Water Usage Tips

The Water Cycle

The water cycle is the term used to describe the naturally occurring processes of rainfall, evaporation, absorption, storage and use of water in the environment.

The cycle starts with cloud formation and when rain falls, it is collected on the ground and runs into existing bodies of water such as streams,lakes and rivers.Some of this water finds its way back into the environment through evaporation back into the atmosphere and some finds its way into the soil through percolation for use by plants and trees.

The system is dynamic and constantly changing. Weather conditions such as humidity and temperature affect the amount of water drawn back into the air by evaporation or transpiration.The amount of rainfall (or lack of it) affects percolation of water into the soil in the proceeding days and months.

Human use of water affects the water cycle in a variety of ways.Specifically water is drawn from its normal course of function within the water cycle and applied to domestic,agricultural and industrial uses.This diverted water, once used, must be returned to the water cycle somewhere further down stream.

The quality of water within a catchment has a significant impact on environmental and public health.

Water Usage Information


How much water do we use?

During the 2000-2001 financial year, 93 of the largest water utilities across Australia (which between them service 83% of the population) produced on average, 460 litres of drinking water per person per day. They supplied 259 litres of water per person per day to households. Of this only 2 litres per person were actually drunk. The other 201 litres per person were used by industry, in commercial premises, for institutional uses, or were unaccounted for (i.e.stolen or leaked).

Domestic Use

Domestic water consumption varies widely ranging from 350 litres per person per day to1,500 litres per person per day. The average is about 635 litres which is enough to fill about 70 buckets. (A standard bucket will hold 9 litres – about 2 gallons).

General Tank Information

Water is a valuable commodity in Australia. Rainwater collection tanks are an efficient means of reducing the use of expensive potable mains water as well as controlling and using rainwater normally lost as stormwater run-off. Rainwater can provide a renewable supply of natural, soft, clear and odourless water that can be used for a range of purposes including drinking, washing, bathing, laundry and gardening.

Rainwater collected in tanks generally contains few chemicals. However, there may be increased pollution by airborne contaminants in major urban centres and industrial areas. The microbiological quality of rainwater collected in domestic tanks may be lower than that of many mains water supplies. However, providing systems are well maintained the risk of harmful organisms being present is low.

Generally, yes. Providing the rainwater is clear, has little taste or smell and is from a well maintained system, it is probably and unlikely to cause any illness for most users. For those who are immunocompromised such as the very young or very old, cancer patients, people with diabetes, organ transplants, or those who are HIV positive, disinfecting the water before consumption should be considered. This can be achieved by heating and holding at a rolling boil for 1 minute or more.

The provision of good quality water depends on correct design and installation followed by sensible maintenance of the rainwater tank and catchment area. The collection of rainwater involves “LOW maintenance NOT NO maintenance”.

Tanks are available in a wide range of materials including galvanised, AquaplateTM, or zincalume steel, concrete, fibreglass or plastic. All of these materials can be suitable providing the tanks have been manufactured specifically for the collection of rainwater. Some PVC pipes may contain lead so if the water is for drinking purposes, only high quality (“food grade”) plastic pipe and fittings should be used. There have been some reports that water collected from metal roofs can react with steel tanks to cause corrosion. Some types of tanks should be washed or flushed before use. The manufacturer should be able to provide advice on whether this may be necessary. When installed, the tank should be covered and every access point except the inlet and overflow should be sealed unless in use. The inlet should incorporate a mesh cover and a strainer to keep out materials such as leaves and to prevent the access of mosquitoes and other insects. The overflow should also be covered with an insect-proof screen.

In general, house and shed roofs are used as catchment areas. Rainwater can be collected from most types of roof, including asbestos roofs, providing they have not been painted with lead-based paints or coated with bitumen-based materials. Some types of new tiles and freshly applied acrylic paints may affect the colour or taste of rainwater and the first few run-offs may need to be discarded. As a precaution the use of pesticide-treated timbers and lead flashing should be avoided in roof catchments. Also, if possible, rainwater should not be collected from parts of roofs incorporating flues from wood burners.
Overflows or discharge pipes from roof mounted appliances such as evaporative air conditioners or hot water systems
should not be permitted to discharge onto the roof catclunent area.

First flush devices prevent the first portion of roof run-off from being collected and will reduce the amounts of dust, bird droppings and leaves etc. that can accumulate on roofs from being washed into tanks. The provision and use of these devices is mandatory for all rainwater tanks.

