Check for Leaks
You can do a water meter test for leaks. Leaks can waste a great deal of water and can increase your water bill. To check for a leak in your home, turn off all the water fixtures, and then check the water meter. Note the reading on the water meter and wait for 20 minutes to a half hour and check the meter again. If the dials or the numbers on your meter have changed, you have a leak.
Do a Water Audit
Check your showerheads and faucets to see if you should replace them with low-flow models or aerators.
Either adjust the float in your toilet tank by gently bending the arm down or adjusting the screw so it turns off sooner.
Check your laundry and dishwasher habits. Don't run your dishwasher unless it is full. Try to save laundry up for a full load, and always select the correct water level for each load.
Check your yard sprinkling system to make sure it comes on in the early morning or in the evening so that you lose less of the water to evaporation.
Always sweep your driveway and sidewalks instead of using your hose.
Check your landscaping. A yard varied with shrubs and flowers instead of all grass will use less water, and will add beauty to your home.
Repair or Replace Older Toilets
Toilets account for almost 30% of the water we use in our homes. Toilets installed before 1994 use 3.5 to 7 gallons of water per flush, and as much as 20 gallons per person per day. And to make matters worse, 20% of all toilets leak. By replacing an old toilet with a new high efficient one, that uses only 1.28 gallons per flush, the average home can save 7,000 to 93,000 gallons of water per year.
If you can't replace the toilet right away, install a "dam" in the tank so that a part of the tank can't fill with water. You can buy them at most hardware stores or you can make on yourself. Just fill an empty soda pop bottle or a half-gallon size plastic milk carton with water and set them inside the toilet tank where they won't interfere with the any moving parts. This will displace that much water from the tank and keep it from flushing down the drain.
At least 20% of all toilets leak and you should check yours every two to three months. The San Bernardino Municipal Water Department has free leak detectors you can use to see if you toilet leaks. Just drop the two leak detector tablets in the tank, and then watch the bowl without flushing. If any of the colored dye shows up in the bowl, you have a leak at the flapper that can be costing you money and wasting water. You can get new flappers at the local hardware store and install it yourself, or you can call a plumber to fix the toilet.