Within three hours an estimated 500,000 gallons of water was lost from the City of Sequim’s reservoir causing the surrounding streets to flood.

A crack stretching about 10 feet along the bottom of an 8-inch water pipe was at the heart of the problem that occurred about 10 p.m., Thursday, April 7. By 11 p.m., city crews and local law enforcement had closed the street and were working to locate source of the flooding. By 1 a.m., the water was shut off and the break was isolated, said Matt Klontz, City of Sequim engineer.

As water is conveyed via the water main, the pressure often causes the pipes to vibrate, Klontz said. The ongoing vibration against large, 4-inch rocks found in the pipe bedding at the location of the crack is thought to be the cause of the break.

“The good news is the (escaped) water was contained from curb to curb,” he said.

Another silver lining of the break and resulting flooding was the information city officials were able to glean.

The water lost was flowing at a rate of about 3,000 gallons per minute, which is the “fire flow requirement,” Klontz said.

“The water was delivered at the rate that it’s designed to — so in a strange way we were able to validate the fire flow,” he said.

“Unfortunately,” however, the road will need repaired, he said.

About 200 linear feet of asphalt on North Seventh Avenue between West Spruce Street and West Fir Street will need fixed given the water caused the road to separate and “float,” Klontz explained.

The road is open to traffic, but a section of the bike lane, mid-block, on the east side of North Seventh Street likely will remain closed until the repairs can be made or the pavement is patched.

“Fortunately, breaks of this size are unusual,” Klontz said.

The cost and schedule for the repair have yet to be determined.