Understanding Why Water Is a Precious Commodity.
Have you ever woken up and gone to the bathroom, turned on the tap, and discovered that nothing comes out? In your initial panic, you probably wondered how you were going to get through the next few hours — you can’t take a shower, make breakfast or clean your teeth.
Your no-water crisis may have been caused by something like a broken pipe, which can be quickly fixed. Yet over one billion people in the world today have no guarantee of water from one day to the next. And if current trends continue, in less than 20 years, two-thirds of the world’s population is going to suffer regular water shortages. Even the industrialised world is running out of water.
The bare facts are that simply not enough water is available to supply increasing demands. Since 1900, the world’s population has grown two-fold, but global water use has increased six-fold. Reduced rainfall caused by climate change is now exacerbating the problem.
In this chapter, I explain how water supplies work and why the way water is delivered is going to change radically over the next ten years. I show you how these changes may affect you, and what you can do to make sure you’re not left high and dry.
Some facts about water can help you appreciate how dramatic the shortage situation is.
Up to 41 per cent of the world’s population lives in regions that are under water stress — in these areas, water supply is much less than the global average. These parts of the world include northern and central Africa and the Middle East. By comparison, in urban areas of Australia, the United States and Europe, water supply is much higher than the global average. Despite this, the developed world also faces water shortages.
Where your water comes from
Ordinarily, water is delivered to homes and businesses in large urban areas as follows:
1. Water from rivers and streams is collected in strategically placed dams and reservoirs, or drawn from natural underground sources.
Most big cities rely on many dams. Places such as Perth and Alice Springs get their water from underground sources.
2. The water is delivered to filtration plants.
At the filtration plant, much of the sediment and minerals is removed, chlorine is added to kill any living things and fluoride is added to prevent tooth decay.
3. The water is delivered to homes and businesses via a network of pumping stations and pipes.
These networks are extensive. For example, Sydney’s network of underground water pipes is approximately 21,000 kilometres long — the same distance as flying from Sydney to New York via London.
For agricultural and farming purposes, the method is more direct: Irrigation water is pumped straight from a nearby watercourse or groundwater supply. Also, many rural towns pump their water supply straight from natural waterways and channels, and rely on residential rainwater tanks for back-up (for more details about rainwater tanks, see the section ‘Tanking it’ later in this chapter).
Many of the methods used to deliver water are unsustainable. Here’s why:
Damming natural waterways and concreting streams and rivers interferes with and, in some cases, destroys the natural ecosystem.
Drawing too much water from rivers and streams reduces water flow; the removal of vegetation near rivers and streams intensifies sunlight; and agricultural run-off and sewage foul waterways with the wrong kind of nutrients. Algae blooms, which kill aquatic life, flourish under these conditions.
Water drawn from rivers and underground water supplies for irrigation contains mineral salts. When this water evaporates, the salts are left in the top layers of the soil. This process increases salinity, which makes the soil useless for farming.
Unless it rains, dams simply dry up. This drying up is accelerated by evaporation and by rates of rising consumption.
Ageing pipes and infrastructures used to deliver water in urban areas are susceptible to leakages and contamination.
Where your wastewater goes
Getting water to your home, your business or your farm is one thing. But getting rid of the wastewater after you use it is all together another issue.
The term wastewater is used to describe all the water that has been used and then poured down the drain. Here are some of the more common components of wastewater:
Water that runs down the kitchen sink
Water that gets flushed down the toilet
Water from showers and baths
Water from washing machines
Water used in industrial processes
Stormwater is the water that runs off roofs, streets and roads. Stormwater is managed separately to wastewater and usually runs straight into watercourses, along with the debris collected along the way, separated by grates and litter traps. The oil, grease and chemicals in stormwater cause up to half of the pollution in watercourses.
All this water can be recycled. Here’s how:
Greywater: You can safely reuse the wastewater from your washing machines, sinks and showers in your garden. This greywater contains relatively small amounts of pollutants and bacteria. (For information about reusing your greywater, see the section ‘How grey is your water?’ later in this chapter.)
Sewage: Advances in sewage treatment systems allow the water separated at the sewage treatment plant to be put straight back into waterways or used in industry. (For more information about sewage recycling, see the section ‘Recycling urban wastewater’ later in this chapter.)
Stormwater run-off: Although most stormwater currently runs straight into waterways or the sea, this source of water can potentially be stored and reused, with the gunk collected along the way separated from the water. At home, you can capture some of your own stormwater run-off from your roof by installing a rainwater tank. (For more details, see the section ‘Tanking it’ later in this chapter.)
Adopting a Drier Lifestyle
Governments around the world face dwindling water supplies and growing populations demanding more water. To resolve this issue, they’re acting on two fronts:
Technological innovations: Governments apply new technology to better manage the water supply. These developments enable water to be either recycled or drawn from new sources.
Behavioural measures: Education and financial incentives encourage people to use water more conservatively to take the pressure off the water supply. In urban areas, 70 per cent of water consumption occurs in and around homes, so any changes in domestic consumption can have a significant impact.
