The water shortage became so desperate at one point the town officials used volunteer fire companies to haul water from Hagerstown's system to the town's reservoir.
"We thought we were in the clear. For the last four weeks, the reservoir stayed at 19 feet with no problem," Kauffman said.
But Kauffman said town officials noticed water levels were dropping on Monday. In a matter of hours, the level had fallen from a little more than 18 feet to about 17 feet.
David Baker, superintendent of Boonsboro's water and sewer system, said he traced the problem to an 8-inch water main on Md. 34 between Boonsboro and Keedysville. The line carries water from the Keedysville spring to Boonsboro's reservoir.
"The pipe was cracked all the way around," he said.
Baker said it was not hard to find; the water was bubbling up on the side of the road.
Baker said it took about five hours to stop the leak. He said he put a clamp on it.
Kauffman said he believes the reservoir should be able to recover on its own.
"It's wait-and-see to see if that's the only leak," he said.
Baker said he does not know why the pipe broke but added that it was installed in 1959.
"It's just like everything else. It wears out," he said.
Kauffman said the line will be replaced when Boonsboro and Keedysville build a regional water filtration system. The state has offered a $1.5 million grant to help pay for the work.