Cal Poly San Luis Obispo Drought Response Program

A diverse group of campus leaders at Cal Poly San Louis Obispo met in 2014 to develop a response to the California drought that had persisted for over four years, seriously depleting water reserves statewide. The team’s conservation response was driven in part by the governor’s January 2014 declaration of a statewide water emergency, and the passage of an expanded CSU Sustainability Policy in May, mandating water reductions of 10 percent by 2016.

The drought response team identified major areas for conservation — in buildings, in landscape irrigation, and in agricultural programs. A national water-engineering consultant, Watersavers, LLC, was contracted to conduct detailed site audits and to report on water optimization opportunities, and consultants from PG&E’s Food Service Technology Center documented water conservation opportunities in the main dining facility.

A diverse team of campus and community leaders worked with consultants to identify cost effective water conservation measures, reducing annual water use by 11 percent, with many measures having a simple payback of less than a year.

The first set of water conservation measures were immediately implemented using existing operations and maintenance budgets. These included the retrofit of nearly 1,000 lavatory faucets with 0.5 gallon per minute (GPM) aerators, replacing 300 showerheads in residence halls with 1.5 GMP devices, replacing four cooking steamers with more efficient products, and switching to a high efficiency spray nozzle in one walk-in cooler. The project also included the reduction of cooling tower “blow-down” at the central plant (done to flush minerals from the system), and reinstituting the use of pool covers at the Anderson Aquatic Center. Together these measures are saving 18.5 acre-feet of water per year, equal to 6.9% of all building water use. The projects had a total cost of $74,000, producing utility savings of $88,000 annually, and an impressive simple payback of less than a year.

Campus water use from 2003 to 2014 (acre-feet per year) shows significant reductions in 2013 and 2014.

Two additional conservation measures were funded through the CSU Office of the Chancellor’s 2014-15 Energy and Water Conservation Program, and were completed in summer and fall of 2105. These included the retrofit or replacement of water efficient toilets and urinals (1.28 and 0.125 gallons per flush, respectively) that will save 9 acre-feet of water annually, equal to 3.4% of the campus’s building water use, and saving $44,000 annually. A landscape irrigation control system from Calsense was also installed as part of this work, with sensors that monitor irrigation needs and a wireless communication network. The new irrigation control provides substantial savings, estimated at 25 acre-feet of water per year, equal to seven percent of total landscape irrigation water use. These savings will be enhanced by expanded mulching practices on campus, using certified organic compost from campus agricultural operations and landscape waste. Through improved water retention, the mulching practices will save 13 acre-feet per year. Combined, all these measures reduce total landscape irrigation by 11 percent.

Reduction of turf areas, irrigation control and mulching are contributing to landscape water savings of 11 percent.

The agricultural land at Cal Poly provides unique water conservation opportunities, and Agricultural Operations (Ag Ops) staff identified many changes to improve irrigation efficiency. At many locations sprinkler heads were replaced with 1/8-inch nozzles, resulting in a 33-percent drop in water use across 120 acres of irrigated pasture and row crops. In addition, micro-emitters were installed to irrigate all orchard crops. These Ag Ops measures have led to annual water savings of 55 acre-feet, or close to 18 million gallons.

These successful outcomes resulted from having participation from a diverse set of team members from both the campus and the surrounding community. By engaging expert auditing consultants, the project team was able to quickly devise and implement its successful drought response plan. Together the completed measures are saving a total of 120 acre-feet of water per year (39 million gallons), equal to 11 percent of the previous campus benchmark, meeting its goal a year ahead of schedule and yielding a simple payback on investment of only 2.8 years.

Main image of Whale Rock Reservoir from Wikipedia.