California Department of Fish and Wildlife

Temperature and Flow Criteria for Planting Catchable Trout

Catchable trout shall not be stocked in streams when water temperatures reach 75°F and it appears that such temperatures will continue to occur regularly, or when stream flows drop below 10 cfs. The exception is that suitable streams with flows between 2 and 10 cfs may be planted if water temperatures do not exceed 70°F and other conditions are satisfactory. Stocking shall be discontinued if conditions are unsuitable because of shallow water, lack of pools, growth of algae, poor water quality, or other reasons

Catchable trout shall not be stocked in lakes or reservoirs after surface water temperatures reach 78°F and it appears that such temperatures will continue to occur regularly, nor after a trout die-off is attributed in whole or in part to an oxygen deficiency. Stocking shall be discontinued if algae blooms, aquatic weed growth, high turbidity, high alkalinity, or other conditions render the lake unsuitable for catchable trout or for fishing.

Catchable trout shall not be stocked in lakes or reservoirs until water temperatures reach 42°F or higher most afternoons, or in streams until water temperatures reach 45°F or higher most afternoons. Catchable trout stocking may be suspended in reservoirs during periods of spill in order to avoid losses of planted fish to downstream areas where the trout may not be readily available to anglers.