Sprinkler shut offs under kitchen sink
Get the Building Code in Canada to require a shut off to garden hoses in the kitchen. A timer could cheaply and easily be screwed on/attached inside. Most water is wasted because people are busy and forget to shut if off, or too lazy to go outside and turn the tap off. Requires just an extra piece of plastic or copper plumbing pipe in new or older homes. Saves energy, water, chemical treatments, property taxes, frozen outdoor taps, etc.