New water tank increases city’s storage capacity
Water hovering behind Cornerstone Market Place has put the regional water system closer to the state-recommended 24 hours of maximum-day storage.
Members of the Hot Springs Board of Directors, which appropriated the $5.2 million for the Cornerstone tank project, turned valves that fill and draft the 3 million-gallon receptacle Thursday morning, but it was purely ceremonial. City Utilities Director Monty Ledbetter said the more than 200-foot-tall tank has been online for three weeks.
It’s the first elevated tank the city has built in more than 50 years.
According to the city’s weekly newsletter, it began filling the tank Aug. 14. The tank’s distance from the Ouachita Plant that treats water from the intake on upper Lake Hamilton requires the Music Mountain tank, where water from the plant is distributed to the city’s other storage tanks, to be valved off to fill the Cornerstone tank to the top of its 710-foot overflow elevation, John Keckler, Crist Engineers’ hydraulic modeler, said Thursday.
The board awarded Crist a more than $5 million contract to design and oversee the city’s $100 million Lake Ouachita supply project, which will add more than 20 million gallons a day to the city’s water portfolio. The Cornerstone tank will eventually be fed by the new 15.5 million-gallon-a-day plant the city will build off Amity Road. The new plant will treat the city’s Lake Ouachita allocation.
A 16-inch line connected to the 12-inch main on Central Avenue and a 24-inch line underneath the shopping center’s parking lot connect the tank to the distribution system. The 24-inch line is connected to the 20-inch transmission main that runs along the King Expressway. The transmission line is the distribution system’s main conduit, Keckler said.
Crist has been working on getting more use out of the line, developing a plan to send water from the Music Mountain tank directly to the elevated tank on Hollywood Avenue. Water currently gets pumped from the Ouachita Plant to Music Mountain, where it’s pumped more than 150-feet uphill to the twins tank north of the intersection at Albert Pike and Airport roads.
It’s then gravity fed to the Hollywood tank, which is more than 150 feet lower than the twins tank. Less pumping would be required if Music Mountain and Hollywood, which are close to the same elevation, had a more direct connection.
“We’re trying to eliminate the double pumping and get full utilization out of this water main that runs along the bypass,” Keckler said.
According to the master plan Crist developed for the water system in 2018, the Cornerstone tank
gives the distribution system
11.38-million gallons of usable storage, about half of the water the city’s two treatment plants produce on a maximum-demand day.
It increases total storage to more than 17 million gallons, but only about 65% can be distributed to all elevations in the more than 145-square-mile service area. The rest sits at the bottom half of ground-level tanks, essentially holding up water that’s available for distribution to all elevations at a pressure level of 30 pounds per square inch or greater.
“If there’s a power outage or a problem at a pump station, and if it’s a hot day, you’re in pickle,” Keckler said. “There was only about eight hours of leeway under that scenario. We’ve got more time with this tank online. The water is up in the air to fix the problem.”
The concrete base for the 140-foot-tall pedestal supporting the tank was poured in late 2018. Cables powered by more than 30 hydraulic jacks lifted the 700,000-pound steel tank onto the pedestal in January.
Tank contractor Chicago Bridge & Iron of Houston completed application of local artist Ryan Kahler Rooney’s “Welcoming Hills of Hot Springs” illustration onto the tank this spring, using 863 gallons of paint consisting of 18 different colors to cover the 30,500-square-foot space.
Ledbetter told those who gathered for Thursday’s ceremony that the omnidirectional presence projected by the tank has forever changed the city’s landscape. Mayor Pat McCabe said it will have a lasting effect on economic, industrial, business and residential development, as it’s part of the long-term plan to increase the regional water system’s supply and storage.
“Over the years to come we will be the envy of the world when it comes to our supply of water,” McCabe, referring to the more than 60 million gallons a day of surface water from lakes Hamilton, Ouachita and DeGray the city has secured rights to, told the gathering. “Twenty, 30 years from now we’re going to look back and say, ‘How was this done?’ It occurred because of the leadership of (City Manager) Bill Burrough and the city directors who saw fit to move forward in areas where we had challenges.”