Los Angeles is confronting significant challenges related to its aging water infrastructure, which serves over 400 million gallons daily through a vast underground network of pipes. Much of this system, installed more than a century ago, is increasingly vulnerable to leaks and ruptures, underscoring the difficulties faced by the Los Angeles Department of Water and Power (DWP) in maintaining reliable service amid budget and logistical constraints.
On July 16, a 110-year-old, 36-inch steel trunk line ruptured beneath Sunset Boulevard in West Hollywood, releasing approximately 17 million gallons of water and creating a large sinkhole. This incident followed a similarly large break in 2014 in Westwood, where a pipe failure resulted in around 10 million gallons flooding parts of the UCLA campus. These two events highlight the risks associated with aging pipes in some of the city’s most affected areas, including the Westside, which has recorded the highest number of leaks over the past decade.
The DWP manages an extensive system comprising about 6,780 miles of distribution pipes (mains) and 547 miles of trunk lines that deliver water from reservoirs to neighborhoods. Assessments from recent years indicate that more than 30% of these mains are over 80 years old, with at least 6% classified as high priority for replacement based on factors such as pipe age, leak history, material, soil corrosiveness, and pressure variations. For trunk lines, although fewer have received poor condition grades, the utility recognizes the critical nature of these major arteries and aims to accelerate replacement efforts.
Addressing the infrastructure gap, the DWP is executing an $8-billion, five-year Water System Capital Plan focusing on pipe replacement and repairs. This year, the utility expects to replace about 45 miles of main lines, nearly one-third of which are rated as high priority. However, replacement of trunk lines remains limited, with just over a mile projected for this fiscal year, though plans call for increasing this to five miles annually within four years. Nonetheless, officials acknowledge that substantial funding, personnel, and the complexity of coordinating projects — which must minimize impacts on traffic and communities — pose ongoing challenges.
To mitigate risks, the DWP has deployed acoustic leak detection technology designed to identify small, unseen leaks before they escalate into major failures. Despite these efforts, utility representatives caution that unexpected breaks will continue to occur, partly because the scale and age of the infrastructure make full, immediate replacement unfeasible.
Experts emphasize that Los Angeles is not unique in facing these problems; across the United States, water systems installed in the early 20th century require extensive renewal. A recent national report estimated that over the next 25 years, drinking water infrastructure needs will reach $2.4 trillion, with an annual additional investment of $56.6 billion required to prevent dramatic rate increases and ensure system resilience. Without sufficient investment, consumer costs could rise significantly, and utilities risk operational strain due to unplanned maintenance and employee burnout.
As Los Angeles grapples with this sizable infrastructure liability, the recent West Hollywood rupture has brought renewed attention to the fragile state of its water delivery network. Maintaining these critical but aging underground arteries is a complex, costly task that underscores the broader challenge of sustaining modern urban infrastructure in an aging city.