Roof catchments should be kept clean and clear of leaves and debris. Gutters should be regularly inspected and cleaned if necessary. The use of screen/guards should be considered. All screens should be cleaned regularly. Tanks should not be allowed to become breeding sites for mosquitoes. If mosquitoes are detected in a tank, the entry point should be located and closed. For most types of tanks mosquito breeding can be stopped by adding a teaspoon of domestic kerosene. Tanks should be examined for accumulation of sludge at least every 2-3 years. If sludge covering the bottom of the tank is evident it should be removed by siphon or by complete emptying of the tank. Professional tank cleaners are also available.

Regular disinfection should not be necessary. If it is suspected that water in the tank is contaminated rainwater can be chlorinated using 40mL of liquid sodium hypochlorite or 7 grams of granular calcium hypochlorite per 1000 litres of water (approx. 5mg/L chlorine).

Rainwater tanks of at least 5,000 litres (10,000 is recommended) are required for new dwelling houses in urban and rural areas. The tank must have sufficient capacity and be connected so as to supplement water for toilet flushing, garden irrigation, laundry, external washing etc. Such tanks will have to be plumbed into main water to top them up during times of low rainfall. Supplemental inflow should not be undertaken until the tank is at least 80% empty. This allows for the tank to buffer stormwater flows to local drainage.

Your local Public Health Unit can provide information on water quality and health (under ‘H’ in Telstra White Pages or at http://www.health.nsw.gov.au/public/phus/phus.html). If you have specific health concerns you should discuss these with your family doctor. More detail about managing and using rainwater tanks can be found in the book `Guidance on the Use of Rainwater Tanks’, published by the National Environmental Health Forum in 1998 (ISBN 0642320160). This is available from Auslnfo Bookshops (0292428500) and copies can be printed from the NSW Health Website: http://www.health.nsw.gov.au/public-health/ehb/water/rainwater.html. Many analytical laboratories can advise on chemical, microbiological and algal testing of water. If you wish to have some water tested your local Public Health Unit can help you find an accredited laboratory or search in the Yellow Pages under “Analysts”.

Where the construction of a new residential dwelling is proposed, details of the proposed rainwater tank are required to be submitted to Council at the time of lodgement of the development application. Where rainwater tanks are proposed to be installed as an ancilliary feature to an existing residential dwelling, tanks up to 5000 litres in size are deemed as exempt development and as such an application is not required to be submitted to Council for determination. Any tanks of a larger size will be subject to lodgement of a development application to be determined by Council prior to installation.

Submersible pumps are recommended as the water within the tank(s) provides insulation to mask pump noise. Any pump external to the tank is to be enclosed in a noise attenuating enclosure and not create a noise problem. the pump must not be audible at the nearest residential property boundary between the hours of 8.00pm and 7.00am Monday to Saturday and 8.00pm to 8.00am on Sundays.

Quick Tips

•A tap left running can waste up to 17 litres of water per minute.
•A leaking toilet can waste up to 16,000 litres of water a year.
•Water efficient taps with an aerator or flow restrictor use 50% less water than standard taps.
•The bathroom uses around 49% of all water used inside the home.
•A dripping tap can waste up to 2,000 litres a month. That’s 24,000 litres a year – that’s more than an average household uses in a month
•An eight minute shower using a regular shower head uses around 120 litres of water. A water efficient shower head uses less than 72 litres.

Every day,there are many simple little things we can do around the house to save water money and help the environment
•Checking for leaks in taps,pipes and dishwasher hoses is an easy way to reduce on water wastage. Remember, one leaking tap can waste up to 2,000 litres of water a month.
•Put the plug in the sink when washing your hands instead of holding them under running water.
•Thaw frozen foods before you need them or use the microwave instead of placing them under running water.
•Prevent taps from leaking by turning them off lightly and replace washers as soon as they begin to leak
•Washing fruit and vegies in a half-filed sink instead of under running water is a great way to cut back on water wastage.
•Rinsing your dished in a plugged sink rather than under a running tap saves water and is just as easy and effective.
•Installing one of the latest AAA Rated Shower heads can give you a great shower and save you around 10 litres of water a minute.They also save you energy costs as you’ll use less hot water.
•To rinse your razor,run a little hot water into a plugged sink. Rinsing your razor under a running tap wastes lots of water.
•There’s no need to leave the tap running while you brush your teeth. Simply wet your toothbrush before you begin and use a glass of water to rinse your mouth.