ANDERSON, Ind. — Call it the perfect water leak.

Or, “a classic case of infrastructure decay,” which is how Water Department Superintendent Tom Brewer describes what has consumed the attention of top city officials since Wednesday morning.

That’s when an Anderson Power and Light Company employee working at the Wheeler Avenue substation saw water bubbling up from the ground between the substation and White River.

He notified the water department, which brought in excavating equipment and began digging to investigate.

What they found initially was bad enough.

A World War II-era, 24-inch concrete main that feeds raw water from eight city wells — and supplies about 50 percent of Anderson’s daily water needs — through the Wheeler Street Water Treatment Plant had failed. Underneath that supply line is an equally large distribution line that carries treated, or finished, water out to customers.

It, too, was leaking, “and that immediately doubled our problem,” said Deputy Mayor Pete Heuer.

At the highest rate, before engineers and construction workers could stanch the flow, each leak was sending 2,000 gallons of water per hour cascading into the White River.

Which created another serious problem.

Dropping water pressure.

Maintaining proper water pressure is vital to ensuring a safe water supply, Brewer said. Water pressure is what prevents bacteria and other contaminants from infiltrating the water system.

The water pressure in Anderson’s system normally is 60 pounds per square inch. But with the two leaks, the department was not able to maintain that pressure.

“We were facing a nightmare,” Brewer said Thursday. A possible citywide boil order if the pressure fell too low, and the shutdown of manufacturing options at the water department’s largest customer, Nestlé USA, which uses between 2.5 and 2.7 million gallons each day.

Through the early morning Thursday, city officials kept Nestlé plant managers updated on the leak, said Interim Economic Development Director Greg Winkler. The company agreed to reduce the number of production lines in operation.

“We want to help preserve water resources for the community and have temporarily reduced production in our plant facility as the city of Anderson works to repair the leaks in the water line,” Nestlé spokeswoman Shannon King said in a prepared statement. “We are currently running only two of six lines. We hope this situation can be resolved as quickly and safely as possible, as we are concerned about the impact this will have on our business as well as the community.”

At the same time, a backhoe was used to hold a temporary patch in place on one of the leaks that cut the flow in half.

Together, those actions helped stabilize the water pressure at about 50 pounds per square inch, more than enough to maintain a safe water supply.

And buy time.

Fortunately, two engineering firms, American Structurepoint of Indianapolis, and M K Betts Engineering & Contracting of Anderson were already “assets on the ground” working on an expansion of Anderson’s wastewater treatment plant, Winkler said.

Both companies immediately offered help in repairing the leaks. They were joined by F.A. Wilhelm Construction, an Indianapolis firm also working on the treatment plant construction.

Complications abound.

Pipes, pumps and valves will need to be replaced. And reaching the areas where excavation will be necessary, required clearing away brush and debris first.

In addition, because of the substation’s location, underground and above-ground power lines crisscross the areas where crews will be working.

“This is a really complex project, even for these companies that are experienced with this kind of work,” said Mayor Kevin Smith while visiting the site of the leak Thursday.

Brewer said it may take several days to complete the repairs.

While dealing with the first leak Thursday, utility crews repaired a second, although less serious, broken water main.

The second break occurred in a 4-inch line on Nursery road between eights and Sixth Streets, about 10:30 a.m. That break sent water gushing through the yards of neighborhood houses and took about two hours to repair.

Find Stu Hirsch on Facebook and @StuHirsch on Twitter, or call 640-4861.