The ruptured pipe was a 100-year-old, 36-inch trunk line under Sunset Boulevard…

Brief

The 100-year-old, 36-inch water trunk beneath Sunset Boulevard—already on LADWP’s list for replacement with a $280M, 6.4-mile project scheduled for 2031-2035—ruptured five years before planned work, creating a sinkhole. LADWP replaced <1 mile last year versus a 1.1-mile goal; at 3.5 miles/year the 550-mile system sees a 157-year cycle, outlasting riveted-steel’s ~100-year life.

Why it matters

The ruptured pipe was a 100-year-old, 36-inch trunk line under Sunset Boulevard that LADWP had scheduled for replacement in 2031; LADWP budgeted $280 million to replace 6.4 miles of this exact trunk line, with design ongoing and construction planned 2031-2035—the pipe burst five years before crews would start.

Key details

Last fiscal year LADWP aimed to replace 1.1 miles of trunk pipe but replaced less than one; Los Angeles has roughly 550 miles of trunk line, so at the department’s new target of 3.5 miles/year each mile would be replaced every 157 years.

Riveted steel trunk pipe has an expected life of about 100 years; a 1921 trunk line ruptured in 2014 near UCLA, releasing roughly 20 million gallons and submerging Pauley Pavilion—today’s collapse is the same street and vintage, illustrating a gap between material lifespans and political replacement schedules.

The 100 year old pipe that just sinkholed Sunset Boulevard was already on LA's replacement list. Construction was scheduled for 2031.

LADWP budgeted $280 million to replace 6.4 miles of this exact 36-inch trunk line. The project is still in the design phase. Work starts in 2031 and finishes in 2035. The pipe burst 5 years before the first crew would have touched it.

The replacement math explains why this keeps happening. Last fiscal year, LADWP's goal was to replace 1.1 miles of trunk pipe. They replaced less than one. LA has roughly 550 miles of trunk line. Even at the department's new target of 3.5 miles a year, each mile gets replaced once every 157 years.

Riveted steel pipe lasts about 100.

And Sunset Boulevard has run this exact experiment before. In 2014, a trunk line from 1921 ruptured under Sunset near UCLA and sent roughly 20 million gallons through campus, submerging Pauley Pavilion. That break is what made LA's aging pipes national news and launched the current replacement program.

Twelve years later: same street, same vintage of pipe, same aerial footage.

Cities schedule pipe replacement on political time. Pipes fail on material time. LA is replacing 100 year pipes on a 157 year cycle, and this morning is what the gap between those two numbers looks like.

Tommy B. 🇺🇸 (@realtommybibi)

Sunset Boulevard is closed indefinitely in West Hollywood

after a massive, 100-year-old water main ruptured early Thursday morning, creating a large sinkhole directly under the traffic light at Sunset Boulevard and Holloway Drive

Video

— https://nitter.net/realtommybibi/status/2077843063700070500#m