SCH Number 2025081335

Project Info

Title

Temporary Water Transfers from 2026 to 2030

Description

District Background The Butte Water District (BWD) was formed in 1956 and may divert up to 133,200 acre-feet (AF) of water during the defined irrigation season under the terms of a 1969 Agreement on Diversion of Water from the Feather River with the State of California, acting by and through the Department of Water Resources (DWR) and allocated through a 1970 Joint Operating Agreement with Butte Water District, Richvale Irrigation District, Biggs-West Gridley Water District, and Sutter Extension Water District, known collectively as the Joint Water Districts. As a result of these agreements, BWD's water is diverted from the Thermalito Afterbay, part of the Oroville Complex. The 1969 Diversion of Water agreement requires written approval from DWR before any of the districts can transfer water outside the service areas of the Joint Board. An agreement between DWR and the proposed water purchasers to store or transport the water through the State Water Project (SWP) or Central Valley Project (CVP) facilities may also be required to implement a water transfer. Water Transfers The District is preparing for potential one-year water transfers over a five-year period from 2026 through 2030. The transfers may be for environmental enhancement or for one or more buyers with temporary unmet consumptive water demands. Santa Clara Valley Water District (Valley Water) would have the first right of refusal for the water transfers from BWD. A water transfer temporarily moves water from a willing seller (BWD) to an environmental purpose or willing buyer. To make new water available, the seller must take an action to reduce consumptive use, use a substitute water supply such as groundwater, or use water in storage. Additionally, water transfers must comply with all applicable State and federal laws. Moreover, under the 1969 Diversion of Water Agreement with the State of California, BWD’s water entitlement is subject to a drought reduction under certain circumstances related to dry hydrologic conditions. If BWD’s entitlement is curtailed 50 percent for an irrigation season, pursuant to the 1969 Agreement, BWD has not historically participated in a land idling transfer. However, in the event of a lesser reduction, the District may still participate in a land idling transfer. BWD may participate in a groundwater substitution transfer for its lands located in Sutter County under any drought reduction scenario. This EIR analyzes water transfers as if the full amount would be transferred every year during the five-year transfer period; however, transfers may be less frequent and smaller in volume over this period. Annual approval of transfers is required by BWD, the end user, and DWR, regardless of the EIR term or the duration of a water transfer contract. Water Transfer Availability The water transfers would include short-term transfers of up to 24,000 AF in any year. This includes up to 14,000 AF from crop idling transfers and up to 10,000 AF from groundwater substitution transfers. Water made available by crop idling and/or groundwater substitution within the boundaries of the District would be retained and stored by the DWR at Lake Oroville for delivery to Valley Water (or a different buyer if Valley Water refuses, as further discussed below), pending approval from DWR. The Project area, from which the water for the potential transfers would be made available, is defined by the District boundaries, which encompass approximately 32,505 acres in the northern Sacramento Valley in both Butte and Sutter Counties. Land idled for the purpose of the potential transfers would primarily be drawn from the rice acreage within the District. However, those crops suitable for idling as laid out in Table 2-1 of DWR’s DRAFT Technical Information for Preparing Water Transfer Proposals in 2019 within the District would also have the potential to be idled for the sake of transfers. Crop idling acreages for transfers would be to the exclusion of habitat of the Giant Garter Snake. Adjoining areas, other irrigated lands, drains, wetlands, and waterfowl habitat would not be affected, as those areas would receive their normal entitlement, and canals and drains would operate at normal operating capacity. Water would be available on the same pattern during the growing season as it would have been consumed had a crop been planted. Water Transfer Type Cropland idling water transfers make water available by reducing the consumptive use of surface water applied for irrigation. In a groundwater substitution program, groundwater is pumped and used for agricultural purposes in lieu of surface water supplies. The equivalent surface water supplies are then not diverted and are made available for transfer. Groundwater pumping, if applicable, would only occur within that portion of the District boundaries that lie within Sutter County and in a manner consistent with the Groundwater Sustainability Plan (GSP) developed under the Sustainable Groundwater Management Act (SGMA) and would only utilize BWD wells. The District’s proposed water transfers would fully comply with DWR’s DRAFT Technical Information for Preparing Water Transfer Proposals in 2019 where applicable regarding land idling and groundwater substitution transfers as well as monitoring and reporting for groundwater conditions before, during, and after the transfer period. The quantity of transfer water made available through crop idling is currently calculated based on the pattern of Evapotranspiration Rate of