harvesting rainwater – a safe, sustainable water source · when planning the installation of a...

Harvesting Rainwater – A Safe, Sustainable Water Source

Harvesting Rainwater – A Safe, Sustainable Water Source....................................................................................... 1 Rainwater Harvesting – the way of the future ........................................................................................................ 2

What is Rainwater Harvesting?.......................................................................................................................... 2 Why We Need to Conserve Water ..................................................................................................................... 2 A scarce resource ............................................................................................................................................ 2 The benefits of Rainwater Harvesting ................................................................................................................ 2

Rainwater Harvesting saves water, money and helps the environment ............................................................. 2 Main household uses of water........................................................................................................................... 3

Systems and products for Rainwater Harvesting ..................................................................................................... 4 10 Steps to Rain Harvesting Sustainable Water................................................................................................... 4 How to Create a Complete Rain Harvesting System............................................................................................. 6

Water Storage and Tank Selection ........................................................................................................................ 7 Choosing the size of your tank .......................................................................................................................... 7 Above or below ground .................................................................................................................................... 7 Polyethylene or Plastic Tanks ............................................................................................................................ 8 Metal tanks ..................................................................................................................................................... 9 Concrete tanks ................................................................................................................................................ 9 Fibreglass tanks............................................................................................................................................. 10 Bladders and other innovative solutions ........................................................................................................... 10

‘Wet’ and ‘Dry’ Systems...................................................................................................................................... 12 ‘Wet’ Systems................................................................................................................................................ 12 ‘Dry’ Systems ................................................................................................................................................ 12 Converting a ‘wet’ system to ‘dry’ .................................................................................................................... 12

Pump Selection.................................................................................................................................................. 14 Distributing water for use around the home ..................................................................................................... 14 Pressure Vessel Pumps................................................................................................................................... 14 Constant Pressure Systems............................................................................................................................. 14

Regulation and Rebates ..................................................................................................................................... 15 Incentives for the community ......................................................................................................................... 15 New standards for Energy and Water Efficiency................................................................................................ 15 Rainwater Tank Installation Guidelines ............................................................................................................ 15 Plumbing Regulations..................................................................................................................................... 15

About Us – Rain Harvesting Pty Ltd ..................................................................................................................... 16 Our vision ..................................................................................................................................................... 16 Development of the product range .................................................................................................................. 16 Contact Us .................................................................................................................................................... 18

Prepared by Rain Harvesting (Oct 06).. For more information, including details of products for collecting good quality rainwater, visit www.rainharvesting.com

Rainwater Harvesting – the way of the future

What is Rainwater Harvesting? Rainwater harvesting (also called roofwater harvesting) involves the collection, storage and distribution of rainwater from the roof, for use inside and outside the home or business.


Why We Need to Conserve Water

A scarce resource Water is a scarce resource that is essential for our existence and our supplies are increasingly coming under pressure. Only 3% of the world’s water is fresh and less than a third of 1% of this is available to humans. Governments are working frantically to develop solutions to these shortages and have introduced sweeping water restrictions which have put the issue of water conservation front of mind for the community. There is an urgent need to take action due to: 1. increasing water usage due to population

growth 2. the effects of climate change (including extended

periods of drought) 3. the huge cost to develop new water infrastructure

(such as dams and stormwater management systems)

4. the impact of stormwater runoff on the

environment If we are to ensure a sustainable water supply for the future, it is critical that we limit water consumption and develop smarter ways harness our water resources. The shortage of water is not a problem to fix sometime in the future. Water restrictions are in place in many developed communities around the world right now!

The benefits of Rainwater Harvesting

Rainwater Harvesting saves water, money and helps the environment 1. Start saving water now! Rainwater Harvesting

reduces water usage in every household. By installing a complete Rain Harvesting system you will start saving water immediately. Rainwater is the most efficient water solution. Runoff from the roof to the tank is immediate and efficient, whereas runoff in vegetated dam catchments requires significant rainfall to impact on dam levels. You can take control and make a difference today!

