Reducing Reliance On Imported Water, One Home At A Time: Yucaipa Valley Water District's Dual-Plumbed Community

The Yucaipa Valley Water District (District) is a medium-sized water district located in an arid area of Southern California. To diversify the District's water resource portfolio and reduce reliance on potable water sources, the District has implemented a series of programs to increase recycled water use. One of them is serving recycled water to Summerwind Trails: the region's first front and backyard dual-plumbed community. Implementing and maintaining the program has illuminated numerous benefits and challenges. The District serves portions of the cities of Calimesa and Yucaipa, located in Riverside and San Bernardino Counties, California. The District has about 13,800 potable water service connections, 700 recycled water service connections, and 14,100 sewer service connections. Potable water sources include local groundwater resources, imported water from the State Water Project, and minimal surface water resources. The District has served recycled water for the irrigation of meridians, golf courses, and parks since 2009 and in 2018 the Board of Directors of the Yucaipa Valley Water District approved the 'Rules and Regulations for Recycled Water Use and Distribution' which outlines policies for residential recycled water use within the District.
The recycled water system is mainly fed from the District's Wochholz Regional Water Recycling Facility (WRWRF) but can be supplemented with untreated imported water or microfiltration backwash from the District's drinking water facility. The WRWRF treats an average of 3.7 mgd of wastewater and produces 3,800AFY of recycled water. The facility produces partial Reverse Osmosis treated and fully disinfected tertiary treated water. The Summerwind Trails community is a new development located in Calimesa, California. The first phase of building is complete and includes approximately 600 homes and an elementary school. To make this project possible, the District has increased the investment into the recycled distribution system. The Summerwind Trails recycled system is temporarily being fed with potable water until the completion of the Calimesa Recycled Water Conveyance Project, a 24 inch 2.2 mile pipeline, which is the last infrastructure required to incorporate Summerwind Trails into the District's recycled water distribution system. Recycled pipelines within the community were installed during development along with recycled water meters and backflow prevention devices for every home.
The Summerwind Trails community is part of a Homeowners Association; the HOA works closely with District staff to help the homeowners through the required steps for training and backyard installation. As required by Title 17 of the California Code of Regulations, a homeowner from each property is required to attend a Site Supervisor Training. The training includes an overview of the recycled water treatment process, design requirements, and the process homeowners must go through to install their backyards. After the training is complete, homeowners create their backyard plans and submit them for review. Once District staff approve the plans, homeowners may begin work to install their backyards. Prior to burying irrigation lines, homeowners must notify district staff so that the lines can be inspected for compliance and be GPSed. Staff perform a final inspection after the installation is complete and schedule backflow and cross-connection testing as required. The homes of Summerwind Trails consume significantly less potable water than other homes served by the District. A home in Summerwind Trails typically uses 4 thousand gallons of potable water per month and between 3 and 9 thousand gallons of recycled water per month. Because there are two meters associated with each home, it is possible to distinguish indoor and outdoor water use. Throughout the year an average of 35% of water used is potable water, implying that about 35% of water is used indoor. Indoor use may be slightly less due to potable water used for pools and outdoor water features. This data can inform water conservation programs and narrow down the location of residential leaks.
This project also has some unintended consequences. For example, in the summer of 2021 community members noticed that there was no cold water coming out of the taps. Because so little potable water was being used, the water was heating inside of the pipelines in the streets. This is usually typical of a desert community water system. Although the outreach efforts to the hundreds of residents in Summerwind Trails has been challenging for District staff, training each homeowner about the rules and responsibilities of recycled water use has allowed the District to operate sustainably while the population increases. The successes of the Summerwind Trails community has encouraged the District to continue the development of dual plumbed communities. The District's second dual-plumbed community, Serrano Lake, went online in early 2022. Yucaipa Valley Water District's dual plumbed communities provides water sustainability for the region which is crucial at a time when water supply reliability is unpredictable in this current climate.