One evening while camped at the Clavey Confluence, Jeff mentioned the turbidity of the mainstem water. The dark green that everyone was so used to had turned to a dirty brownish color without me even realizing it. My initial thought was how Jeff must be on this river so much that he can just look out over the river and realize something is wrong. Once I got over the fact that some of the people I was with have been on this river so much that they know it like the back of their hand, I began to wonder what was making the water so turbid. Other people were coming up with their own ideas.
I heard everything from the groover tipped over to a landslide upriver. Every time I came up with an idea though, I would prove myself wrong. The turbidity lasted so long that I knew it couldn’t be anything on a small scale. It would take a huge amount of sediment to turn the Tuolumne brown for nearly an hour. One of the jokes I heard ended up being the closest to the truth: “Bruce must be messing with things.”
A few days later Jeff e-mailed the class explaining the situation. SFPUC (San Francisco Public Utilities Commission) was doing a routine canal flush when a tunnel caved in and muddied the water. Bruce then had to increase the flows coming from Eleanor and Hetch Hetchy Reservoirs to dilute the turbid water which measured at 6 NTU. That extra water meant money lost and money lost means somebody gets in trouble. Fortunately not many people can get Bruce in trouble.