Rivers in California are flowing fast and wide this year as record snowpack in the mountains melt. All that water has created flood damage and worries about more to come, but one industry is thriving after years of drought and shrinking rivers -- whitewater rafting.   Reporter: Joshua Yeager, KVPRCalifornia workplace health and safety regulators are holding a public hearing on Thursday on a proposed rule to prevent heat-related illness in indoor spaces.Reporter: Farida Jhabvala Romero, KQED  Learn more about your ad choices. Visit megaphone.fm/adchoices