The Sacramento Bee reports state and federal wildlife officials have announced a plan to move hatchery-raised salmon by tanker trucks should the river and its tributaries prove inhospitable for the fish.
Officials fear the rivers could become too shallow and warm to sustain salmon trying to migrate on their own.
They're keeping an eye on conditions and will be ready to implement the plan next month, barring heavy rains.
Salmon from the Coleman National Fish Hatchery on Battle Creek, a tributary of the Sacramento River, are usually released in April and May.
The trucking plan is similar to one carried out in the drought of 1991-92.
The drought intensified over the last week in the Western U.S. as the region swelters under a heatwave and firefighters battle major wildfires.
Dangerous fire weather conditions has prompted one federal agency to impose fire restrictions on public lands in northern California.
Mandatory statewide water conservation rules have ended in California. But Sacramento-area users conserved 22 percent in June, compared to June 2013.
California and federal agencies say a new strategy is needed to save the endangered Delta smelt.
California is in the fifth consecutive year of drought, but state water managers ended mandatory conservation rules. Local water suppliers now determine conservation rates, and some have low or no targets. A water expert says that's 'shortsighted.'