Robert, the current issue with Folsom Lake is that in order to obtain the level of flood protection they want, they have to wait until the lake rises to the gates to even begin letting water out. If the gates were lower, the level of protection could increase considerably since anticipated flows from heavy rains or snow melt could be released much earlier. The American River can sustain flows of 115,000 CFS indefinitely, after that, the levees become vulnerable. In 1986, the flows exceeded 135,000 CFS which was causing boils or seepage under the levee system. After 160,000 CFS, its going to breach the levees. It is now being said that if we loose control of the American River, the monetary damage could be expected to exceed that of New Orleans in terms of real estate destroyed. It has been an eye opener all over again for this area or at least Sacramento and those cities to the North and South. Like New Orleans, Sacramento pumps its storm water. In the downtown area, several banks of pumps with 1000HP electric motors sitting side by side 10 long move massive amounts of water. I do not know if they have secondary electric backup. Fortunately since 1986, the slurry wall has been implemented on much of the levee system. Did you ever see the excavators used to cut the trench down the levees? The boom and dipper must have been 70' long. Rat...
PS, the picture shows how a full Folsom Lake broke open a radial arm gate which caused world wide concern since many dams use gates like this. It took several days for the lake to lower to the level of the bottom of the gate. Even at that, the lake still had lots of water.
