LA County Water / Energy Nexus Project

by Erin Brewster

In response to the ongoing drought, the Los Angeles County Board of Supervisors directed the County Office of Sustainability (COS) in late 2014 to lead the effort to implement water conservation measures in County facilities and track the results as part of its ongoing green building services program. This effort was given a renewed sense of urgency by the Governor’s April 1st Executive Order and subsequent Water Board emergency regulations aimed at a 25% statewide reduction in potable urban water use. However, tracking and managing water consumption across the County’s entire building portfolio presented several challenges, given the sheer number of facilities and their distribution across more than 110 water service districts in the region. To aid in this effort, COS sought to develop a tool that could easily identify water savings opportunities at County facilities and provide a cost-benefit analysis of potential water conservation projects.

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CivicSpark Member – LA County Office of Sustainability Before and after Images by Peter Kim

The water conservation program developed by COS targeted the three largest end uses of water in office buildings as identified by the EPA: plumbing fixtures, heating/cooling, and landscape irrigation. The scope of potential water conservation projects included in the Countywide analysis were replacing older plumbing fixtures with more efficient devices, installing advanced water treatment systems in cooling towers to allow for an increase the number of cycles of concentration, and replacing ornamental turf with drought-tolerant landscaping. In addition, COS continued to assist facilities with custom water conservation projects on a case-by-case basis. To track water conservation progress, COS compiled 3 years of water consumption data for County utility accounts and calculated a baseline level of water use for each facility to compare against future consumption.

The water savings calculator developed by COS with the aid of the CivicSpark program uses data collected from facility managers to provide a comprehensive cost-benefit analysis of potential water conservation projects in the three target areas. Data was collected for each water supplier that serves L.A. County facilities, including the current quantity rate for water, the water sources and their associated energy intensity, and local evapotranspiration rates. The estimated water savings and associated co-benefits were then calculated using a variety of methodologies. For plumbing fixtures, the estimated savings are based on an adaptation of the U.S. Green Building Council’s Indoor Water Use Reduction Calculator for the LEED rating system. For cooling towers, the size of the cooling tower and cycles of concentration in the pre- and post-upgrade cases are used to estimate water savings. For landscape projects, the water savings calculator uses local evapotranspiration rates to compare the water needs of turfgrass to drought-tolerant landscaping using the methodology outlined in “A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California” (California Department of Water Resources, 2000). The resulting analysis allows County departments to prioritize potential water conservation projects based on their needs (saving the most water, meeting GHG reduction targets, shortest payback time, etc.), and identifies where the county can achieve the greatest savings for its investment.

Development of this tool revealed several challenges to implementing this type of conservation program at the regional level, mostly due to the fragmented nature of the water supplier landscape in California. Data collection was hampered by the lack of a central, statewide repository for much of the necessary data (including current water rates). Additionally, the structure of local government can pose challenges to effective management of water use, as billing and consumption data is generally not received by the end users or facilities, but instead processed by financial offices at the department level. The Governor’s April 1st Executive Order created additional complications, as the Water Board’s emergency regulations delegated responsibility for compliance strategies to the water district level, resulting in 110 different sets of water use regulations at the customer level that affect various County facilities. Customer-level regulation can be difficult to track and manage for regional government entities overseeing a utility billing portfolio that can include thousands of accounts across multiple water service districts.

Despite the challenges encountered, COS has begun to develop a framework that will allow L.A. County to more effectively manage its conservation efforts and track its water use beyond the current drought. The water savings calculator has streamlined the process for assessing water conservation projects, and COS continues to refine this tool as it is applied to County projects. Meeting the County’s water conservation goals and complying with the emergency water use restrictions may require significant changes to the way the County has tracked and managed its water use, but the result will be a more flexible system that will allow Los Angeles County to adapt to a changing climate.