Turn off taps when not needed
Running a tap when the water isn’t actually doing anything of value is pretty much the definition of waste. Tap water is treated and pumped to our buildings. When it goes down the drain, it is again pumped and treated. It takes a lot of energy to provide us with water. Water and sewage treatment is a major source of greenhouse gas emissions, due to the energy consumed, and the methane released.
Washing hands, rinsing dishes, and cleaning are some of the times you may be tempted to leave the tap running. Instead, simply turn off the tap. Fill a bucket or a sink to do the job.