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Don't know where to start? Read about all the issues of water use here. Links to actions which relate to each issue can be found in orange.


"In answer to the climate crisis, the economy will need to move away from fossil fuels toward solar, wind and other non-carbon energy sources. But there is no transitioning away from water. Water has no substitutes. And unlike oil and coal, water is much more than a commodity: It is the basis of life." -Yes! Magazine, Will There be Enough?

Although the focus of resource overuse and depletion is most often on fossil fuels, there is a strong argument that water quality and overuse is possibly an even more pressing issue. A typical household of four in Minnesota uses 260 gallons of water per day (Arrowhead Water Quality Team of MN). Much of this water is used in the bathroom. Toilets use 40% of the total, showers/baths and faucets use 35%. By contrast, 15% is used in the kitchen, and 10% for washing clothes. This is not including irrigation and pool water use which can bump total water use per household closer to 400 gallons per day. While this is difficult to comprehend at first, after breaking down the uses of water throughout the day it isn't hard to believe. For example, a household in Phoenix with a backyard pool loses 50 gallons per day to evaporation alone, if the pool is left uncovered as most are (City of Phoenix). A single load of laundry uses 40 gallons, and each family member's shower uses at least 20 gallons each morning.

The graphic below illustrates the places water is used both system-wide as well as in residences (public supply) in Minnesota.

As you can see in the graphic above, residential water consumption referred to as 'public supply' is only one slice of the pie of water consumption. Minnesota uses 1,404 billion gallons of water each year. Of this only 15% (217 billion gallons) is domestic water use. The biggest user is power generation, contributing to 60% of water use.

A lot of water is required for the production of electricity, both in steam generation and for use in cooling machinery to prevent overheating. "About 90 percent of US electricity comes from thermoelectric power: turning water into steam by burning coal, natural gas, or oil, or using the heat from nuclear reactions" (MN DNR).

Not only is water needed to produce electricity, energy is also needed to transport the water from place to place. According to a study in Southern California, 1.6 kWh is needed to transport one cubic meter of water from the Colorado River to Southern California (Postel). That equals six watts per gallon. "The energy required to provide drinking water to a typical southern California home can rank third behind that required to run the air conditioner and refrigerator" (Postel).

An even more energy intensive method of obtaining potable water is desalination. Converting salt water to drinkable water takes 2 kWh per cubic meter (an amount of energy equivalent to running a hairdryer for 40 hours) or 7.6 Wh per gallon. While this might not seem like much, at a rate of 400 gallons used per day per family, at 6 Wh per gallon that is a total of 2,400 Wh (2.4 kWh) per day just for water desalination.

Even more shocking are the statistics outlined in Hoakstra and Champagin's article "Water footprints of nations."

"One cup of coffee requires for instance 1401 gallons of water in average, one hamburger 24,001 and one cotton T-shirt 20,001".

The 400 gallons of water used in an average household each day could be saved by skipping out on one quarter-pound hamburger for a less water-consuming food.

The following table shows a global average amount of water used for some every day products. (in gallons).

Gallons
1 glass of beer (250 ml)75
1 glass of milk (200 ml)200
1 cup of coffee (125 ml)140
1 cup of tea (250 ml)35
1 slice of bread (30 g)40
1 potato (100 g)25
1 apple (100 g)70
1 cotton t-shirt (250 g)2000
1 sheet of A4 paper (80g/m2)10
1 glass of wine (125 ml)120
1 glass of apple juice (200 ml)190
1 glass of orange juice (200 ml)170
1 egg (40 g)135
1 hamburger (150 g)2400
1 tomato (70 g)13
1 orange (100 g)50
1 pair of shoes (bovine leather)8000

The 1992 Federal Energy Policy Act required all toilets, sink faucets and showerheads manufactured in the United States after January 1, 1994 be low-volume fixtures. Toilets must use no more than 1.6 gallons per flush (gpf); sink faucets no more than 2.5 gallons per minute (gpm); and showerheads no more than 2.5 gpm. Fixtures installed before 1994 were not required to be retrofitted; therefore, 5 to 7 gpf toilets and 3 to 4 gpm sink faucets and showerheads are still in extensive use throughout the United States.

While our total personal 'water footprint' is much larger than just the water we use when turning on the tap at home, the household is also the context where we have the most power as individuals to change overall water consumption. Residential water use can be broken down into these four categories: toilets, shower/bath/faucets, kitchen and washing clothes:


UNDERSTANDING ALL WATER USE

Most people may be surprised to see how water is used in their home.
This action focuses on simply tracking home water use to gain an awareness of where water is used.


TOILETS

Toilets account for almost 40% 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 (Arrowhead Water Quality Team of MN data.). The average person flushes the toilet five times daily. With an average flush using 3.5 gallons this adds up to 17.5 gallons of water used each day to flush human waste. Because we are not drinking water from our toilets, it is not necessary to clean this water to the same degree as water used for other purposes. However, because toilet water is piped into our homes in the same way as all other water uses, it uses a huge and unnecessary amount of energy for this cleaning and transportation.

