This was great news for the Water Harvesting industry - we appreciate the foundation showing leadership in water sustainability - with the million gallon cistern and the green roofs! That's a big investment, but it will pay back year after year after year for the foundation and their community.
They built their system with a concrete vault system - but we are excited about a more efficient and cost-effective system for water storage using recycled plastic rain tanks that are buried under ground. You can read about the Atlantis D-Raintank system at this link:
About Water Storage Options That system is totally flexible in shape and size from a few gallons for a homeowner to millions of gallons for a commercial application like the Gates Foundation.