That's because of an arrangement between recreational companies and the Sacramento Municipal Utility District.
SMUD has agreed to release water flows for hydro-electric generation at times when rafters are out on the water, primarily on the weekends.
Scott Armstrong owns All-Outdoors California Whitewater Rafting.
On Capital Public Radio's Insight today, Armstrong said weekday rafting could be a little too calm...
"...There will be water on weekends, there'll be water at good flows. It'll be a little bit less than it has been in the last couple of years. But because of the agreement and because of what SMUD has to release anyway for hydro-power, we will have good recreational flows."
~Scott Armstrong, All-Outdoors California Whitewater Rafting
Armstrong predicts flows will be strongest from mid-June through Labor Day Weekend.
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.'