Weight Loss Question...?

1.) If i dont eat 1500 calories per day my body will go into "Starvation mode" and begin to not burn calories but conserve.... Is this true? Or would i actually lose weight if i cut my caloric intake? 2.) Drinking only water helps as well... If i drink water to death will this help? How much weight can i figure to lose on a weekly level if i keep my caloric intake below 1500 and not do exercise? Will i lose weight?