The Rainwater HOG is available in Ontario. Modular by design, it holds the most water in the least amount of space. Best of all it can be added onto over time to increase rainwater capture.
Graywater systems can save a household 35-40% on water costs. As more municipalities address increasing water pressures, a graywater system can help save a homeowner money and reduce pressure on municipal systems. But, it can only be installed in certain situations.