Lay more pipe
Sacramento’s aging water infrastructure gets old, expensive
At Sacramento’s Department of Utilities office, a careworn wooden tube hangs on the wall, wrapped in old wire. It could be a piece of modern art or an aboriginal didgeridoo. Instead, the redwood cylinder is an artifact of Sacramento’s water infrastructure, and a reminder of a system that has since improved, but along the way has become a frayed patchwork of disparate parts—parts that are increasingly in need of replacement.
Since Sacramento’s early days of wooden pipes and a gravity-based system of water tanks on top of buildings (the first was on I Street), the city’s water mains have evolved into a modern grid of iron, steel and, in some cases, plastic pipes. But this system is rapidly aging, and in response the Department of Utilities is ranking sections most in need of replacement.
“Many of the pipes are aging out and at the end of their useful life,” said Jessica Hess, a spokeswoman for the department, adding that the majority are more than 50 years old.
In Sacramento, however, about 36 percent of the distribution pipes—pipes 12 inches or smaller in diameter that connect to larger ones flowing from water-treatment plants—are 50 to 99 years old, and 8 percent are 100 years old. Of the larger transmission mains, 20 percent are in the 50- to 99-year-old category, and 3 percent are 100 years-old.
“We are looking at replacements by about 2060 to 2070 for many of these pipes,” said Rick Matsuo, a supervising engineer for the Department of Utilities.
For a closer look at a pipe past its prime, Matsuo places a heavy piece of metal on a table in a conference room.
“It looks a like a piece of Swiss cheese,” he said of the riveted steel section of pipe.
Indeed, the section is mottled and full of large holes. This pipe is also representative of some of the water mains scattered throughout the city. Even newer plastic pipes have had a mixed record.
“Even though they are fairly young, the plastic material hasn’t held up as well,” Hess explained.
And in some cases, the water mains have burst. In the most recent instance, this month broken pipes flooded a section of Del Paso Boulevard in north Sacramento (see “Wiped out,” SN&R Beats, July 7). As a result, several businesses and a branch of the Sacramento Public Library have had to temporarily close, and sandbags still line doorways. The city is still determining the exact cause of the flooding.
The Department of Utilities is also at work assessing Sacramento’s 154 miles of transmission pipes and 1,440 miles of distribution pipes.
“A lot of the needed replacements have been in the older downtown core,” Hess said, pointing to a map with a solid blue rectangle highlighting fixed pipes in downtown Sacramento. “It also doesn’t include the sewer [pipe] side of things, which is a different system.”
The map also includes yellow highlights, pointing away from downtown like fingers. The yellow highlights indicate pipes that need to be replaced in the next 30 years.
“This includes pipes made out of plastic, ductile iron and cast iron,” Matsuo said. “And we are trying to determine the materials, [reports] of leaky pipes, criticality and age.”
As part of this assessment process, the Department of Utilities has also ranked pipes most in need of replacement this year and in the near and long-term future. For the 119 miles of 100-year-old distribution mains in need of immediate replacement, the cost is expected to be about $119 million. For the 100-year-old transmission pipes, the cost is expected to be $15 million for 4 miles of pipe.
“It’s going to become much more a topic of discussion, since a big chunk of pipes will soon be past their prime. [Looking ahead], the question becomes: How do we plan for this?” Hess says. “And how do we fund and adjust for infrastructure we need?”