How to Save Water at Home – Step-by-Step Guide

Water Saving Information - How Local Saving Habits Can Help Save the World

Let’s start with the basics on how to save water at home, and on why saving water on a global level is ever more important.

Any effort at conservation has to start with understanding and measuring your consumption. If you don’t know how much water you’re using, or what you’re using it for, you won’t know where to focus your efforts at saving water.

What motivates you to save water at home might be the cost of municipally supplied water, a limited availability of water from your own well or other local source, watering bans or restrictions for lawn and garden watering, or more global issues relating to water scarcity and water equity.

In this section we’ll cover many of the above issues. But back to water saving basics: you have to start with measurement.

Measure, then Save

You need to measure and understand your water consumption before you can save. Unfortunately, the techniques for measuring water use are more primitive and time-consuming than, for example, electricity monitoring, because of a lack of suitable home water measurement tools.

There are plenty of electricity usage monitors to help you measure the electricity usage of individual appliances, and of course you have the electrical utility meter for your whole home. (In places with Smart Meters, you can even view your household electricity usage hour-by-hour on the Internet!) For many appliances, lights, and other electrical devices, you can read the wattage of the device, multiply that by the amount of time you typically use it in a day, and come up with an estimate of electricity use.

But measuring water usage is quite a bit trickier, because you typically only have access to your whole house water meter; the water meter is often hidden away in a nook or cranny of your basement, making it hard to read on a regular basis; and you’ll find it challenging to measure, or sometimes even estimate, the water consumption of various activities in your home.

Getting Started

To start your measurement campaign, do an inventory of item or activity in your household that uses water. Common items are:

  • Showers and baths
  • Toilets
  • Bathroom sinks
  • Kitchen sinks
  • Dishwashers
  • Washing machines
  • Water and ice dispensers and built-in water filters
  • Outdoor faucets and garden irrigation systems
  • Furnace humidifiers
  • Evaporative cooling air conditioners
  • Outdoor water misters
  • Swimming pools and garden ponds

For each of the items or activities in your inventory, you can do an estimate of the amount of water consumed for a particular use. Here are suggestions for how to estimate some of the more common items in this list:

Shower: hold a large bowl up to the showerhead and turn the shower on for ten seconds. Use a measuring cup to measure the amount of water in the bowl. (For metric users, this is easy. For US gallon users, remember: four cups in a quart, four quarts in a gallon!) Multiply the amount of water by six to get gallons per minute; multiply that by the typical number of minutes you (or your teenage daughter) takes a shower, and multiply that by the number of showers you and other household members take in a month, and you’ll know how much of your household water budget is going towards showers.

Note that a typical showerhead uses 2 to 2.5 gallons per minute at full flow (the US government mandates that no new showerhead over 2.5 GPM flow can be sold) but there are “rain shower” showerheads out there that have flow rates up to 5-6 gallons per minute, while the best low-flow showerheads optimize the water flow to give you a comfortable shower at only 1 to 1.25 GPM.

Toilet: A newer toilet will typically state its flush capacity on the top enamel surface of the bowl, between the seat and the tank, or perhaps inside the tank. My basement toilet, a low-flush toilet made by Kohler says “1.6 gallons / 6 liters per flush”. If the toilet is older you can measure its consumption per flush as follows: (1) with a pencil, mark the porcelain at the water line (or, if your tank is lined with a polystyrene insulator, use a felt pen to mark just above the waterline); (2) turn off the water intake to the toilet (below the tank, typically on the left); (3) flush the toilet the way you usually would; (4) fill a measuring cup or one-quart/one-liter jug with water from another water source, such as your bathroom sink, and count the number of cups or jugs it takes to fill the tank back up to the level you marked. (And don’t forget to turn the toilet water supply back on!)

Very old toilets often have huge toilet tanks with a 5 to 7 US gallon capacity. (A 7 gallon toilet would probably date to before 1950!) The mandated maximum was lowered to 3.5 gallons in the 80’s, and then down to 1.6 gallons in 1992. And you can get dual flush toilets, or a dual flush converter for an existing toilet, that lower the flush rate down to less than a gallon for liquid wastes, and the required 1.6 gallons for solids.

You can estimate toilet water consumption just by taking the gallons per flush rate and estimating the number of times per day the toilet is flushed, then multiply by 30 to get gallons per month. Don’t forget to check for (and fix!) toilet leaks, for example by using toilet leak detecting tablets, since even a toilet that leaks at the rate of 2 drops a second can add 70 gallons, or 260 liters, of water waste a month.

Bathroom sinks are probably not enough of a water user to warrant measuring, but if you see a family member turn the water on to wet their toothbrush, then proceed to brush their teeth for a minute or two, then rinse, all with the water still running, you might want to measure the tap’s flow per minute to let them know how many gallons of water they waste each time they brush their teeth!

Kitchen sinks: Measure the horizontal dimensions (left to right or LR, and front to back or FB) and and estimate the typical depth to which you fill the sink, then multiply as follows:

  • Inches to gallons: LR X FB X Depth / 231
  • CM to liters: LR X FB X Depth / 1000

then multiply that by the typical number of sinkloads you use in a day.

Dishwashers: The EPA/DOE requirements for dishwashers stipulate that a regular dishwasher must use no more than 6.6 gallons per standard cycle, while an ENERGY STAR model must use no more than 5.8 gallons per standard cycle, and their yearly usage estimate is based on 215 cycles per year (3 loads per week). You can do an unscientific estimate water usage of your dishwasher per load as follows:

  • If the dishwasher is from before 2010, assume 7 gallons per cycle
  • If the dishwasher is from 2010/early 2011, assume 6.6 gallons per cycle
  • If the dishwasher is from late 2011 or after, assume 5.5 gallons per cycle
  • If the dishwasher carries an ENERGY STAR label, reduce the appropriate assumption above by 10%
  • If you use the Smart Wash feature, decrease your estimate by 10%
  • If you use the Pot Scrubber or other features that add an extra drain and reload to the cycle, increase your estimate by 20%.

