Purpose & Need
Windsor’s Recycled Water Challenge
The Windsor Golf Course is irrigated with recycled water
Currently, the Town uses much of its highly treated recycled water to irrigate public and private lands. In dry weather months, the Town of Windsor receives an average of 1.6 MGD of wastewater at its Water Reclamation Treatment Plant (WRTP). At this 74-acre facility the water is treated to advanced (tertiary) standards, disinfected and then sent to storage ponds.
Two of the recycled water storage ponds are located on the WRTP site and three are located at the Windsor Golf Course. The system’s existing storage capacity for tertiary treated water is 165 million gallons (MG).
During summer, the stored recycled water is used to irrigate approximately 538 equivalent acres of public and private land, including the local golf course, pasture land, vineyards, orchards and urban landscaping (i.e. athletic fields, parks and residential landscaping). An equivalent acre is an acre of land that uses 30 inches of irrigation water per year.
During wet-weather months (October through May) when rainfall contributes additional water to the system and irrigation is unnecessary, the recycled water produced can exceed the Town’s capacity to store and discharge it.
During this time, the excess water is discharged into Mark West Creek. These discharges must be in compliance with seasonal limitations established under the Town’s existing National Pollution Discharge Elimination System (NPDES) Permit, which allows a maximum daily rate of one percent of the natural stream flow.
Due to unpredictable weather, the storage, irrigation and creek discharge options are not sufficient, thus straining the recycled water system. And, future flows to the WRTP are expected to increase, further straining the system.
Taking advantage of the opportunity to tap into Santa Rosa's Geysers Recharge Project provides the Town with another discharge option and ensures continued compliance with its discharge permit.
Managing the New System
Connecting to the Geysers Recharge Project will impact how the Town manages its recycled water storage and discharge operations. Recycled water irrigation operations may also be impacted because, in summer months, less recycled water may be available.
Currently, the Town of Windsor provides recycled water for a variety of irrigation purposes. The Town’s agricultural customers include Gallo Vineyards, Santa Rosa Junior College’s Shone Farm and other growers in the Windsor area. Urban users include Windsor High School, the Vintage Greens neighborhood, the Windsor Golf Course and some parks.
The Town recognizes and appreciates the important role its customers play in the success of the recycled water system. By using recycled water to irrigate their landscapes, land and crops, these customers have helped the Town remain in compliance with its permits and have reduced the need for the Town to build additional and expensive storage.
Factors impacting summertime irrigation include weather, available Town storage, available storage from other agencies and the amount of recycled water pumped to the Geysers during the irrigation season. The exact impact to a given customer's recycled water deliveries is not known and may even be extended by a few years because of variable factors. The Town will be meeting with its customers in the coming months to work out an approach to maintain reliable and equitable recycled water service.
As part of the strategy to ensure a reliable supply, the Town’s agricultural parcels will continue to receive recycled water for “discretionary” irrigation. This means that, during summer months when there might not be enough recycled water to meet all users’ needs, the Town will not irrigate their own parcels and will instead provide that water to its customers.