Replacing an old toilet with a new ultra low-flow model will reduce each flush down to 1.6 gallons per flush, however, this is not a feasible solution for many people in the short term. The following actions are options for reducing toilet flushing water consumption:


SHOWER/BATH

The average 10 minute shower uses anywhere from twenty to forty gallons of water. Showering is the largest daily water use outside of irrigation for lawns. A 'low flow' showerhead has a flow rate of 2 gallons per minute (20 gallons for a 10 minute shower) while the average showerhead is 4 gallons per minute (40 gallons for a 10 minute shower). By using less running water in the shower everyday, you can save up anywhere from 10-20 gallons of water.

There are various ways to reduce your showering water consumption:


WASHING CLOTHES

Washing clothes accounts for 10% of all residential water use, a statistic which is not surprising when we consider that the average washing machine uses 42 gallons per load (EPA).

When washing machines were first designed, water often had to be carried and heated over a fire before being used. Thus, washing machines were designed to be more water efficient than hand-washing water, reusing water over again for progressively more dirty laundry. However, as running water became a modern convenience, the design of washing machines responded by using more and more water as it became more easily available.

Doing laundry today uses as much as 42 gallons per load. Although washing machines are now made to be as low as 10 gallons per load, this is still a large percentage of household water use. Washing laundry by hand (if done water-consciously) can be a good alternative for reducing laundry-associated water consumption:


HOT WATER ENERGY USE

Energy used for water heating accounts for 13% of all home energy use in the United States. To get an idea of how much energy water heating accounts for in your own home you can check your natural gas bill (if gas heated). A typical natural gas bill includes both space heating and water heating. In Minnesota, the heat may be on from November to April. By averaging out the months when the heat is off, you can get a typical value of water heating energy.


KITCHEN

The third largest use of water in households is for kitchen use and accounts for 15% of all residential water use. Almost all of this is from washing dishes (either by hand or in a dish washer). Typical dish washers use 12-15 gallons of water on a regular cycle, while newer washers use 6-9 gallons per load. On the other hand, 16 gallons of water is typically used to wash these dishes by hand if the faucet is kept running. If hand washing is done in a basin of water or habits of running your dishwasher are changed, dish-washing water can be reduced dramatically:


LAWN IRRIGATION

Irrigation of our residential lawns and public spaces accounts for 10% of all water used in Minnesota annually (Minnesota DNR). This is a significant use when compared to the 15% of annual water use that makes up all other residential water consumption (including toilet flushing, showering and all other home use). Luckily, irrigation water consumption has a simple solution: capture rainwater on site and store in rain barrels until needed. In addition to saving water, capturing rainfall to use for irrigation on site has many other pollution and energy reducing affects.

Another tactic for nearly eliminating water needed for lawn irrigation is to re-landscape your yard with native landscape plantings.


THE END GOAL

All of the actions in this section are smaller pieces of a larger end-goal of living within our natural water allocation dependant upon natural rainfall. The way in which water is currently collected, cleaned and distributed is inherently unsustainable.

As can be witnessed watching the Mississippi river rise during any rainfall in Minneapolis, all water which falls on densely paved urban areas is quickly transported into rivers and streams via gutters on city streets and storm sewers. After washing over roads collecting oil and pollutants, this water is then rapidly funneled into nearby rivers and streams. It must then be transported to water management facilities to remove the pollutants making it safe to drink. The city of Minneapolis boasts approximately 1,000 miles of water mains in the city, “enough to stretch from here to Denver” (City of Minneapolis). Lastly, this water is transported back to exactly the locations where the water originally fell as rain.

Even more energy-intensive water management strategies exist in locations such as Orange County, California, an area which has adopted sewage treatment and desalination strategies in order to keep up with a growing demand for water. Sewage treatment required $490 million worth of pipes, filters and tanks for purification (Zimmerman). This process costs $525 per acre-foot (325,851 gallons in an acre-foot), while desalination costs up to $2,000 per acre-foot.

For the sake of comparison, let’s consider the cycle of water which occurs naturally. As water falls as rain and lands on vegetated areas, many of the pollutants it captured while falling through the atmosphere are soaked up into plants. It is further cleaned as it seeps through clay, sand and rock into aquifers into the groundwater basin. It is then transported slowly into rivers and lakes, evaporating into the atmosphere. By the time water falls as rain it is clean enough to drink.

In the end, we have created a system of water distribution and cleaning which requires energy to perform all the duties that nature already provides for us-should we take advantage of them. This is a problem of both design and over-consumption. For example, the city of San Diego imports 90 percent of its water, much of it from the Colorado River. With rainfall averages of 10-15”/year, San Diego could dramatically reduce its water imports by capturing rain water.

Many people may be similarly surprised to see the quantity of water which can be collected from rainwater alone. Minneapolis gets 29.3 inches per year of rainfall which is a mid-range average precipitation when compared to the rest of the country. There are many regions of the country which get much less rain (Arizona, Southern California and Nevada), as well as regions which get more, such as the coast of Washington and Oregon.

Why not take advantage of the ‘free’ distribution processes of nature? Collecting water on the roofs of homes and businesses requires little to no energy or cleaning and decreases the contamination of fresh water through run-off pollutants.


RESOURCES