2. Safe, sustainable water. Rainwater is naturally

pure and fresh. It is not recycled water. Provided certain precautions are taken, research supports rainwater as a safe, sustainable source of water that can meet all of a household's requirements. Australia is the driest continent on earth, and over 3 million Australians rely on rainwater as their sole supply. Water for drinking and food preparation purposes represents less than 5% of all urban water use. When rainwater is used for the remaining 95% of our requirements, including for washing clothes, flushing toilets, watering gardens and even bathing, many millions of litres of precious drinking water are kept in the dams for when we need it.

3. Significant cost savings – for the community and each household. The cost to supply potable water to the community is increasing. Dams and chemical treatment system cost millions of taxpayer dollars to establish and to run. Many local authorities have started to charge the local community for their water usage. By substituting mains water for rainwater you can avoid these water charges, take pressure of centralized supplies, and reduce the need for huge investments to build new dams and water treatment plants and pipelines. When you consider the total cost to the community, it makes common sense to install a rainwater harvesting system to catch rainwater that falls for free from the sky and utilize it in and around the home.

4. Lower overall water usage. People that collect and use their own rainwater become more aware of their water use and can further reduce their overall water use.

5. Lower energy consumption and greenhouse

gas emissions. There are significant costs to treat and pump mains water throughout the community. Widespread installation of Rainwater Harvesting systems results in reduced energy consumption and less greenhouse gas emissions. Rainwater is an ideal water source for 95% of our requirements, is not recycled and nor does it require treatment before being used.

6. Protect local waterways and reduce

stormwater infrastructure costs. Rainwater from roofs is usually directed into centralized stormwater pipelines that empty in local creeks, rivers and bays. By capturing and utilising rainwater where it falls, Rainwater Harvesting reduces both the volume and velocity of stormwater run off from our urban areas. This helps protect our waterways and reduces the need

for expensive stormwater infrastructure and management systems – another big cost saving.

Main household uses of water A typical household uses over 650 liters of water every day. This equates to around 240,000 liters (or 5 average sized swimming pools) each year! Up to half the water supplied to household ends up as waste water. The main uses of water at an average home are: 1. Watering the garden and other outside uses

(35% or 94,500 liters per year)

2. Flushing toilets (20% or 54,000 liters per year) 3. Showers, bathing and the bathroom (20% or

54,000 liters per year)

4. Laundry use, washing clothes (15% or 40,500

liters per year) 5. Dishwashing and the kitchen (10% or 27,000

liters per year)


Systems and products for Rainwater Harvesting Rain Harvesting has developed a range of products that should be installed with the rainwater storage tank to improve water quality, increase catchment efficiency, protect rainwater pumps and internal household appliances and reduce system maintenance. The products are relatively maintenance free, simple in their operation and help ensure your rainwater harvesting system delivers superior results. Visit www.rainharvesting.com


for more information. Rain Harvesting has also developed the following guidelines to help people design their own complete Rainwater Harvesting system.

10 Steps to Rain Harvesting Sustainable Water The following practical guide, developed originally for the Australian market, outlines some considerations in planning your own rainwater harvesting system.

http://www.rainharvesting.com.au/blue_mountain_all_steel_gutter_mesh.asp

http://www.rainharvesting.com/

How to Create a Complete Rain Harvesting System Don't just fit a tank - install the complete system The following diagram shows the components that form a part of a complete system. Rain Harvesting manufactures many of these components - feel free to visit www.rainharvesting.com for more information.



Water Storage and Tank Selection There are many different water storage options and manufacturers have developed innovative solutions in recent years.

Choosing the size of your tank Things you need to consider when determining the size of your tank or storage vessel include: 1. Rainfall - how much rainfall you get in your area, 2. Roof area - how large the catchment surface is, 3. Water usage - what you intend to use rainwater

for, and how much you expect to use, 4. Site characteristics - how much space you have,

and the location you intend to install the tank or storage vessel.

