Nestled on a plot of land in Los Altos Hills with a picturesque view of San Francisco Bay, the 3-million-gallon Neary No. 2 Tank – the size of a football field and approximately 6 feet high – sits empty in anticipation of seismic retrofits.
As part of the $2.7 million Neary Tank Utilization Project, the Purissima Hills Water District and the Los Altos Hills County Fire District are upgrading infrastructure and preparing the community for emergencies – including the possibility of a catastrophic earthquake. Although the town’s current water storage capacity and pressure have been deemed adequate for day-to-day use, building codes and emergency preparedness needs have changed significantly since the town’s first tank, Neary No. 1, was installed in the 1960s.
“We’ll have the bandwidth to move water faster and more efficiently,” said Patrick Walter, Purissima Hills Water District general manager, of the Neary Tank project. “It’s designed to be here after an earthquake.”
Beginning last fall, the district placed 7,700 linear feet of 12-inch ductile iron pipe beneath Altamont Road, Byrne Park Lane and Moody Road to connect the tanks at Neary to the Altamont Tank. According to Walter, the new pipes will increase the fire flow, or amount and pressure of water that flows to hydrants located in Los Altos Hills.
Although residents and cyclists experienced some disruptions while crews dug trenches and placed earthquake-proof pipes underground, Purissima Hills engineer Joubin Pakpour said the first phase of the project is nearing completion – approximately two months ahead of schedule – with few complaints from neighbors. After the pipes are tested, the streets will be resurfaced to conceal the trench work.
On-site work to retrofit the Neary No. 2 Tank was scheduled to begin last week. A crew will install an exterior foundation and seismically retrofit roof rafters and columns, according to Pakpour.
“Once the project is done, the storage in Neary represents approximately four to five days of emergency water usage by our customers after a catastrophic event,” he said of the tank’s storage capacity of up to 1 million gallons in the winter and 2 million in the summer. “This assumes our customers will turn off their irrigation after a large-scale earthquake and use the water for emergencies only.”
Pakpour added that the tank would have a seismic valve that can be operated remotely prior to an earthquake.
“This valve senses an earthquake approaching – typically by about 10 to 30 seconds, depending on the epicenter of the earthquake – and automatically starts to close the valve,” he said. “This way the water is preserved in the tank for post-earthquake emergency usage.”
When the storage capacity of the Neary No. 2 Tank is combined with the district’s nine other tanks, the district will be able to store approximately as much emergency water in Los Altos Hills as is stored in Palo Alto. The increase in available water flows in the area should improve water quality and fire protection capabilities, in addition to upgrading the aging distribution system.
For more information, visit purissimawater.org/constructionprojects.html.
Neary Tank Utilization Project - Photos by Ellie Van Houtte/Town Crier