Plumbing Basics: Water-saving Strategies

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Conserving Water Inside and Out

Did you know that a leaky faucet in your house can waste as much as 24,000 gallons of water every year, or that recent studies show that homeowners watering their lawns consistently apply at least twice as much water as their lawns actually require? In some areas, the need for conserving water is critical. But no matter where you live, wasteful water practices can be both expensive and ecologically unsound.

Using water wisely

The first step in conserving water is to understand how much water you and your family use for various activities. (To determine your water usage, see the chart below.) With that information, you can better plan and manage your use of water.

Inside a house, more water is used for flushing toilets than for any other activity. Next on the list are showers and baths, and then washing machines and dishwashers. Whenever possible, convert your water-wasting fixtures to water-conserving ones.

Remember that your everyday practices are a key aspect of water conservation. Changing how, and for what, you use water can be your most effective water-saving strategy.

Saving water in the house

You can also significantly reduce water consumption in your home by adopting some or all of the following practices.

• Don’t let water run. Turn it off while you’re shaving, brushing your teeth, or doing dishes by hand. Pre-rinse dishes for the dishwasher in a pan, not under running water, or just scrape them with a utensil or wipe them with a napkin.

• Don’t use running water to thaw frozen food.

• Chill drinking water by putting some in a container and storing it in the refrigerator.

• Avoid using your garbage disposer more than necessary; it requires lots of water to work properly. Instead, throw trimmings in the trash, or, better yet, put them in your compost pile.

• Keep a basin in the kitchen sink.

Wash vegetables in it, cleaning them with a brush, or use the basin to catch water in which you’ve rinsed fruits, vegetables, and the like. Reserve cooking water and use it to water outdoor plants or to run the garbage disposer.

• Take shallower baths. Put the stop per in before you start to run the water: that first bit of cold water will quickly mix with warm to give you the desired temperature.

• Take shorter showers. As the shower water warms up, capture it in a bucket and then set the bucket at your feet while you shower. Pour a bucketful of water into the toilet bowl to flush it manually.

• Flush the toilet only when necessary. Never use it as a wastebasket or ashtray.

• Attach a combination stream-spray aerator to the bathroom sink faucet if the spout will accommodate one. Use the steady stream to quickly wet a toothbrush; for hand-washing, use the more efficient spray.

• Run dishwashers and clothes washers fully loaded, even if they have adjustable water levels. Use the shortest cycles possible on both machines. (For more on energy-saving dishwashers, see our articles on the subject elsewhere in this Guide.)

Where does your water go?


Gallons used

  1. Washing machine (standard)
  2. Toilet (standard)
  3. Toilet (ultra-low flush)
  4. Toilet with silent leak
  5. Toilet that “runs”
  6. Dishwasher (standard)
  7. Dishwasher (water-saver)
  8. Sink-washing dishes (tap running)
  9. Sink-washing dishes (filled sink)
  10. Garbage disposal
  11. Faucet (kitchen)
  12. Faucet (bathroom)
  13. Faucet, leaky
  14. Shower head (standard)
  15. Shower head (low-flow)
  16. Bathtub
  1. 35 to 70 per load
  2. 3½ to 7 (or more) per flush
  3. 1.6 (or less) per flush
  4. 40 per day
  5. 5 per minute
  6. 14 to 30 per load
  7. 11 to 27 per load
  8. 5 per minute
  9. 5 to 10 per wash
  10. 3 to 5 per minute
  11. 5 per minute
  12. 5 per minute
  13. 1/3 per hour
  14. 5 to 8 per minute
  15. 1½ to 3 per minute
  16. 25 to 35 per bath


Gallons used

  1. Lawn (20 by 40 feet)
  2. Sprinkler (standard)
  3. Drip-irrigation emitter (one)
  4. Hose (½-inch diameter)
  5. Hose (5/8-inch diameter)
  6. Hose ( diameter)
  7. Faucet with slow drip
  8. Faucet with fast drip
  9. Faucet with fast leak
  10. Washing car (hose running)
  11. Washing car (with hose shutoff)
  12. Uncovered pool (18 by 36 feet)
  13. Covered pool (18 by 36 feet)
  1. 2,000 to 4,200 per month
  2. ½ to 4 per minute
  3. 1/4 to 2 per hour
  4. 300 per hour
  5. 500 per hour
  6. 600 per hour
  7. 350 per month
  8. 600 per month
  9. 2,000 per month
  10. 100 to 200 per 20 minutes
  11. 15 or more per 20 minutes
  12. 900 to 3,000 per month
  13. 90 to 300 per month

Saving water in the garden

One of the best ways to conserve water in your garden is to use drip irrigation for your plants. If you already have a sprinkler system, you can convert some of your heads to drip.

