On Monday, Feb. 5, at about 5:12 PM, the city of Colusa temporarily “ran out of water.” Thanks to the fortuitous timing of the outage, rapid reporting by city residents, and a quick response from city staff, faucets around the city were operational again in just eight minutes.
Colusa City Manager Jesse Cain filled the city council in on the incident at last Tuesday’s city council meeting.
“In a nutshell, what happened was our well’s communications with the tanks failed,” Cain told the council. “It was our SCADA (Supervisory Control and Data Acquisition) control, which essentially is just a level sensor in the tank, that as the tanks go up and down, it communicates with the wells and lets them know when to come on and off. It never called for the wells to come on.”
It also failed to set off a total of four low-water alarms, Cain added.
“Everything failed last night. That’s why we were ran out of water,” he said.
After the meeting, Cain said that the city “running out of water due to catastrophic failure” has been one of his worst fears since he started working for the city in 1999. Luckily, that didn’t end up being the case.
In the span of about 15 minutes that evening, Cain said he received somewhere in the neighborhood of 100 calls regarding the water outage. When the first few calls came in, Cain just happened to be about four blocks from the well.
“My first reaction was to go turn on the well by hand, if it wasn’t running,” Cain said.
When Cain turned the well on and residents immediately started getting water again, he realized that the situation was not as bad as he feared.
“The city’s tanks are strictly for water pressure. We just lost the pressure – the ability to push it out of the faucet,” Cain said. “I know that for a fact because as soon as I kicked on the well manually, people started getting water again. Once I got the well back on by hand, and people started telling me they had their water back, I went to the water towers and called everyone in to work.”
After they were called in, city staff kicked on a second well to help fill the city’s water tanks more rapidly. Cain said that he doubled chlorine dosages, in the event that the water had somehow been contaminated, to ensure then water was safe for drinking.
“We kept checking it until 11 PM that night,” Cain said. “The next day, we went out and pulled all of the distribution samples in all locations, to just verify that nothing got in the water and contaminated it. I was later notified by the lab that all samples came back good.”
Cain estimated that the well was non-communicative for a period of about two hours, before the city’s two water tanks – with a combined capacity of 250,000 gallons – went dry. Between 8:00 and 8:30 PM, both tanks were “100 percent full” Cain said.
The SCADA system, which Cain described as brand new, was installed a couple of months ago. Cain said that the morning after the incident he spoke with an expert who believed that there was some type of power glitch that “screwed the system up.” Luckily, the glitch occurred at a time where most residents were home, and many were using water – otherwise, things could have turned out a lot worse, Cain said.
“If this would have happened at 11 PM when everyone was sleeping, our system could have drained and this could have been way bad,” Cain said. “The immediate public reaction was a blessing in disguise, in a sense. But hopefully, nothing like this happens again in my lifetime here.”
In response to the control system’s failure, Cain said that the city is putting further redundancies in place to ensure it won’t happen again.