Rainwater Tank System: Useful Tips in Harvesting Rainwaters

Rainwater harvesting simply collects the rain which fall onto roofs, then stores it in a tank until required for use. When required, the water is then pumped to the point of use or to a secondary tank (header tank or break tank), thus displacing what would otherwise be a demand for mains-water. In the process, a volume of water is kept out of the storm-water management system, thereby helping to reduce flooding risks. Rainwater harvesting is not a new concept; however, over the last century its use has diminished with the availability of a clean, inexpensive and reliable water source through the mains supply.

More recently, water demand has started to exceed supply, and localised flooding has become an issue. Industry experts are now recognising the important role that rainwater harvesting (also known as rainwater recycling, and greywater recycling) has to play in alleviating both these problems. With strategic water planners looking to reduce the amount of water consumption per head going forward. Solutions such as rainwater harvesting will play a critical role. Rainwater is captured from the roof(s), and brought to a central point, via normal guttering and down-pipes, to enter a storage tank (frequently underground), where it is filtered on entry. A highly efficient and reliable submersible pump delivers the water to a service on demand. Depending on the circumstances a secondary tank (header tank) can be used to gravity feed the water to the point of use.

The size of the storage tank is determined by considering the amount of water available for storage (a function of roof size and local average rainfall), and the amount of water likely to be used (a function of buildings occupancy and function). It is very important not to over-size the rainwater tank too much. An over-sized tank may result in a lower than expected quality of water.
Considerations for fitting a rainwater collection system to an existing property

• The external drainage from the roof needs to be modified to bring the water to a central point.
• Access for the tank and excavation is required.
• Internal plumbing is usually required to be separated out from the drinking (incl. bathing) water from the non-drinking water (WC, washing machine & outside tap.)

Get Benefited With Rainwater Tanks

In the past, rainwater tanks were a common feature of the Australian landscape, but they’ve almost disappeared from our cities now. The majority of Australian households get their water from a reticulated supply. In the 1990s, 16% of households used a rainwater tank and for 13% it was their main source of drinking water.

In recent years, however, the long-lasting drought in many parts of the country and widespread water restrictions have drawn attention to water conservation issues and put rainwater tanks right back onto urban agendas. Many local councils, water suppliers and state governments have been encouraging residents to install a rainwater tank, usually with the offer of a rebate.

The potential benefits of installing a rainwater tank are plentiful, and you don’t need to live in a wet or tropical area to reap them. South Australia, the country’s driest state, has the highest rate of rainwater tank usage. More than half the households there have one, and for more than a third it’s their main source of drinking water., With a rainwater tank products, you’ll:
1. Collect most of the rain (around 80%) that falls onto the areas of your roof you have connected to gutters and downpipes into your tank. For example, if 10 mm of rain falls on to 100 m2 of roof you’ll ‘harvest’ about 800 L of rainwater. That’s about as much as an average Sydney household of three would use in a day if they made no efforts to save water. If they did, they’d get their consumption down to around 500–600 L a day.

2. Reduce your consumption of mains water and, in the long term, cut your water bill. Your water supplier may be able to give you an indication of the savings you can expect.

3. Lower your impact on the environment by reducing your demand on mains water as well as the amount of stormwater runoff into rivers and oceans.

4. ‘Harvest’ water that tastes better and is generally less salty, which is better for appliances and plants.

Ways to Install Rainwater Tanks

Rainwater tanks are an eco-friendly device used to store rain water runoff collected by the gutters on your roof. During a half-inch rainfall, a 50-gallon rain water tank can fill up. This water is safe for outdoor uses such as watering gardens and lawns, washing tools or keeping compost bins moist. Storing rain water reduces your domestic water bill and city's water demands and also helps the environment by conserving water. Rain water tanks are available for purchase at your local garden center; alternatively, you can modify a plastic drum to serve as a rainwater tank system.

Instructions:
1. Clean the rain water tank with a mixture of 1/8 cup bleach and 5 gallons water.
2. Drill a 15/16-inch hole near the bottom of the rain water tank for the drain hole, and insert a 3/4-inch spigot. Make sure the hole is far enough off the ground to attach a garden hose or fill watering cans.
3. Lay a secure cinder block foundation underneath the downspout next to your house. Layer blocks in a crisscross pattern if more than one layer is needed for added support.
4. Place the rain water tank on top of the foundation.
5. Cut the downspout with a fine-toothed hacksaw, leaving enough length to allow the downspout to reach the top of the rain water tank.
6. Attach one end of the flexible downspout extender to the downspout previously cut and the other end to the opening on the top of the rain water tank. If the tank does not have a hole in the top, drill a hole large enough to insert the downspout extender.

Choose Undergorund and Backyard Rainwater Tank

Rainwater tanks can be placed anywhere you want them to be, provided it is conducive to its working. It is of utmost importance that the inlet is right below the guttering if you want to harvest rain water from the roof. You will find many different shapes of tanks which can be placed either above the ground or under it.

Torrential rains and extreme heat and cold may have an adverse effect on tanks installed above the ground; they can catch fire or get damaged during heavy showers and strong winds. When rain water tanks are installed below the ground, roots of trees can hamper its structure and also contaminate the water, this quite naturally is not an issue with above the ground rain water tanks. You can opt for rainwater tanks that are uncovered if they are installed above the ground but not in ones installed underground. It is not safe and has the risk of soil, faeces, pesticides entering it during rains as surface run offs. Installing above the ground rain water tanks is much easier and doesn’t require excavation as in the case of rain water tanks installed below. Maintenance of poly rain water tanks above the ground is much easier as well.

Weigh out all your options before installing your rain water tank. You also have the chose the type and shape of the tank. You can choose between steel, wood, concrete, fibre glass and polyethylene (poly) water tanks. There are also many shapes you can choose from. There are round tanks that are very popular all over the world and that can hold a large capacity of water. You can also go in for the slimline tanks that are great on the side of a wall and behind the house. You also have rain water tanks that are ornate and specifically designed to add to the façade of the house and many more to chose from.