Here are some additional ways to conserve water outside your house.

• Adjust watering schedules. Let the weather be your guide for watering frequency.

• Build watering basins. They direct water right to the roots of shrubs and small trees.

• Control runoff on slopes. Put headers or basins down-slope from plants.

• Irrigate early or late in the day. In the morning and evening, the air is still and evaporation is minimal.

• Maintain drip systems. Periodically check them for clogged or broken tubing or emitters.

• Maintain sprinklers. Inspect your sys tem at least once a month during the watering season. Clean clogged sprinkler heads, replace broken sprinklers or risers, and adjust heads so their spray doesn’t wet any paved areas.

• Mulch plantings. Materials such as ground bark, compost, and leaf mold help to keep the soil cooler, reduce evaporation, and discourage the growth of weeds. Under large trees, let fallen leaves or needles accumulate as natural mulch.

• Pull weeds or mow them. Left to grow, weeds compete with ornamentals for limited water.

• Put up shade-cloth. Protect tender plants, such as young Japanese maples, from hot sun by covering them with shade-cloth.

• Repair leaks. Fix dripping outdoor faucets and bad hose connections as soon as they occur.

• Shade strawberries. Cover strawberries with shadecloth, but be sure to allow good ventilation. After harvest, withhold water from most of the plants; continue watering a few so you can divide and replant in autumn or winter.

• Sweep driveways and paths. Use a broom rather than a hose spray to clean off paving.

• Water cane berries sparingly. After harvest, especially in coastal climates, established blackberry plants can get through summer on no water; raspberry plants will survive on very little.

• Time watering carefully. Use your irrigation system’s automated controller, changing it as necessary for different weather conditions. If your system is manual, set a kitchen timer to remind you when it’s time to turn off the water.

• Use soaker hoses. Though they’re less efficient than drip, soaker hoses are inexpensive and easy to use between rows of vegetables and around big trees.

• Thin deciduous fruit. Thin apples, peaches, and plums to 10 to 12 inches apart. Let the trees go dry after harvest; water only if the leaves begin to wilt.

• Water efficiently when using a hose. Equip the hose with a shutoff valve so you can turn off the water as you move from plant to plant.

• Water roses sparingly. After spring bloom, many established ones, especially old shrub and species types can get by with little water. Don’t deadhead; let hips develop to sup press plant growth.

• Withhold fertilizer. Don’t feed trees or shrubs; fertilizer stimulates new growth, which increases the demand for water.

Detecting a running toilet

A toilet that runs with a steady flow can waste as much as 5 gallons of water a minute, which adds up to 7,200 gallons per day. Of course, you can hear the flow of a toilet that runs this heavily.

Harder to detect is a toilet that leaks slowly. Even an imperceptible toilet leak can waste as much as 40 gallons of water each day.

To check your toilet for a leak, remove the tank lid and add about 12 drops of colored dye to the water inside. (Blue food coloring will work, or ask your water company for dye tablets.) Then wait 5 minutes to see if the dye flows into the bowl. If it does, water is escaping either through the top of the overflow tube or past the tank stopper and valve seat.

A float ball that’s riding too high lets water overfill the tank and spill down the overflow tube into the bowl. When the chain or lift wires between the flush handle and the stopper at the bottom of the tank get kinked or fouled, the stopper is prevented from sealing the valve seat. Or the stop per or valve seat may be worn and closing improperly (this is usually the problem if you can jiggle the handle to stop the leak).

We will soon show you how to make the repairs yourself.

Drawing A. Components of a toilet .

