A rainwater tank collects and stores rain water, typically from rooftops via rain gutters. A typical rainwater collection or harvesting tank can yield 2500 litres of water from 25 mm of rain on a 100 m2 roof.
Rainwater tanks are installed to make use of rain water for later use and reduce CWA water use for environmental reasons.
Stored water may be used for watering gardens, agriculture, flushing toilets, washing machines, washing cars, and also for drinking.
If rainwater is used for drinking, it must first be filtered using a Bio UV Filtration system which will remove bacteria, chemicals and most pathogens. While rain water is pure it may become contaminated during collection. Thus, we strongly advise not to use rainwater for drinking when there is an alternative mains water supply available.
Rain water harvesting is an environmentally sound and responsible practice in today’s context of environmental protection.
Rain water tank main features:
- Manufactured from 100% virgin material
- Moulded in-one-piece design
- Screwed cover
- Can be fixed at ground level and underground
- 12-year guarantee
- Opaque design
- Availability of special custom modifications. Ex: additional inlet float valve, variable height outlet, level indicators, outlet and overflow curves
- Manufactured from Food Grade materials
- UV stabilized
- No taste or odour imparted from polyethylene
- High impact resistance
Step 1 – Establish Rainwater Harvesting Capacity
- Determine roof area
- Determine average rainfall per week from Mauritius Bureau of Meteorology
- Calculate tank capacity by multiplying roof area and average rainfall per week
For example, a roof area of 100 m2 with an average rainfall of 25 mm yields 2500 lts (100 m2 x 25 mm = 2,500L). Required tank capacity = 2,500L
Step 2 – Based on the capacity of storage, you can select from the different models available
- Duraco conventional Rain Water Tank - 450 Litres to 2000 Litres
- Column Type Rain Water Tank – 350 Litres to 500 Litres
- Integrated Filter Type Rain Water Tank: 2500 L to 9000 L (Patented model)
- Decorative Rain Water Tank – 350 Litres to 500 Litres
- Underground Rain Water Tank – 4700 Litres
Step 3 – Selection of accessories for Rain Water Harvesting
- Super head filter
- Water pump
- Level Indicator
Step 4 – Preparation of Site to accommodate Rain Water Tank
- Ensure the tank is placed on a solid and levelled concrete base.
- The guttering on your roof is also a key component in your rain harvesting system and will need to be cleared of any leaves or debris. Damaged guttering should be repaired. Sometimes guttering may also need to be adjusted to direct the water to the corner of your house where the tank is installed.
- Tank overflows must be designed to ensure storm water does not pond under the concrete base, the building floors or flood around foundations and footings of buildings.
Step 5 - Distribution of the rain water
- Diverts first 60 litres of rainfall to ensure cleaner supply
- Select a pump and filtration system to distribute water for use inside or outside the home.
- Plumb tank to your washing machine, toilets or outside gardening tap.
Super head Filter
The Superhead filter combines four essential filtration functions into one simple device to automatically filter the rainwater entering your water tank. The four functions are:
- Rain head to channel water from downpipes into the rainwater tank
- First-flush diverter to automatically flush the first rain from washing pollution off your roof and into the tank
- Leaf screen to prevent leaves blocking pipes and entering the tank
- Insect guard to prevent insects entering the tank
In short, it prevents dirt, dust, leaves, insects, rodents and bird droppings from flowing directly into your rainwater tanks every time it rains. The Superhead rainwater filter rotates 360 degrees and can either be mounted directly to some water tanks or on the wall and is suitable for both side and top inlet tanks.
The adjustable drainage plug which is attached to the bottom of the flush pipe is designed to slowly drain the dirty/polluted flush water. This means that in the event of frequent rain, the system does not need to do a full flush every time, maximizing the amount of water that you collect in your tanks while ensuring that the water entering the tanks is clean.
- Includes 80mm / 110mm adapters
- First flush diverter
- Adjustable drainage plug
- Stainless steel leaf screen
- Insect screen
- Easy to install, low maintenance
- Made from top quality UV protected PVC
- Can be painted
- 10 Year guarantee.
How does the superhead filter works?
- Polluted water is washed from the roof and gutters and enters the top of the superhead filter
- Leaves and large debris are filtered by the large leaf screen and simply fall off the screen
- The polluted water is automatically diverted through a one way funnel to the flush pipe. When the flush pipe is full, the roof will be cleaned. The water coming off the roof is now clean and overflows into the tank. Any small particles are trapped by the one way funnel.
- A fine filter in the outlet pipe will filter any floating debris and prevent insects from entering the water tank
- The polluted water slowly empties through the adjustable drain plug at the bottom
Duraco Rain Water Tank with Integrated Filter – How it works?
- Rainwater is collected from the roof via the gutter (1).
- Before entering the storage tank, the water is Pre-filtered, (2) where large particles such as leaves, moss, animals feces and twigs are separated.
- The Pre-filtered water is fed into the storage tank via a Foam Filter (3) where the small particles are collected. The purpose of the Foam Filter is to significantly cut down on Maintenance by preventing organic buildup in the tank, thereby decreasing microbial food sources.
- Water Passed through a calmed inlet system (4), thus ensuring that the water inside of the tank stays calm and sediment can settle to the bottom or float to the surface.
- The water is then pumped to the serviced appliances via a floating extraction device (5) which always takes the water below the surface and above the bottom of the tank. The floating extraction device has another filter to avoid suspended matter entering the supply.
- An Overflow Mechanism (6) are included in the Rain water Harvesting system design in order to remove sediment in the Anaerobic zone of the tank. The Duraco Rain Water Harvesting tank is Opaque and protected from direct sunlight to inhibit algae growth and screened to discourage mosquito breeding and reproduction. The tanks are also UV treated and impact resistant.
Requirements and the flush volume:
- It is recommended that you flush a minimum of 20L per 100sq/m of roof catchment area.
- A standard installation is usually between 14L-20L depending on the rate of drainage, however this can be increased by installing more than one Superhead.
- If you live close to trees or in an area where you are likely to have more pollution on the roof, then we would recommend that you install more than one Superhead, to increase the flush.