Install a low-flow shower head, which restricts the water ouput to no more than 2.5 gallons per minute. The shower heads are inexpensive and screw into existing fittings. If you live in an older home and haven’t renovated your bathroom, the shower head may be using as much as 5.5 gallons per minute. To determine how much water runs through your shower head, put a bucket under the nozzle and time how many seconds the water takes to get to the one gallon mark. If it’s less than 20 seconds, you may want to investigate the low flow shower head options available.