Water-conserving Fixtures

Retrofitting or changing some of the water-using fixtures inside your house to make them more water efficient can result in substantial water savings. Some changes, such as retrofitting toilets and replacing standard shower heads with low-flow heads, require little effort. Replacing a toilet is more complicated but still within the realm of the do-it yourselfer.

Retrofitting and replacing toilets

Because toilets consume more water than any other household appliance or fixture, they’re the best place to begin upgrading for water conservation. If your existing toilets are water wasters—requiring more than about 3½ gallons per flush—you can either retrofit them with devices that cut back water usage or replace them with low- flush models.

All new toilets must meet the American National Standards Institute’s (ANSI) stringent hydraulic performance standards, which cover bowl cleaning, removal of solids, and drain line carry over a distance of 40 feet. On new toilets, look for a stamp or sticker of approval; the number of gallons used per flush should be printed in the tank or on the packaging.

Before installing a new toilet in an older house, check the offset, the distance between the back wall studs and the center of the drain hub (mea sure to the hold-down nuts). New toilets are designed for a 12-inch offset. In older houses, the offset may be greater, pushing the toilet away from the wall.

For instructions on replacing a toilet, click here.

Retrofitting your toilet. Installing any of several water-saving assemblies in your toilets (see Drawing 1) can make them more efficient. Most devices can be installed in just a few minutes; simply follow the manufacturer’s instructions.

One device, an adjustable flush valve, replaces a conventional ball cock and stopper, or flapper. You adjust it to close once flushing is complete and the tank and bowl are filled to a given level. The adjustable valve prevents water from escaping down the flush valve while the tank is refilling. This device will typically save from ¾ to 1½ gallons of water per flush, depending on the adjustment and your toilet.

A related device, the variable buoyancy flapper, rides up and down on the overflow tube and closes the stop per before all of the water rushes from tank to bowl. The water that does rush through still moves with its original full force. When such a device is put into a 5-gallon toilet and adjusted to save 2 gallons, all 5 gallons of water are still moving downward once flushing starts, but the stopper will close while 2 gallons still remain in the tank.

Dual-handle flush mechanisms work in a similar way, but they give you a choice. You can still use the full flush with one handle, but you have a second handle that releases up to 75 percent less water—still enough force to carry away liquid waste.

Water-displacement devices, such as jugs of water and dams, reduce the amount of water that flushes from a toilet’s tank. But because they displace the amount of water in the tank, they also reduce the force of the water rushing into the bowl, the action that makes a typical siphon-wash toilet work properly. The key is to size the displacement device to allow enough water for a proper flush.

Drawing 1. Retrofit toilet devices include an adjustable flush valve, a variable buoyancy flapper, a dual-handle flush mechanism, and a toilet dam. Each reduces the amount of water used for flushing.

A best bet: ULF toilets. A family of four can cut indoor water use by up to 20 percent simply by replacing existing toilets with new ultra-low-flush (ULF) ones. Extremely water efficient, ULF toilets use no more than 1.6 gallons per flush, compared with 5 to 7 gallons or more for older toilets. Some water districts even offer a rebate if you install a ULF toilet.

Most first-generation water-efficient toilets simply reduced the amount of water in each flush cycle without changing much else. Double-flushing and drain clogs were common with these “improved” versions.

The ULFs, however, represent new engineering as well as new design. Steeper bowl sides, shallower traps, smaller siphon outlets, and 5-gallon tanks that only release 1½ gallons of water per flush (but use all 5 gallons of force and pressure) make them per form better than many units that use twice the amount of water.

Other water-saving toilets. Among the other water-efficient toilets you can buy (check local codes first) are a gravity-flush one that uses as little as 3 liters (3.3 quarts) of water, a 1-quart vacuum-assist flush model, and a “foam-flush” toilet that uses only 1 cup of water (a detergent foam generator eliminates friction inside the bowl).

Saving water in the shower

Another way to reduce water consumption significantly is to limit the amount of water that flows through your shower head.

Low-flow shower heads and flow restrictors. Installing a low-flow shower head or flow restrictor (see Drawing 2) is an easy way to cut down water use. Depending on head design and water pressure, such devices can re duce maximum flow to less than 2½ gallons per minute, compared with 5 to 8 gallons per minute put out by standard fixtures. A flow restrictor is simply a washer or insert that you in stall between the inlet pipe and shower head to restrict the amount of water that passes through the shower head.