Government actions aimed at changing your behaviour involve a combination of the ‘carrot and the stick’. The carrot approach uses mainly financial incentives, designed to encourage you to conserve water. These include rebates for purchasing water-efficient washing machines and rainwater tanks. The stick approach forces you to do something, usually by introducing regulations that carry the threat of a fine. For example, water restrictions limit your use of water when supply levels get seriously low, and carry severe penalties. Watering gardens and washing cars are usually the first targets — these restrictions are permanent in some cities and towns. Another approach is raising the cost of water to discourage those who guzzle more than their fair share.
So how do you reduce your water consumption when temperatures rise? Actions you can take include the following:
Don’t waste a drop: Yes, and this resolve is all about being frugal with water. See the following section for more details.
Collect your rainwater: Check out the section ‘Tanking it’ later in this chapter.
Recycle your own greywater: For more details, see the section ‘How grey is your water?’ later in this chapter.
Eliminating wastage
Consuming less water isn’t so difficult. By using water more efficiently, you can significantly cut your water consumption — and coincidentally your water bill
Place aerators on the faucets of all the taps in your home. This device can reduce water flow by up to 50 per cent without reducing water pressure. You can purchase a new water-saving tap aerator at most hardware stores. Just unscrew and remove your existing non-water-saving tap aerator and screw on your new one.
Bathroom: You know the drill — install water-efficient devices and turn off those taps! For extra tips about how to be wise with water in the bathroom, refer to Chapter 2.
Kitchen: Focus on how you use water in the kitchen.
• At the sink, you can waste up to 7 litres of water a minute by rinsing things under the tap. Put the plug in the sink before washing fruit and vegies and rinsing dishes.
• Turn the dishwasher on only when full. Better still; reduce your use of the dishwasher by washing up some of the smaller plates, knives and forks in the sink.
• Use the dishwasher’s economy cycle whenever possible.
Laundry: A front-loading washing machine uses 60 per cent less water than a top-loading washing machine. You can also conserve water by washing full loads less often, rather than washing smaller loads more often. For more information about saving water in the laundry, check out Chapter 2.
Garden: Put away your hose. Watering your lawn, hosing your pathways and raising exotic flowers consume lots of water. In arid climates like Australia, grass lawns are water hogs. Historically, lawns have accounted for up to 90 per cent of water used in Australian gardens, according to Sydney Water Corporation. For more information about maintaining your garden, refer to Chapter 3.
If you have a swimming pool in your backyard, you can reduce water evaporation and avoid constant topping up by covering the pool when it’s not in use — hey, this is more practical than banning the kids from doing water bombs in the pool or splashing water over the sides, don’t you think? Many companies supply custom-made pool covers, but more popular are solar pool covers, or blankets, that can raise the temperature of the water in the pool by 8 degrees Celsius so that you can swim in it more often.
Tanking it
Almost as effective as curbing how much water you use is collecting your own water for free, from the sky. A rainwater tank, which you hook up to your guttering to collect water run-off from the roof, can pay for itself within a few years (if it rains). Most state governments in Australia offer rebates on rainwater tank purchase and installation. In fact, with a rebate, a small tank can effectively cost you next to nothing to set up.
Today’s rainwater tanks are more sophisticated than the round corrugated icon tanks of yesteryear. These days, water tank systems include a range of options, such as first-flush filters to wash away leaves and debris that would otherwise enter the tank; and valves that enable you to switch between using either mains water and tank water to supply the toilet or to supply the hot-water system. Rainwater tanks come in a range of shapes and sizes, which means you can almost certainly find a shape and size that meets your particular requirements for installation. For example, they can be
Integrated into the walls of the house.
Stashed away under the floor (which also helps to cool and heat your home).
Installed in the garden, as shown in Figure 1-1.
In rural areas, tank water is the preferred source of drinking water — an extra tap is fitted in the kitchen. The water pumped from rivers and dams and supplied as tap water is often too muddy and loaded with nutrients and other contaminants to be safe for drinking (although you’re usually safe enough using it for washing dishes, and in the bathroom and laundry).
If you intend to use a rainwater tank for drinking water only, you need a tank with a capacity of somewhere between 400 and 1,000 litres (depending on the size of your family), which range in cost from $500 to $800. Double the size if you want to use the tank to also supply water for your garden. You also need to install a filter to make sure you’re drinking clean water.
How grey is your water?
Why not reuse and recycle water that would otherwise be washed down the drain to water your garden? Governments do it and, thanks to improvements in technology and regulations, you can do it too, at home.
Water agencies define greywater as the wastewater from showers, baths, sinks, laundry tubs, washing machines, dishwashers and kitchen sinks (but not toilets — this water is called black water). The average 3.5-person Sydney household produces approximately 400 litres of greywater each day, which you can decide to save by easily diverting it to the garden. This approach saves you from drawing on water stored in a rainwater tank, or turning on a tap and using fresh drinking water from the mains water supply.
To capture the greywater, you can install either a greywater diversion system or a greywater treatment system. Some of the more sophisticated systems treat the water so well that you can reuse the water again in your toilet or even the washing machine.
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