Calculating the appropriate size Use the following formula: Roof Area X Annual Rainfall = Maximum Available for Capture Then determine: Most Days without Rain X Average Daily Water Use = Storage Volume Required on Day One of a Dry Spell If for example, the most days without rain was 40 days, and the average daily usage was 400 liters, the volume on hand on Day One of 40 days would have to be 16,000 liters. It is very difficult to predict the required volume, because often a dry period will start when the tank is not full. However, this method provides a guideline, and you can add a safety factor on top of this requirement. When calculating how big the storage capacity should be, plan the tank area so that extra storage can be added later if required.

Location for the tank It is important to consider the space you have available, whether the vessel is to be installed above or below ground, below the roof-line or above it (eg. on a sloping site), whether you will have one or more tanks - connected or installed as separate systems, and what ground surface preparation is required

Above or below ground When planning the installation of a rainwater tank, it is important to consider where it can be located on your property. In many cases tanks are installed above ground, especially when the tank is being installed alongside an existing dwelling. Concrete, metal/steel, poly, fibreglass tanks and bladders can all be installed above ground and are a popular option due to quick installation and low cost. Often incorporated as part of the development of new homes, under ground installations are space saving solutions. Concrete or poly tanks for example, can often be installed under driveways, and provide a solid platform for sheds or gazebos to be built on. Ideal for urban areas where the small house blocks prohibits the use of above ground tanks, many concrete tanks are trafficable and can be located under the driveway of the house, with only the access covers visible.

This reinforced poly tank (above) has a storage capacity of 5000

liters.


Tanks can be installed in combination to provide greater storage

capacity. These poly tanks have been installed underground alongside a fence line.

Polyethylene or Plastic Tanks Popular due to their lightweight material which makes for easy site preparation and installation, Polyethylene (Poly) tanks are now the most common for household use and come in a variety of shapes, sizes and colours.


Poly tanks are among the fastest growing types of tanks. They are made from polyethylene which is UV treated, impact modified, and food grade which means it is suitable for potable (drinking quality) water. Corrugated designs are particularly strong profiles by engineering design. Plastic tanks can be placed on a base of cracker dust or sand, and typically come with warranties of up to 25 years. Polyethylene is a plastic that has been around for many years and is a proven product that will not break down in the sun for at least 25 years. Most tanks actually come with a 25 year warranty. As with all tanks there is always the possibility of a manufacturing problem, so it is important for peace of mind to purchase a tank that is accredited with a recognised standard which means the tank is made to "world’s best practice”.

Poly tanks are typically rotary moulded. To make a tank the manufacturer makes a mould from steel, like a big steel canister. The canister is then loaded with plastic granules or powder, closed off and then rotated over a heating source to melt the plastic. When the plastic has melted and the canister cooled down it is opened and there is the tank. The amount of plastic granules or powder placed in the canister determines the thickness of the tank. Some steel moulds for plastic tanks have flanges down the side to make it easier to get the tank out of the mould and tanks made in moulds like this will show a line where the mould joins but it is not a join in the tank. There are a variety of manufacturers of this type of tank around the world and there will be a stockist near you. The shapes of the tanks vary according to the manufacturer. The majority of the designs are computer generated for both strength and appearance but by far the strongest profile by engineering design is corrugated. These designs actually look like a conventional tank and can complement the home and environment well. In recent years manufacturers have developed new modular and slimline water storage solutions.

Suitability Popular due to its lightweight material which makes for easy site preparation and installation. Poly tanks are now the most common for household use and come in a variety of shapes, sizes and colors.

Site Preparation : A base of cracker dust or sand

In Ground : Yes, consult the manufacturer

http://www.rainharvesting.com.au/poly-plastic_tanks.asp

Guarantee : 25 years, ask for the manufacturers guarantee

Repairable : Yes, consult the manufacturer

Metal tanks Metal tanks are extremely strong and many feature food grade polyethylene tank linings warranted for 20 years to prevent corrosion and ensure water quality. They have been popular for years and continued development of new colours, shapes and sizes has ensured they still are. Some years ago they were made from rolled sheets of galvanized iron and riveted and soldered to prevent leaking. They were the backbone of water storage the world over. Now the plain metal tanks are typically made from steel and zinc metal alloys in under trademarks including Aquaplate®.

