The North Valley Regional Recycled Water Program (NVRRWP) is a collaborative partnership that includes the Cities of Modesto, Turlock, Ceres, the Del Puerto Water District, and Stanislaus County. The proposed Recycled Water Program is being developed as a regional solution to address south of the Delta water supply shortages and reliability concerns by utilizing recycled water for beneficial use. The proposed NVRRWP would deliver recycled water produced by the Cities of Modesto, Turlock, and Ceres to the Del Puerto Water District (DPWD), a Central Valley Project (CVP) agricultural water district located primarily in western Stanislaus County, who will in turn provide a share to neighboring CVPIA-designated wildlife refuges.
Key Issues
Located in western San Joaquin, Stanislaus, and Merced Counties, DPWD parallels and delivers water directly from the Delta-Mendota Canal (DMC) to 45,000 acres of productive farmland between Vernalis on the north and Santa Nella to the south. As a CVP Ag service contractor located south of the Sacramento-San Joaquin Delta, DPWD has experienced significant shortages and decreased reliability in the quantity of water it receives annually under the terms of its federal water service contract. Over the past seven years, DPWD has received an average of only 20% of its full contract supply and, in 2014 & 2015, received none at all. DPWD’s current year 2016 supply is just 5% of its full contract amount, totaling approximately 7,011 AFY, far short of the irrigation needs of DPWD’s growers.
Because DPWD does not have an alternative water supply, except for limited privately developed groundwater supplies, shortages in CVP deliveries result in serious economic hardship, not only on DPWD growers but on the region in general. To address this situation, the NVRRWP is looking to utilize available recycled water to augment existing supplies and provide a more reliable supply of irrigation water to the region.
Concurrent with DPWD’s ongoing CVP shortages, the Cities of Turlock and Modesto are facing more restrictive regulatory requirements for wastewater discharges to the San Joaquin River. Both Cities have constructed tertiary treatment facilities to comply with more stringent National Pollutant Discharge Elimination System (NPDES) permits. The tertiary facilities not only provide NPDES compliance, they create a valuable water resource – recycled water – which can be applied for beneficial use in local region. While the future likely holds even stricter limits on the Cities’ treated wastewater discharges to the San Joaquin River, there are no significant impacts to River flows associated with the removal of these discharges.
Solution
Recycled water produced by the City of Modesto and Turlock (treated to meet California Department of Public Health Title 22 standards for unrestricted non-potable use) will be conveyed via direct pipeline to the Delta-Mendota Canal (DMC), where it will be used by DPWD farmers.
The NVRRWP will supply a highly reliable source of supply which could meet up to 1/3 of DPWD’s needs in the future.
The Delta-Mendota Canal as a means of conveyance and delivery has shown itself as the most cost effective while at the same time providing the greatest number of benefits. Utilizing the DMC not only provides for the delivery of much-needed irrigation water to local agriculture but, during the non-irrigation season, also provides for the temporary storage of the water for later delivery and allows for the provision of water supply benefits to the refuges, and thus the environment.
