Flows between 150 and 300 cfs are considered reasonable for novice canoeists. More experienced paddlers who have previously paddled the river should find it enjoyable up to 1,000 cfs. Levels above 1,000 cfs should be left for strong paddlers with sufficient whitewater experience to deal with the hazards of fast, powerful and turbulent currents. In addition, during high flows the river spreads out and runs through all the trees and brush that are normally on dry ground. Paddlers mush have the skill to choose the safest routes, and to avoid the trees they will inevitably encounter.
Since 1995, minimum instream flows are at least 50 - 250 cfs in the summer time and at least 100 - 300 cfs in the fall and winter, depending on whether it has been a dry or wet year. These flows are due to the efforts of the Tuolumne River Trust and Dept of Fish & Game. Prior to that, minimum flows appear to have dropped as low as 13 cfs. See: Monthly average flows from 1985 to 2005.
Peak flows are usually in the winter or spring and generally range from 1,500 cfs up to 4,000 or even 10,000 cfls. The January 1997 floods peaked at 58,000 cfs. In some dry years the peak has occurred in October, ranging from 690 cfs up to 2,630 cfs.
Most of the flow of the Tuolumne river is diverted at La Grange dam for irrigation use by Turlock Irrigation District and by
Modesto Irrigation District.
Real time rain and temperature information is available from some nearby weather stations;
Green Springs station
and near Snelling