Metal tanks are also available using a modular construction system which ensures strength, water quality and makes delivery onsite more manageable. These modular tanks can be built to store significant water volumes and are extremely popular in rural and commercial applications.

Suitability Extremely strong tanks with polyethylene tank linings to prevent corrosion and ensure water quality. Site Preparation: A concrete base is required or alternatively an approved tank stand. In Ground: No Guarantee: Ask your supplier for a written guarantee for both the material & the workmanship. Repairable: Yes, seams can be resealed by the manufacturer.

Concrete tanks Concrete tanks come in two types - either delivered complete, or poured on site. Those delivered on site in a complete form are craned off the truck and onto a prepared sand base. These tanks are sometimes in one to three pieces. A two or three piece tank is made up of "two cups" one inverted on top of the other. A three piece tank is the same as a two piece but with a ring section in the middle. The sections are sealed together in a variety of ways depending on the manufacturer, some use a sealing ring made from a rubber or synthetic substance which is placed in a groove of the lower "cup" with some sealant before the top half is placed on. Sealant is then applied to the inside of the tank at the join to stop the water leaking out. Concrete tanks are often poured on site using a steel mould into which reinforcing steel is placed before concrete is poured in. The steel form work is then removed and the completed tank is revealed.


Concrete tanks can be placed either on top or in the ground. Concrete tanks are usually the most affordable for an in ground solution. They are ideal for this purpose because they can be covered with load-bearing lids and can fit under driveways or other structures. Cracking of the tanks is one of the most common complaints but most concrete tank makers have techniques to minimise cracking. Suitability An ideal in-ground solution. Feature load bearing tank lids, so they can be installed under garages or driveways. Site Preparation: Compacted cracker dust or compacted sand, stabilised around the edge In Ground: Yes Guarantee: Ask your supplier for a written one prior to purchase Repairable: Difficult to repair cracks if they occur. Consult the manufacturer.

Fibreglass tanks Corrosion resistant and sturdy, fibreglass tanks are a relatively expensive but long-lasting option. These tanks have been around for many years and were made from the same sort of material as a fibreglass boat, but in recent years glass strands mixed with special resins have been used and the tanks are quite strong and relatively easy to move around on site. Some manufacturers line these tanks with special material to further enhance the life of the tank.

Suitability Corrosion resistant and sturdy, fibreglass tanks are a relatively expensive but long-lasting option. Site Preparation: Compacted cracker dust or compacted cement stabilised sand or concrete pad In Ground: Consult the manufacturer Guarantee: Ask your supplier for a written one prior to purchase Repairable: Yes, consult the manufacturer

Bladders and other innovative solutions New space saving bladders and modular storage systems have been developed in recent years. These water storage vessels provide wonderful solutions, particularly for urban areas.

Bladders have been developed which come with all inlet and outlet pipes required for complete installation. They can generally store between 2,000 and 20,000 liters of water. The sizes and capacity vary according to length and width of the bladders. They are sealed yet flexible, with an enormously high puncture resistance that is designed to be securely located in the sub-floor space in areas as low as 750mm in height (without excavation) and without inducing any structural load to the dwelling.


One criteria in choosing a bladder type is whether it is filled from the top or the side. Those that fill from the side (see photo right) require less space for pipework above the bladder, but either way, bladders are a great solution where you have space constraints.


By placing the bladders under a house or deck, they can collect ALL of the rain that falls on the roof by diverting the ALL downpipes to a common in-flow pipe which goes into the side of the bladder. This means that more rainwater can be collected much faster than in a traditional water tank. Once the bladder or bladders are full, any excess water diverts to the existing storm water system so that there is no fear of over-filling.

If space permits, multiple bladder tanks can be installed either end-to-end or side-by side for maximum storage, as demonstrated in the diagram below. Bladders are typically designed to fill to a maximum height of 600mm.

Some manufacturers use water sac couplings that are compression fittings where the interconnecting pipes are pushed through and clamped tight to seal. This is instead of traditional threaded joints to ensure that a damaged or stripped thread (particularly in a PE tank) does not mean unusable water storage. The bladders are housed in high quality steel frames to keep them in place and this frame is often wrapped in a geo-textile blanket for added protection. The bladders are typically made of a material called Aeon which is well established in the market place.

