A pipeline that spans almost the entire length of San Diego County is back in use after engineers spent weeks patching a massive crack in the pipe's infrastructure.
The San Diego County Water Authority (SDCWA) discovered a leak in September to a portion of its 90-inch Pipeline 4, which has carried water since 1966 from the Skinner Water Treatment Plant near Temecula down to the Otay Reservoir near Chula Vista.
NBC 7 was the only news media outlet invited inside the pipe in September before repairs began. The pipeline was shut off Sept. 16 with the cooperation of the Water Authority's member agencies.
Engineers spent weeks 20 feet underground near Bonsall using a wallpaper-like carbon fiber to line the split.
SDCWA Principal Engineer Brent Fountain said the lining was the quickest fix and would last for years.
Before repairs, water from outside the pipe was seeping inside. Giant steel bulkheads were welded into place so that engineers could safely work on the fix.
The water authority was able to locate the abnormal crack through routine checks to the system. If it got worse, it had the potential to "wash out this entire area," Fountain said.
About 400 cubic feet of water usually passes through the pipe every second.