City’s lost water rate still decreasing, surveys show

The percentage of water the city treats that doesn’t reach the regional water system’s more than 35,000 meters decreased from 2016 to 2019, according to a survey the Arkansas Department of Health released earlier this month in response to a records request.

Unaccounted for, or nonrevenue, water decreased from 27.72% of production in 2016 to 24% in 2019. The city’s 2021 budget projected water fund revenue of $19.6 million and expenses of $18.4 million.

“If you have a municipal water system that indicates they have less than 15% of unaccounted for water, they’re really doing well,” said Jeff Stone, director of the Health Department’s engineering section. “Things like leaks that you need to track down contribute to unaccounted for water. Also included in that group is fire hydrant flushing that wasn’t metered and accounted for or perhaps even other uses at a treatment plant that wasn’t accounted for.

“To come up with a good number for unaccounted for water the utility has to try to account for all of those identifiable uses that didn’t go through people’s water meters and then compare it to water produced

and water sold. If they get under 15%, especially for a water system the age of Hot Springs, and track down enough water leaks to get it that low, they’ve done very well.”

Production required for a day of average demand decreased from 15.12 million gallons in 2016 to 13.03 million gallons in 2019. Production required for a day of maximum demand decreased from 20.11 million gallons to 15.60 million gallons.

“It is very encouraging that we continue to see a decrease in (unaccounted for water) over the past two surveys,” City Manager Bill Burrough said. “Unfortunately, it is not uncommon for utilities our age to have higher (unaccounted for water), but it has been a priority and will continue to be so. I am pleased to see this drop to 24%. Staff will strive to continue to lower this number.”

The 2019 survey continued to list a 28.33 million-gallon a day combined production capacity for the Lakeside Plant that treats water from the city reservoir at Lake Ricks and the Ouachita Plant that treats water from upper Lake Hamilton, despite the Health Department lowering the plants’ production ratings in 2018.

Crist Engineers, the city’s water system consultant, requested the downgrades, telling the Health Department its ratings didn’t account for time the six filters at Lakeside and nine at Ouachita are offline for backwashing. Lakeside’s rating was lowered from 6 million gallons to 4 million, and Ouachita’s fell from 22.33 million gallons to 21 million.

Production capacity will increase by 15 million gallons a day when the city completes the $100 million Lake Ouachita water supply project. The city secured a 23 million-gallon average day allocation from the U.S. Army Corps of Engineers in 2017, paying the federal government $444,440 a year to store the water behind Blakely Mountain Dam.

The cost is the city’s share of $12.4 million in storage costs the Mid Arkansas Water Alliance is paying down over 30 years. The money compensates hydropower producers for water diverted from power generation to municipal supply. Lake Ouachita was built under the Flood Control Act of 1944 for the purposes of flood control and hydroelectric power. Using the dam for purposes other than its congressional mandate requires storage to be reallocated from the conservation pool.

The Southwestern Power Administration sells hydroelectric power the dam generates to utilities in a six-state region, the Corps has said. The Corps receives revenue from the sale, the rates of which are structured to allow the Corps to recover costs incurred by the federal-hydropower program.

The revenue repays the public for its investment in the program. Southwestern receives a credit applied to its share of storage costs that is equal to the revenue that’s no longer accruing to the Corps as a result of water being reallocated from power generation to municipal supply.

The city is building an intake behind the dam and a raw waterline to the 15.75 million-gallon a day plant it will build off Amity Road. The project is scheduled for completion in 2023. A California lab that tested water samples collected from the intake location said it was the cleanest surface water they had tested, the city said.

“There should be very low turbidity and suspended solids in it,” Stone said. “It will be one of the best sources in the state when they tap into that.”

Stone said keeping the 73-year-old Lakeside Plant in service after the new water comes online may not be the best use of city resources, as Lake Ricks becomes an unreliable raw water source during prolonged stretches of hot and dry weather.

“At first glance, it would look like that reinvestment may not be the best choice for a source that’s not that reliable during the summertime period,” he said. “But we don’t rely on first glances. We rely on a pretty rigorous analysis and cost-benefit look. That’s what their consulting engineering will help them with.”

The Health Department told the city it needed to acquire additional supply when production exceeded 80% of treatment capacity 50 times during the summer of 2012, a strain caused by a hot and dry weather pattern and tourists creating more demand for water.

“During those periods water demands really ramp up and challenge a water utility to provide the quantity of water its customers need,” Stone said. “The steps they’re taking is going to put them in a really good position to provide that level of service for the customers.”

The Health Department said it’s authorized to prohibit utilities from connecting new customers until supply concerns are addressed, but it’s never taken action against a utility that fails to plan for additional supply after reaching the 80% threshold.

“Water infrastructure is very expensive,” Stone said. “Utilities serving large municipalities have to plan for these improvements and put them in place. There’s a long period of planning and design involved and a significant price tag associated with that. It’s a significant challenge to these cities, but it has to be periodically done.”

The 2019 survey said the city’s distribution system has 6.83 million gallons of usable storage, which doesn’t account for the 3 million gallons from the Cornerstone elevated tank the city filled in August. Crist said the tank gives the city 11.38 million gallons of usable storage, or 73% of the maximum day demand the Health Department reported in its 2019 survey.

The Cornerstone tank gives the distribution system 20 million gallons of storage, but only about 55% can be distributed to all elevations in the more than

145-square-mile service area. The balance 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.

According to Crist’s calculations, the Cornerstone tank gives the city usable storage equal to

17 hours of production on an average day of demand. During a service disruption at either of the two plants, the readily available storage can continue serving the more than 90,000 residents who rely on the city for water.