The world's first really green oil deal

In early March Ecobuild attracted businesses and visitors from all over the world to Earl's Court in London to learn about and discuss the latest trends in green building and construction.  Some of the buzz at the show surrounded a recent decision by the UK government to increase the Feed In Tariff on renewable energy.
The decision by the UK government is likely influenced from the now farther progressed renewable energy market in Germany where they incorporated a high-paying Feed In Tariff early on.  But, whilst strolling around the Ecobuild show I couldn't help but think that perhaps there is an industry being ignored that could provide a service every bit as important to Brits.
The industries I speak of are rainwater harvesting and green roofing.  In a nation ravaged by floods and with absolutely no lack of rain, these industries provide a product with many advantages to the purchaser as well as local and federal governments.
For those of you who may not be aware of such industries they are exactly what they sound like.  Rainwater harvesting is a system of collecting rainwater and storing it in tanks to use for any number of functions from toilet water, to washing laundry and if purified, for drinking.  Green roofs are roofing systems that allow plants to grow on your roof from small greenery and wild flowers up to full trees.  Green roofing contributes to a building's insulation, helps reduce CO2, and critically reduces the strain on storm water systems by slowly leaking the water from it's soil and substrate layers.
Perhaps looking at the problem of flooding and the ample supply of rain received in the UK, it would be in the governments interest to supply a tax incentive for households and companies to implement these types of products on a wide basis to help relieve the burdened storm water systems.
Give us your feedback and tell us if you think the government should support a move to incentivise rainwater harvesting and green roofing.