SACRAMENTO, Calif. - The Egyptians did it. So did the Romans. Now, at the Presidio of Monterey in California, the U.S. Army Corps of Engineers Sacramento District is using the same ancient practice to meet modern-day, green-building requirements.
The district is harvesting rain water and storing it in large, underground cisterns for future use at a new school building under construction at the installation.
"Monterey has forever been in a drought situation and water is a premium down there," said Alan Morita, with the Sacramento District's design branch.
"In using rain water - water that would have been going down the hill...and flushed out to the ocean - we've actually cultivated that water and used it for functional purposes," said Morita.
According to the Presidio energy manager, Jay Tulley, "The cisterns are one piece of our overall water conservation strategy. It's another step towards the Presidio's goal of reducing potable water usage by two percent per year."
The new general instruction building, designed to achieve Leadership in Energy and Environmental Design certification, is for use by the Defense Language Institute, the primary center for foreign language instruction by the Department of Defense. The project, named GIB11, is the final of three general instruction buildings the Sacramento District has built for the installation.
Three cisterns will be used for the project: two 20,000-gallon tanks and one 35,000-gallon tank. The dual 20,000-gallon tanks will collect rain water from the parking lots surrounding the building to supply an irrigation system. The 35,000 gallon tank will collect water from the roof of the building to supply the building's toilets via a non-potable water piping system.
"We're getting our water from the roofs," said Morita, "and, on demand, we are using that to flush the toilets - it's a non-drinking source of water."
The bulk of non-potable water will be used for flushing, and the rain water system will help meet 80 to 85 percent of that demand according to Morita.
The cisterns were placed at the site in April 2013 and are expected to be fully operational by the time construction of GIB11 is complete in late 2014. The cisterns will also be able to support the neighboring GIB09 building, a similar project completed by the district in 2012.
"GIB09, already completed, requires now only the hookup of the tank, which is already on site," said Morita.
Achieving LEED certification for both buildings required a high level of collaboration between the Sacramento District interdisciplinary team that designed them, according to Morita.
"All disciplines have to work together to achieve LEED certification," said Morita. "We all had a part in achieving the recognition of LEED-Silver for GIB09. And we all, as a team, are working to achieve the LEED-Silver for GIB11."