By littering, throwing waste into water, flushing them down the toilet and rinsing them down the sink.
Never throw rubbish away. Always look for the correct waste bin. Use water wisely. Don't keep the water running if your not using it. Also don't throw chemicals, oils, paints and medicines down the sink drain or toilet.
Organizations and counsels are working to educate; protect, restore water ways and practice on how to help keep waters from contamination and also preserve water ecosystem from destruction.