Suitability

A great space saving option. Ideal for under house or under verandah water storage. Site Preparation: Compacted cracker dust or compacted cement stabilised sand or concrete pad. The area must be clear of rocks, tiles and other debris. Smooth the ground, leaving a slight fall towards the outlet end of the bladder. In Ground: Consult the manufacturer Guarantee: Ask your supplier for a written one prior to purchase Repairable: Yes, consult the manufacturer.

‘Wet’ and ‘Dry’ Systems Rain Harvesting systems require rainwater from the roof to be directed to the water storage vessel through gutters and pipes. These pipework systems will be different at every location, however are classified as either:


1. ‘Dry’ systems, or 2. ‘Wet’ systems

‘Wet’ Systems ‘Wet’ systems are also referred to as "charged" systems and are systems where the pipes from the gutter go down the wall and underground and then up into the tank. Many systems are ‘wet’ because the size of buildings and the placement of tanks away from the buildings mean that there are long runs of pipe underground leading to a riser at the tank. Because the pipes are underground and below the entry point to the tank, even during periods without rainfall water remains in the pipes

Because the water that sits in underground pipes has a tendency to become stagnant and provides a potential breeding habitat for mosquitoes, it is critical to insect proof the pipes in a 'wet' system. Legislation broadly says that where pipes hold water they must be screened with a non-corrosive screen of not more than 1mm aperture to prevent the entry of mosquitoes and vermin. Mosquitoes are known to be responsible for many diseases including Dengue Fever and Ross River Fever. Rain Harvesting has developed a range of products to insect proof rainwater systems, including rain heads,

insect proof screens and flap valves and vent cowls, all of which have been designed to meet all legislative guidelines, including ‘Wet’ systems can be converted to "dry" systems using an In-Ground First Flush Water Diverter which improves water quality and saves water.

‘Dry’ Systems Are systems where the pipe system is designed to run direct from the gutter into the tank. The pipes drain out after rain and do not hold water when the rain stops. ‘Dry’ systems are best because water sitting idle

in pipes can become stagnant and provides a potential breeding ground for mosquitoes.

Both systems have strengths and weaknesses, and with a little planning, you can optimise your water quality and install a system that looks good.

Converting a ‘wet’ system to ‘dry’ Buried and out of site, In-Ground First Flush Water Diverters are perfect for sloping allotments. On a site with a minimum of 5 degrees slope that also provides the opportunity for the end cap of the diverter to be positioned above ground (to drain out and be

http://www.rainharvesting.com.au/mizzie_stoppa_screens.asp

http://www.rainharvesting.com.au/in-ground_diverter.asp

accessible for maintenance), an In-Ground Diverter converts a ‘wet’ into a ‘dry’ system.


By draining the water normally held in pipes after rain, an In-Ground Diverter SAVES WATER, because the next time it rains, the only water that has to be diverted is the amount of water required to flush the roof.

The water that sits in underground pipes has a tendency to become stagnant and provides a potential breeding habitat for mosquitoes. When it rains a "head" of pressure will force this poor quality water towards the tank. Not only can an In-Ground Water Diverter prevent this water from polluting the tank, it will also ensure that after rainfall the water in the pipes drains out through the diverter chamber.

For more information about In-Ground Water Diverters, visit www.rainharvesting.com.


Pump Selection

Distributing water for use around the home There are two main types of pump systems used in typical household systems. There are other pressure vessels systems but these are usually only used on extremely large houses or for commercial applications. To work out the type of pump that is best suited for the purpose it is best to talk to a professional pump dealer. There are many factors which govern the type and size of pump that you will need so that your system will deliver water as you would expect.