Then multiply your estimate by loads per week, and multiply that by 4.3 to get loads per month.

Washing machines: A conventional top loading washing machine uses about 40 gallons per load, while a front-loading model uses at least 35% less, and as little as 12-14 gallons per load. Extra cycles at the start, and extra rinses, add to this. And a typical American household does one or more loads per day on average!

Garden watering: You can buy an outdoor hose water meter to measure the amount of water you use when watering your garden or lawn, filling a pond or kiddie pool, washing your driveway and so on. Or, if you’re handy at math, place a straight-edged plastic container on the lawn before the sprinklers go off, measure how full the container gets, compute the surface area of the lawn, and calculate gallons or liters from there. For example, here’s a US measurement approach:

  • A straight-edge container gets 1.5 inches of water
  • The lawn is 16 x 20 feet or 320 square feet
  • 1.5 inches x 320 square feet / 12 inches per foot = 40 cubic feet
  • 40 cubic feet x 7.48 US gallons per cuft = 300 gallons

And here’s a metric approach:

  • A straight-edge container gets 5 cm of water
  • The lawn is 4 x 6 meters or 24 m2
  • 5 cm (.05 m) x 24m2 = 1.2 m3
  • 1.2 m3 * 1,000 = 1,200 liters

For other household appliances or typical water use patterns, use a combination of the above techniques and just sensible guess-timating to figure out how much water you’re using per month.

Cut Twice...

Once you have measured your household water use, outlet by outlet, appliance by appliance, and water use pattern by water use pattern, you can look for the biggest water uses and try cutting those back. Remember that activities that consume a little water but are performed frequently (or are running continuously) can use a lot more water than activities that use a lot of water but aren’t done often. For example, suppose you wash your car twice a summer, with the garden hose running an average of 15 minutes each time, at 8 gallons per minute. That uses 120 gallons per wash, or 240 gallons total. Meanwhile, a faucet dripping at the rate of one drop per second uses only 1.14 gallons per day – but 417 gallons per year!

It’s not just a question of being more efficient with each of your activities – consider cutting some activities out or doing them less frequently. In our household one of our big water savers is forcing our kids to do all the sorting, folding, and putting away of the household laundry. How does thissave water? Because the kids quickly realize that their bad habit of throwing once-worn clothes into the laundry even when they’re still pretty clean is rewarded with extra work. Sure, we want them to throw socks and undies into the wash after one wear. But the jeans or t-shirt they wore today might still be clean enough to wear again. Kids tend to choose the path of least resistance: throwing clothes into the hamper is easier than folding them neatly and putting them back in a drawer or closet. But it isn’t easier than doing all that laundry sorting!

How YOUR Actions Can Help Save the World

Your local actions in conserving water can have global consequences. For starters, do you know what greenhouse gas contributes the most to the greenhouse effect? Most people will answer carbon dioxide or CO2. But while CO2 is more potent in its greenhouse effect per volume of the gas, water vapor plays a much bigger role in the greenhouse effect simply because there’s so much more of it:

  • Water vapor (H20) is responsible for 36-72% of the greenhouse effect
  • Carbon dioxide (CO2) is responsible for 9-26%.

When dry areas such as the US Southwest are irrigated for agriculture or gardens and lawns, large quantities of water that might otherwise have stayed in the water table, or flowed out to the ocean in a river, are spread on the ground and are evaporated into the troposphere by plants. Not only does this reduce the amount of available water for future generations (when the water table is tapped) or those downstream (the Colorado river doesn’t even make it to the Pacific any more!), but it increases atmospheric water vapor concentrations which exacerbates climate change.

It takes energy to treat and pump water as well. While the energy required to deliver a glass of water from the water treatment plant to your kitchen sink is inconsequential, it can take a lot of energy required to purify, filter, and pump thousands of gallons of potable water to your garden hose so you can water the lawn every other day.

Climate change – brought on by our excessive love of greenery, but more importantly our excessive use of fossil fuel energy – has not only made the world hotter, but affected the water cycle in many places, with increased drought in much of Africa, and increased flooding during the rainy season in many tropical areas. And while you might think irrigation is a good thing, and putting more land into production will help feed the world’s hungry, in many ways the practice of adding marginal crop lands to our global food production capacity has been bad both for the planet and for the future of human kind. That’s because:

  • Much of our food production depends on fossil fuels to produce fertilizer, which exacerbates climate change
  • Much of what makes land marginal is lack of rainfall to keep crops growing. Farmers have addressed this in many dry areas by using irrigation sourced from groundwater or rivers
  • The more land in marginal areas is converted to irrigated farmland, the more water is diverted from rivers and the more water is pumped out of water tables.

Effects on the water table can be slow but steady (a 4 cm drop per year in average water table height in India) or sudden and severe. The deep water table under Heibei Province in the heart of the North China Plain, for example, dropped by an average of 3 meters or 10 feet just in the year 2000!

These are just a few of the major global water issues we are faced with in the early 21st century. What you do to save water at home will certainly not stop desertification or aquifer depletion worldwide, but with 8,2 billion humans projected to be living by 2025 – and with over 700 million of us big water users in developed countries like the USA, Canada, the UK, Australia, and major countries in western Europe – it’s important that every one of us do what we can to improve our home water savings!

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