The cost of low-flow heads and flow restrictors is minimal. But be aware that less expensive models deliver such fine water droplets that they won’t wet your body very quickly—and may even feel a little cool by the time they get down to your knees.

Quality low-flow shower heads are designed to give you a satisfying shower even though they sharply reduce the amount of water required. Inside these heads, water travels through special chambers and orifices that size water droplets, tightly focus the stream, and — with some types—mix air with the water to create a forceful, turbulent spray.

Low-flow heads come in two types: stationary fixtures (typical shower heads) and hand-held models. Hand-held ones are more versatile and use less water than stationary heads because you direct the flow. Most hang on a wall-mounted hook or bar.

Each, model offers different features. Look for adjustable spray set tings and a head with a shutoff that reduces flow to a trickle while you soap up (see below).

To replace a shower head, unscrew the old head by hand or with an adjustable wrench. If necessary, hold the inlet pipe in place with a pair of locking pliers (wrap the jaws with a rag to keep from scratching the finish). Follow the manufacturer’s directions for installation of the new head.

Shower head shutoffs. Also consider a valve near the shower head that lets you shut off the water while you’re soaping up or shampooing (see Drawing 2). These valves, built into many of today’s shower heads, dribble when closed so water in the pipe stays at the selected temperature. Generally, your water will be off for about half your shower time, so water savings will be proportional.

Drawing 2. Flow restrictor, low-flow shower heads, and shower head shutoffs.

Kitchen water savers

Faucet shutoffs are available for kitchen sinks (see Drawing 3). Though it seems easy enough to simply turn off the water as you’re washing vegetables or dishes, an at-the-tap valve makes the task virtually effortless, so you’ll be much more apt to use it. Some are combined with an aerator, which mixes air into water, reducing the amount of water needed by up to 60 percent. Others are threaded so you can reconnect your old aerator.

Drawing 3. Faucet shutoff for a kitchen sink offers convenient and immediate water control.

An instant hot-water device will give you 190° to 200° water on demand. No water is wasted for warm-up.

Underground Leaks

Leaks in the underground pipes bringing water to your house can result in losses that make your water bills read as though you’re squandering water, even when you’re doing your best to con serve. Such leaks can easily go unnoticed when camouflaged by lawn sprinklers, heavy irrigation, or plantings.

Here’s how to find underground leaks outside your house. (Instructions for dealing with leaks in interior pipes is presented here.)

Is there a leak?

It’s simple enough to find out if you’re “consuming” water when you haven’t even turned on a spigot. Go around the house and make sure everything is off: appliances should be through cycling (turn off the icemaker), and faucets should be shut. Then open the cap of your water meter to expose the valve gauge and put a mark on the rim where the dial needle is pointing. (If you have several dials, mark the one indicating 1-cubic-foot increments

Don’t run any water for 30 minutes. Then check the meter. If the indicator has moved from your mark, you have a leak. (The meter may also have a little triangle that spins to show flow; its movement is further evidence of leakage.)

Determining water loss

By keeping track of both the time and the dial’s movement, you can figure the amount of water loss. If you waited 30 minutes between checks, multiply the incremental change by 2 to get an hourly total. The gauge is calibrated in cubic feet; 1 cubic foot is about 7 1/2 gallons. So a 2-cubic-foot change in 30 minutes would be 2 x 2 x 7½: a loss of 30 gallons per hour.

Locating the leak

Walk around the outside of your house, checking where you know pipes run. Look for any wet spots or sinkholes in your lawn; check paving and walls for cracks.

If you have a swimming pool, be aware that its pipes can leak, too. If the water level in your pool drops much more than 1/4 inch per day under normal, calm conditions—or more than ½ inch in a desert climate—you may have a leak (a covered pool should show virtually no loss). Test by putting a piece of tape on the tile at water level; check again in 24 hours.

If you see no evidence of water loss, consider calling in an expert. In the past, the way to find a leak was for a plumber to make an educated guess, followed by trial-and-error digging. Today, electronic leak-detection devices can identify a leak’s location to within a few inches, even through several feet of concrete; they can also determine the depth of the leak. To find a leak-detection service, search online for “Pipe and Leak Locating” in your area.