Pressure Vessel Pumps Usually work on 20-40psi/140-280kpa. or 30-50/210-345kpa. Variable pressure systems - which means that when a tap is turned on water is drawn and when the pressure is down to 20psi/140kpa. the pump will start up and when the pressure reaches 40psi/280kpa. the pump will shut off. The amount of water that can be drawn off before the pump starts up depends on the size of the pressure vessel. The bigger the pressure vessel, the greater the volume of water that can be drawn off before the pump restarts

Constant Pressure Systems Invariably use the same motor and pump body as the variable pressure system except that a constant pressure control valve system is fitted. These latest pressure control valve systems are simple and effective, efficient and very cost effective


Regulation and Rebates Rainwater Harvesting delivers significant water savings and governments around the world are looking for new ways to reduce the demand placed on centralized potable water supply networks.

Incentives for the community Many provide incentives such as rebates to offset the cost to install rainwater systems. Before you go ahead and purchase your system contact your local authority to see what programs are available. These incentives make installing a complete rain harvesting system even more rewarding.

New standards for Energy and Water Efficiency

Governments around the world are introducing new standards for energy and water efficiency for the construction of more sustainable buildings. In recognition of water savings that can be delivered by incorporating rainwater harvesting into household water supplies, many governments have either made the installation of rainwater tanks compulsory in both urban and regional areas, or provide credit points towards meeting sustainability guidelines.

Rainwater Tank Installation Guidelines Many federal, state and local governments have developed guidelines for how to install rainwater tanks and increasingly Screened Downpipe Rain Heads, First Flush Water Diverters and products that insect proof

systems are becoming mandatory. It is important to consult your local authority about these requirements as they have been prepared not only to ensure your can maximise the amount of good quality rainwater you can collect, but also to ensure public health and safety.

Plumbing Regulations Local authorities may have specific requirements concerning the way in which rainwater systems are to be connected to household supplies. A licensed plumber will be in the best position to advise you of these requirements and it is important to have a plumber complete the installation.


http://www.rainharvesting.com.au/first_flush_water_diverters.asp

About Us – Rain Harvesting Pty Ltd

Our vision Rain Harvesting Pty Ltd is a new company, established in March 2005 following the acquisition of a portfolio of unique products that form a complete water catchment and storage system. Rain Harvesting is a manufacturer and wholesaler of sustainable water products intent on helping people build sustainable futures. Our specialty is water catchment, storage, insect/pest control, and leaf and debris removal systems used in both rainwater harvesting and home protection. Our vision is to be a leader in sustainable water systems, not only providing complete rainwater solutions, but to develop new sustainable water markets, both in Australia and internationally. We are committed to driving innovation and aim to provide a complete system – a one-stop for sustainable water products. We value our stockists as strategic partners in our business. Whether it is product training for store staff, our comprehensive product brochures or retail point-of sale materials, we make it easy for our stockists to sell the benefits of rainwater harvesting to the end-user. When you need us, we’ll deliver. 98% of our orders are delivered to our stockists within 3-5 days. We’re easy to deal with because we believe in building relationships for mutual benefit. We’re driven by your success and are active partners in fuelling category growth.

Development of the product range The Leaf Eater® gutter downpipe rain head was first manufactured in 1992 to prevent the build up of leaves and debris in roof gutters which is the most frequent cause of poor quality tank water. It was the first multiple screen rain head developed, working as both an insect proof water catchment device and a hassle free leaf and debris exclusion system for roof gutters.

After three years of development trials, production began in 1997 of an all steel gutter mesh system now known as Blue Mountain Mesh™.

A complete range of insect proof screens and flap valves, tank overflow outlets and other accessories were added to the range through the 1990’s, prior to the invention of the range of First Flush Water Diverters.


In 2006, the Rain Alert™ was the first wireless tank level monitor launched into the Australian and New Zealand markets.


Contact Us Rain Harvesting Pty Ltd 28-34 Reginald Street, Rocklea, Brisbane QLD 4106, Australia PO Box 311, Archerfield QLD 4108, AustraliaTel: +61 7 3248 9600 Fax: +61 7 3248 9699 Website: www.rainharvesting.com.auEmail: [email protected]


http://www.rainharvesting.com.au/

mailto:[email protected]

harvesting rainwater – a safe, sustainable water source · when planning the installation of a...

Documents