As the water gets shallower at Folsom Lake, the boats must go slower really slow. Which is not great news for motorboaters, Jet Ski riders and water skiers. Vadim Manzyk, 15, left, and his cousin Alex Repetukha, 7, of Sacramento fish at Oak Beach on Folsom Lake on Monday. State park officials may set a 5 mph speed limit for boats because water levels are getting so low, a problem for water skiers and others who need speed on the water. ...