FALLBROOK – In the early hours of Tuesday morning, Dec. 8, system operators for the Rainbow Municipal Water District noticed a large spike in the volume of water flowing through their pipelines. “That is never a good sign,” commented Juan Atilano, a superintendent for the district, “you don’t expect to see such drastic increases in flow, particularly right after a heavy rain.” Emergency crews were quickly dispatched to search for a leak, a task that was made more difficult by the recent heavy rainfall and the shutdown of major water importation pipelines.
Rainbow’s general manager, Dave Seymour, said, “Everything was wet, so looking for a leak in the dark was a challenge. On top of that we had our system set up to accommodate the Metropolitan Water District shutdown, so it wasn’t operating in a normal manner.” Seymour added, “We knew from the amount of water we were losing it had to be one of our creek or river crossings, so we focused our search in those areas.”
By mid-morning several customers south of SR-76 were without water. Eventually crews traced the break to a pipeline that crosses under the San Luis Rey River. Once the break was isolated water service was restored. The pipe, a 22-inch steel line, was installed in 1995 using directional drilling at a depth 30 feet below the river bottom. That method was chosen to reduce disruption to the sensitive environmental habitat.
According to Seymour, “We use to have five pipelines crossing the river, but in the past whenever a pipeline would break the decision was made to abandon it to save costs. Now with this break we are down to a single 14-inch pipeline, and that is a pretty scary.” In August, the current Board of Directors approved a project to begin restoring some of the abandoned connections. An engineering firm will videotape the inside of old pipelines to determine what needs to be done to return them to service.
The District will use the same engineering company, RBF Consulting out of San Diego, to help with this pipeline repair. “At 30 feet deep we probably won’t be digging it up to repair it,” said Seymour; “We are working with our consultant to determine the best way to repair or replace the line with the least environmental impact.”