There are a variety of systems on the market but the general concept is always the same:

 

• The water is first filtered and then stored.
• Water is then pumped either directly to the points of use or to an internal break tank.
• If the system runs low on rainwater a mains water back up unit will guarantee continuous supply feeding mains water into the systems..
• When it rains again, the system changes automatically back to the rainwater supply.

 

Diagram illustrating layout of a rainwater harvesting system:

 

Typical system components are:

 

• Filtration – depending on contamination of the water and on requirements, different methods of treatment are used, but always a pre-storage filter employed.
  
• Storage – to balance water yield and consumption. Different material are used; plastic, GRP, concrete
• Technical components – pumps, controls, mains back up
• Overflow – storage has an attenuation function but secure drainage is needed to soak-away or storm drain.

 

Note: At the point of use separate pipe work is needed in order to avoid potable water and non-potable water coming into contact.

 

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 seperate out the drinking (incl. bathing) water from the non-drinking water (WC, washing machine & outside tap.)

 

Maintenance

 

Rainwater systems are relatively easy to maintain. If the tank is overground it is easier to maintain in case there is a change of scenario or pump failure. A filter installed in the down-pipe to the tank is a good addition for all tanks but is particularly to be recommended for larger tanks installed above ground where water may be stored for a longer time. It will help prevent water becoming smelly by removing leaves and other debris. This also stops sludge accumulating at the bottom of the tanks, and tap outlets, hoses and water-can heads clogging up. Some filters separate debris out and send it on down the drainpipe. Other filters eject debris straight out the side, while cleaned water goes into the tank. Both kinds are easy to maintain.

 

Please feel free to get in contact with us by email or call 0845 189 9894 to discuss any of your requirements.