SCH Number 2021120653

Project Info

Title

Dudley Ridge Water District and San Gabriel Valley Municipal Water District Water Transfer and Banking Program

Description

The DRWD-SGVMWD transfer program, which began in 1995 and has been modified through its existence, has allowed DRWD to convey excess water supplies in a given year to SGVMWD when SGVMWD has the capacity to receive the water. Capacity is determined by the California Aqueduct capacity, water levels of the Main Basin in the SGVMWD, and flood control restrictions affecting SGVMWD’s ability to recharge water. SGVMWD maintains an accounting of the DRWD water received, and when DRWD requests a transfer from SGVMWD for up to 90% of the water previously conveyed to SGVMWD, SGVMWD transfers a portion of its current year Table A water to the extent it can meet DRWD’s request. This arrangement allows SGVMWD to receive additional water that it can recharge earlier than it otherwise could, and nets 10% of the DRWD water delivered to supplement SGVMWD’s groundwater account in the Main Basin. In return, DRWD can better regulate its variable SWP supply year by year. The return of water is available to DRWD once SGVMWD has received 5,000 AF of its SWP supply, approximately 17% of its Table A allocation. The 2020 Agreement also allows for DRWD have a portion of their previously transferred water to SGVMWD delivered to DRWD by requesting DWR to reclassify a portion of SGVMWD’s SWP previously water delivered in a given year to SGVMWD to be shown as delivered to DRWD. Water delivered to SGVMWD by this reclassification is limited to years where the SWP Table A allocation is 50% or greater. The 2020 Water Banking Agreement allows SGVMWD to store water within the KWB capacity for interim storage during times when SGVMWD’s conveyance capacity in the East Branch of the California Aqueduct is limiting deliveries to SGVMWD. It is expected that SGVMWD would generally bank some of its Table A water in the KWB in years where there is 70% SWP water allocation or greater. Banking the water during higher allocation years allows SGVMWD to avoid the risk of carryover water spilling from San Luis Reservoir when SGVMWD’s delivery capacity is limited to a rate lower than its contract capacity of 48 cubic feet per second in the East Branch. Except for the system and administrative losses of 10-15%, the intent of the 2020 Agreement is for DRWD and SGVMWD to each receive the same amount of SWP water with or without the transfers, however, the timing of the transfers will be different to allow each district to better regulate, through storage, the SWP water in a manner that provides each district greater reliability.

4 documents in project