COLUMBIA — City officials suspect that the simultaneous use of lawn irrigation systems in the Thornbrook neighborhood is likely responsible for recent drops in water pressure that have prompted a precautionary water boil advisory since Monday.
The advisory affects about 600 homes.
Water flow data loggers and Thornbrook residents have been reporting sharp water pressure drops, specifically around 4 to 5 in the morning, since last week, Columbia Water and Light spokeswoman Connie Kacprowicz said.
Until now, the area has had no water pressure issues, Kacprowicz said. Increased use of irrigation systems due to recent high temperatures and dry weather could be driving the problem, the department said in a Wednesday news release.
The subdivision will remain under the boil advisory until Water and Light can be sure water pressure won't drop below 20 pounds per square inch.
“It does appear there is a correlation between the low water pressure and the neighborhood irrigation systems,” Kacprowicz said. She said there are about 500 irrigation systems in the neighborhood.
It's not a supply problem but a demand problem, Kacprowicz said. She said there is plenty of water, but the irrigation systems are turning on at about the same time, thus demanding water all at once.
Kacprowicz said recent construction at Beulah Ralph Elementary School also has been investigated as a possible cause for the pressure drops, but no evidence for that theory has been found. The city also found no problems in the water distribution system, according to the news release.
A voluntary street-by-street watering schedule has been put in place for Thornbrook and the surrounding subdivisions of Bradbury Estates, Creek's Edge, Steeplechase and Wyndham Ridge. It asks residents to set irrigation system timers to go off between midnight and 4 a.m.
If that strategy improves the pressure, then the boil advisory will be lifted, according to the news release. If there is no improvement, the city will suggest that people irrigate on alternating days.
Meanwhile, Water and Light will be looking for a long-term solution.
Supervising editor is Scott Swafford.