Most professional leak-detection services will fix a leak if they find one (if you want to do your own repairs, we will cover DIY options in another section). They’ll also test the line to see if there are any additional water losses that were obscured by the main leak. As a bonus, the leak-detection service will allow you to map most of your exterior plumbing lines for future reference.


Basic water-saver: a pool cover

Unless a swimming pool is covered, each summer month hundreds of gal- Ions of water will literally vanish into thin air. Depending on climate and location, an 18 by 36-foot pool can lose from 900 to 3,000 gallons of water per month. Considered another way, an uncovered pool with a 20,000-gallon capacity could lose its total volume of water to evaporation in a typical one-year cycle. For a family of four, that represents 83 days of normal living, figuring 60 gallons of water per person per day. A pool cover can pre vent more than 90 percent of this potential loss.

The two basic styles of cover are those that float on the surface and those that are mounted to the pool’s edge or decking. The floating, or “solar blanket,” styles are the least ex pensive. However, they’re potentially the most dangerous. Because a free- floating cover offers no support, a child or pet could slip under the water and be unable to push the cover away.

The most familiar and least ex pensive floating covers are “bubble pack” covers, made of 12-mil plastic with an ultraviolet-light inhibitor. Another type of floating cover is made of closed-cell foam covered with woven polyvinyl.

Of the mounted covers, the best ones are made of vinyl with a dacron mesh, and contain algicides and ultraviolet-light inhibitors. The safest ones completely cover the pool and will support the weight of several adults.

Some mounted covers are manually operated—you pull them up out of the water or roll them up on rollers mounted at poolside. These covers can be cut to fit irregular shapes.

Automatic pool covers require tracks with built-in pulley systems to guide them into position. Though the tracks can be built unobtrusively into the edge of a pool during construction, for retrofits they usually must be screwed to the decking. Because the covers run in parallel tracks, they can only be rectangular in shape.

Gray Water Systems

Gray water refers to household water recycled from showers, bathtubs, bath room sinks, and washing machines. Gray water collected from all these sources can supplement your garden’s water supply by at least 100 gallons per person per week.

Be aware that not all household water can be reused. For example, much of the water from dishwashers and kitchen sinks (except rinse water) is contaminated with grease and food particles. Toilet waste water, called black water, should never be collected.

Drawing 4. To collect gray water, cut into the vertical drain lines of sinks, showers, and tubs; install Y fittings and ball valves as shown at right. New piping carries washing machine water (see inset) to the storage tank when desired.

Precautions for using gray water

Even the use of “clean” gray water raises safety concerns, the primary one stemming from gray water’s highly variable quality and possible contamination by bacteria, viruses, and para sites. Individuals can be infected by swallowing or inhaling those organisms.

Though health officials have frowned on the use of gray water in the past, decreasing water supplies have caused some communities to al low its use for specific purposes. For the rules about gray water in your area, call your building, health, or water department. Still, be advised: Most building codes prohibit altering household plumbing to collect gray water without a permit.

Minimizing health risks. The health risks from gray water are minimal if you collect and apply it properly. Never collect wash water contaminated by soiled diapers or by people with infectious diseases, or used in poultry or wild game preparation. Also, avoid collecting greasy, soapy water full of suspended solids.

If you collect gray water, don’t wash strong chemicals down the sink. Such chemicals include products for opening clogged drains and products containing boron, chlorine, or sodium. Also, don’t collect water that has run through a water softener. Of the standard laundry soaps, liquid detergents have less sodium than powdered ones, and bio degradable ones are usually the least harmful. Most plants do well on gray water and will not be affected by mild soaps or shampoos.

When using gray water, be sure to follow these basic precautions:

• Always use gray water the same day it’s collected.

• Don’t let it puddle or stand where it won’t be absorbed quickly.

• Don’t spray or sprinkle it.

• Wear rubber gloves whenever you handle gray water or equipment that comes in contact with it.

Where to use gray water in the garden. You can use gray water to irrigate fruit trees, ornamental trees and plants, flowers and ornamental ground covers, and lawns. Do not use gray water to irrigate vegetables or fruits you intend to eat without peeling or cooking. Exceptions are crops such as corn, beans, and tomatoes, where the edible parts are well above the ground. Don’t use it for seedlings, container plants, or acid-loving and salt- sensitive plants.

