The release of water from Friant Dam for the SJRRP depends upon the amount of runoff. Using water supply forecasts for the Friant Division of the Central Valley Project, the SJRRP uses the estimated total unimpaired inflow below Friant Dam to determine an allocation. The Restoration Administrator makes recommendations on the timing of releases based on river conditions and the specific goals and objectives at that time. Prior to an increase in flow rates, the SJRRP analyzes the likely effects on the river and surrounding lands and documents the results with a Flow Bench Evaluation. Following an affirmative evaluation, the SJRRP issues a notification and changes the releases.
Exceedance forecasts use snowpack measurements to determine future runoff.
Monthly water supply forecasts report unimpaired inflow values in terms of the percent exceedance, 10%, 50%, and 90%. The South Central California Area Office of Reclamation provides a best estimate for the purpose of developing delivery schedules. More information may be found here. Forecasts include:
The SJRRP conducts Flow Bench Evaluations prior to deciding on an increase in flow target. These consider channel conveyance limitations, operations call concerns, seepage hotline concerns, real-time and manually measured groundwater levels and their relation to thresholds, as well as seepage predictions.