Methods of RWH

Surface run-off and Rooftop harvesting are the two methods that rainwater can be harvested in commercial buildings. The downpipes and the channels that collect the water are the major components along with the filters and finally the storage tank (existing or new can be considered for storage). It can provide non-potable water to meet various needs of commercial buildings such as toilet flushing, laundry, gardening and etc. Several commercial buildings are equipped with sewage treatment systems that recycle grey water back for usage. Combining the RWH and treated water system, commercial establishments can look at reducing their dependence on water supply to just 30%.

Benefits

Reducing the dependence on water is just one of the many benefits of the RWH system. There are several other benefits linked to creating a Rainwater Harvesting system, such as

• Commercial buildings have concrete open surfaces causing the water to run off and, in many cases, flooding the complexes. This can be reduced by redirecting the water to the rainwater harvesting channels that would remove the excess water into a storage tank.
• RWH is a low energy method and does not require any electricity to run. Even the filter systems are easy to maintain.
• There are several building guidelines given for conservation and green buildings today and RWH is on of the major factors.
• Saves money on water bills
• Replenishes groundwater for usage during the dry months
• It is an easy to install and operate system
• Rainwater is landscape friendly as it is free of chemicals
• Drought situations are predicting in major cities in the coming years and RWH is the best solution to handle this predicament
• For commercial rainwater harvesting, larger sites tend to enjoy a quicker return on investment that makes it well worthwhile for industry and substantial commercial developments.

Commercial Rainwater harvesting across the world

Rainwater Harvesting is not just a solution for the problems that cities in India are facing. Fresh water crisis is a common factor for all major cities and many of them have adopted RWH methods in both residential and commercial buildings.

• Singapore has low land resources and hence it dependent on rainwater harvesting to meet its citizens needs. All buildings use rainwater harvesting for their water needs.
• Japan has introduced rainwater harvesting to all the large commercial buildings and is harvesting rainwater on a very large scale today.
• The DaimlerChrysler Potsdamer Platz in Berlin collects rainwater from its 32,000 sqm rooftop off 19 buildings.
• The Museum of London collects 25,000 litres of water every year from its 850 sqm roof.

There are many such examples from schools, commercial car dealerships, large factories and even high-rise buildings.

Rainwater harvesting reduces our carbon footprint and helps in running sustainable commercial operations instead of being dependent on the main city water supply all the time.