Collecting gray water

A gray-water system installation usually involves connecting new pipes to the drainpipes of some plumbing fixtures, diverting the gray water through those pipes to a storage tank, where it’s filtered and stored for up to a day, and then distributing the water. If this type of collection is legal in your area, you’ll probably need a permit; washing machine plumbing may be excepted.

Making drain connections. Cut into drainpipes (see Drawing 4) from sinks, bathtubs, showers, and the washing machine. (To collect water from main plumbing lines on showers and many bathtubs, the pipes must be accessible from a crawlspace or basement.) Install Y fittings and ball valves to divert water either to your gray water system or to the standard drain. Use ABS (acrylonitrile-butadiene-styrene) drainpipes to carry the gray water directly to the storage tank.

Always provide for overflow into the sewer line in case the system backs up, and install a check valve between the tank and the sewer line to prevent sewage backup into the tank.

Making a tank. Tanks can be made from metal drums, plastic or fiberglass drums made for food, or 35 to 55- gallon plastic trash cans (see Drawing 5). Ideally, the tank should be located above the landscaping to be watered so water can be distributed by gravity.

To screen out hair and large particles in the gray water, make a shallow basket from 1 hardware cloth and hang it inside the tank just below the rim. Provide handles so you can lift it out frequently for cleaning. Lining the screen with a bit of straw makes it easier to clean.

Near the bottom of the tank, in stall a shutoff valve and a fitting that will accept a ¾-inch garden hose. For a plastic drum, drill a hole and install a tank nipple, a shutoff valve, and then the ¾-inch hose fitting. For a metal drum, have a welding shop install a ¾-inch metal pipe nipple. Add a nipple for overflow piping near the top

If the tank sits below grade or the garden slopes up above the outlet, install a sump pump. Add a check valve between the pump and the irrigation line to prevent backup.

Remember, too, that no matter how well the water is filtered, storage tanks need periodic cleaning. Use a hose to flush the tank; then drain the tank by opening the shutoff valve.

Distributing gray water

Health officials believe that the safest way to apply gray water is below the soil surface or under 4 inches of mulch. Below-surface applications eliminate human contact, and the soil filters out any harmful organisms.

To do this, you bury perforated pipe in a shallow trench filled with gravel. Buy 10-foot lengths of 3 or 4-inch rigid styrene drainpipe, with double rows of holes drilled along the length. Glue a 90° sweep fitting onto each end and add short lengths of pipe that will stick about 6 inches above the ground. Press a cap fitting onto each pipe (don’t glue the fittings).

Shovel a few inches of 1 to 2- inch crushed rock into the trench, set the pipe in place, and level it. With the short pipe lengths pointing upward, bury the pipe beneath a few more inches of gravel; then top with soil.

Put in one of these 10-foot-long systems wherever you intend to de liver gray water. When you’re ready to water, remove one cap, insert the hose that connects to the storage tank, and open the valve or turn on the pump. Simply move the hose from one system to the next to complete watering.

Don’t try to connect a drip irrigation system to gray water distribution. Water for drip irrigation must be screened through fine filters that will clog frequently if gray water is used.

Drawing 5. Collection tank for a gray water system filters the water and stores it for up to a day.

Next: Plumber's Glossary


Main Contents:

  1. Plumbing Question-and-Answer
  2. You’ll Need to Know …
  3. Fix-it Guide
  4. Pipefitting Know-How
  5. Plumbing Improvements
  6. Exterior Plumbing
  7. Water-saving Strategies
  8. Plumber’s Glossary

Feature Articles:

    • How to read your water meter
    • Minimizing overflow damage
    • Turning off the water
    • Preventing clogged drains
    • Face lifts for fixtures
    • Septic tank maintenance
    • Preventive care for garbage disposers
    • Closing down plumbing for the winter
    • Energy conservation tips
    • Caring for new fixtures
    • Adding a second sink
    • Heating water with the sun
    • Which emitters are right for your system?
    • Where does your water go?
    • Detecting a running toilet
    • Basic water-saver: a pool cover

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