Conserve and Preserve the Water Quality

Conserving water is easy! Not only will it help the environment, but it will probably save you money as well.

Steps

Use non-toxic, phosphate free, biodegradable dish detergent.
Stack and run a full dishwasher.
Wash dishes by hand and use the sink to both wash and rinse dishes. Try not to rinse dishes under running water. Rinse them in a separate sink of water.

Use nontoxic, biodegradable soaps and toiletries made from vegetable oils and natural ingredients. Remember that all toiletries end up in the water supply.
Install low flow shower heads (these can be very affordable) and low flow toilets (a long-term investment).
Shower instead of taking baths. Turn the shower off when soaping down or washing hair. Turn the shower on to rinse.
When brushing your teeth, run water only to rinse the brush, and turn the water off while brushing.
Check leaky toilets and sinks. One way to do this is to drop a bit of food coloring into the water tank. If the color shows up in the toilet bowl without you having flushed first, your toilet has a leak.
See Clean-a-Bathroom-Using-Natural-Products

Mulch plants to promote water retention. Specially with the local plants, they are much more used to the weather conditions.
Try to use less or avoid turf grass, it requires much water.
Install drip watering systems.
Do not water during the hottest part of the day. Water during the cooler part of the day to prevent evaporation. It may be early in the morning or at night.
Plant low water use plants. Learn Xeriscaping.
Plant Trees. They reduce soil and air temperature.
Create a customized watering schedule by categorizing your plants (e.g. place the plants that use the same amount of water).
Use compost to enhance the quality of the soil of your garden.
Put your plants in big containers and group them with the smaller plants, so that they can give some shadow to the small ones.

Do not use a salt based, or ion exchange, water softener. These consume excessive amounts of water, and leave brine backwash to pollute the local watershed. Instead, use an electronic de-scaler to prevent limescale buildup and other hard water related problems. Two such options are Scalewatcher or Small Wonder.
Wash clothes using a full washing machine.
Check Repair a Leaking Irrigation System and pipes. For more information contact your local water company for information on how to perform the checks.
Use nontoxic, biodegradable household cleaning products.
Check with your local water officials on ways to protect your watershed. Some jurisdictions have programs in order, such as a hotline you can call to report water waste (e.g. a leaky sprinkler).
Wash your car at car washes, as opposed to doing it with a Choose an Environmentally Friendly Garden Hose.
Never dump anything into a storm sewer! These end up at local rivers, lakes, and streams!