Applied Water (ETAW). In the absence of technical information supporting an alternate method, the quantity of transfer water will continue to be calculated based on ETAW for any crop acreage idling. Consistent with the provisions contained in California Water Code Section 1018, potential participating landowners would be encouraged to cultivate or retain non-irrigated cover crops or natural vegetation into their cropland idling transfer to protect habitat value in the area to be idled. In addition, only 20 percent of irrigable acres may be idled under a crop idling water transfers according to DWR’s DRAFT Technical Information for Preparing Water Transfer Proposals in 2019. For the groundwater substitution transfers, the Project would extract up to 10,000 AF of groundwater from BWD production wells. Two existing wells have approximate production capacities of 3,500 gallons per minute (GPM) and 4,000 GPM, respectively. BWD is also in the process of purchasing land for the future installation of a third production well that would also be used if completed within the five-year project duration, which would bring the total water available for transfer from groundwater substitutions to up to 10,000 AF. BWD also owns three groundwater monitoring wells and uses these wells, among others that are not owned by the District (such as those defined in transfer agreements and DWR’s Water Transfer Information Management System, among others), to monitor groundwater levels in the vicinity of the production wells to ensure that no substantial depletion of groundwater supplies occurs as a result of groundwater production. The District has operated these wells in the past at similar production rates and, consistent with extensive monitoring and reporting for such past usage, BWD has not observed any substantial impacts on groundwater levels, groundwater supplies, or to third parties or other environmental resources. Water Transfer Operations No new construction or improvements by BWD, Valley Water or other potential buyers, or DWR would be necessary for the production and transfer of water resulting from the Project. However, the aforementioned third production well could be installed during the five-year Project duration and would likely be used for Project activities if completed. As mentioned above, BWD receives water from Oroville Reservoir under a Diversion Agreement with the State of California. Normal operations involve DWR releasing water from the Oroville Reservoir to the Thermalito Afterbay to be diverted by BWD. For water transfers, DWR reduces what it releases, and, as a result, BWD also reduces its water diversions. Water would be stored in the Oroville Reservoir if capacity is available and stored water follows DWR’s applicable policies and regulations. Storing transfer water could not affect the ability of DWR to meet environmental commitments or water deliveries and would not be possible if flood releases were being made from the Oroville Reservoir as no capacity would be available. Water would become available for transfer on the same schedule that it would have been delivered to BWD. In most cases, this would involve water accruing in storage at the Oroville Reservoir in May and June before being conveyed downstream in July through September. Santa Clara Valley Water District It is anticipated that a key recipient of BWD’s transfer supplies will be Valley Water, who has the first right of refusal of water transfers as a part of the Project. In the event that Valley Water does not elect to receive the transferred water, the District may pursue transfers to the environment or other buyers where BWD can utilize existing water infrastructure to convey transfer water. If both Valley Water and direct conveyance route for the transfer water are not available, BWD may pursue a simultaneous water exchange to convey water to the environment or other buyers. BWD may also transfer water for environmental enhancement, such as for purposes like the Healthy Rivers and Landscapes program if it were to be adopted during the five-year period. Valley Water has contracts for 100,000 AF per year (AFY) of SWP water and 152,500 AFY of CVP water. However, water availability and environmental conditions impact the actual amount of water delivered. As a result, Valley Water receives an average of approximately 170,000 AFY from the two sources combined. During periods of water shortage when contract allocations are low, Valley Water has historically participated in water transfers to secure supplemental water supplies. In addition, Valley Water’s Anderson Reservoir is currently restricted to deadpool due to seismic concerns, which, in turn, takes away substantial drinking water resources for Santa Clara County. The Anderson Dam is presently undergoing a seismic retrofit, but the project is not anticipated to be completed until 2033. As such, Valley Water’s dependence on water transfers is expected to be higher until project completion. Since 1996, Valley Water has participated in a water banking and exchange program with the Semitropic Water Storage District located in Kern County. In wet years, Valley Water stores excess Delta-conveyed water in the Semitropic Groundwater Bank for later use, such as during dry years. To meet current and future demands, Valley Water has also implemented a long-term water conservation program. With a target of saving 100,000 AFY by 2030, the long-term program offers a variety of incentives and rebates that achieve sustainable water savings. The program saved approximately 85,000 AF in 2024.

2 documents in project