No one water drop wastes itself. Wherever you put or whatever you use it for . (Water Cycle)
But you may need energy for water treatment, because of the pollution (atmosphere, springs, rivers) that waste it along the track made before you can use it . Pollution acts like someone that use water before you can get it. So what you get is not what you could.
Wasted water needs another round in the cycle (and a clean return path) or energy to be used to make it accettable for any use.
Yes saving water saves energy!
6.5% of the energy used in the state of California is for pumping and treating water - in fact, pumping water south (and uphill) in the State Water Project accounts for 2-3% of all the electricity used in the state. If we can reduce our consumption of water, less amount of energy would be required for pumping and treating water. Small measures like fixing leaking faucets and sprinklers can also go a long way in saving water. For more water saving tips, check out the link below.