How to reduce the amount of new water sent to & water taken from buildings?

Singapore International Water Week 2012, TWN interviewed Barry Porter, CEO Nubian Water Systems:

"The topic of decentralized water treatment and management, is something that I'm pretty passionate about. I'm hearing more and more people talking about the need to solve two fundamental problems; How can we reduce the amount of new water being sent to buildings, and how can we reduce the amount of water that is being taken away from buildings?

I think it's a topic that needs talking about, a lot of thought, a lot of ideas, and a lot of advocacy. I've started this group called Decentralized Water Management, and I encourage you to join, share your ideas, share your thoughts, share your opinions, and come and be a part of the program"

You can join the group here: https://water.tallyfox.com/groups/decentralised-water-management