital resource, but with an understanding of these regulations and why they exist, we can partner to maintain the quality of our water and the preserve the public use of Lake Maumelle and surrounding property.
Lake Winona is also available for limited recreational use, such as fishing and boating. To protect water quality, the lake consists of two zones. While enjoying these areas, please be aware of the areas (or zones) that have been sanctioned for restricted access. These areas are limited to Water Utility personnel or law enforcement officers engaged in the performance of their duties.
A Little History
Studies that began in 1947 preceded the water utility’s development of a second source lake to meet the area’s growing demand for water service. Construction of the first source, Lake Winona, located approximately 18 miles west of Lake Maumelle in the foothills of the Ouachita Mountains, spanned from 1936 to 1938. The Lake Winona project began in 1936, immediately after the City of Little Rock purchased the local water system south of the Arkansas River from private owners.
With the assistance of consulting engineers, the water utility thoroughly investigated several prospective sources prior to selecting a site for the second reservoir. Along with the decision to build Lake Maumelle was a public vote on a new water rate schedule to finance the project.
The water utility initiated preliminary surveys and mapping of the Lake Maumelle site in February 1954 and completed the work in December 1954. Sub-surface investigations at the project site followed in March 1956. The studies proved favorable and the engineers proceeded with project design. In July 1956, water officials awarded the first major contract for construction of the dam on the Big Maumelle River. In June 1958, water from the new Lake Maumelle source flowed into the system for the first time. The overall project included two 30-million-gallon-per-day (MGD) constant-speed pumps and cost approximately $9 million.
In 1975, a third pump increased the firm capacity of the Lake Maumelle Pumping Station to 90 MGD. The pump, driven by a 2,250-horsepower (hp) motor, also added variable speed drive capabilities to the facility. In 1984, the water utility replaced the 2,250-hp motor and variable speed drive with a constant speed, 2,500-hp motor. The third pump, motor, associated piping, and electrical equipment cost about $1 million. In 1983, the water utility added a fourth, 30-MGD pump at a cost of $974,944. The last pump addition increased the station’s firm capacity to approximately 113 MGD.
In 1988, the installation of an emergency stand-by power generating station equipped the water utility with backup power in the event of a failure on the commercial electric system. The project included two 3,000-hp diesel engines; two 2,000-kilowatt generators; and variable frequency drive equipment. The generators have the capacity to power two of the 30-MGD pumps. This capability, coupled with the gravity supply from Lake Winona, can provide customers with up to 84 MGD (more than current average day demand) during a complete electrical power outage at the Lake Maumelle Pumping Station.
With the stand-by generating facility, the water utility also is able to control additional electric power costs incurred during peak demand periods.
In 2004, CAW completed construction of a second intake structure at the Lake Maumelle Pumping Station. The first phase of this installation included two 15-MGD pumps and the design for one additional 30-MGD pump. In addition to supporting the increased treatment capacity of the Jack H. Wilson Water Treatment Plant, the new $7.7-million intake enhanced the overall reliability and integrity of the raw-water system.
Water flows from the Lake Maumelle Pumping Station by way of 48-inch and 72-inch-diameter pipelines.
(Little Rock Municipal Water Works and its largest wholesale customer, the North Little Rock Water Department, merged July 1, 2001, into Central Arkansas Water. CAW is a metropolitan water system serving a population of almost 398,000.)