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Functional flow components:
(Blocks on above graph are approximate.)

[Base Flows] Baseflows released from Lewiston Dam to the Trinity River are currently 450cfs through the summer, shifting to 300cfs from about Oct 15 through the subsequent spring.

[Synchronized Storm Pulse] A release synchronized to a storm event is possible Dec 15 to Feb 15. This is triggered by a CNRFC forecast for the Trinity River above North Fork that rises to 4500cfs or more. Once triggered, the release may continue even if forecast is reduced. Maximum daily average flow release is capped at 6,500 cfs and storm conditions will be monitored to avoid exceeding the TRRP Maximum Fishery Flow levels (see map of modeled inundation per 2016 topography). The primary purpose is to generate geomorphic change in sync with a natural storm event.

[Seasonal Flood] Depending on forecast water year type in the CDWR February B120 forecast and whether or not a synchronized flow has occurred, TRRP may schedule flows above baseflow in the Feb. 15 to Apr. 15 timeframe. Depending on the March B120 forecast, the schedule may be adjusted as of March 15. The primary purpose of this is to inundate floodplains similar to natural wet-season flooding.

[Snowmelt Peak and Recession] The CDWR April B120 forecast determines total volume volume of restoration flow releases. Water that has not been released for a Synchronized Storm Pulse or Seasonal Flooding is scheduled for release during the Snowmelt Peak and Recession period. This schedule encompasses many purposes for river ecology and the salmonid life cycle.

All TRRP Environmental Flow hydrographs above baseflow will be added to this graph (red line) expediently as they are scheduled. B120 forecasts are released about the 10th of February, March, and April. Details of these flow actions are described on our Variable Winter Flows page and in the associated EA.