Installing low-flow showerheads and faucet aerators is the single most effective water savings action you can make for your home.
For around $30 and an hour’s time you can install both and cut home water use at least 10%. At 5,000 gallons per month, that adds up to 6,000 gallons over one year, at least $30 for the water; plus, you’ll save the cost of heating it.
A low-flow faucet runs less than 2.75 gallons per minute and showerheads should run at 2.5 gallons per minute (or take longer than 12 seconds to fill a two-quart container, if you want to test yourself); check your current units (it’s typically engraved around the barrel) for flow specifications.
The EPA WaterSense program labels showerheads efficient if they use a maximum 2.0 gallons per minute.
Also consider replacing your toilet with a Water Sense product for less than $100. Replacing an older toilet that uses 3.5 gallons per flush (gpf) with a high-efficiency version that uses 1.28 gallons will save about 13 gallons per day, nearly 5,000 gallons per year (assuming six flushes per day). Some older toilets use as much as 7 gallons per flush.