There are many options available for individuals to employ in order to improve access to safe and clean water for everyone. One important starting point is creating dialogue with family, friends, and local government about residential water waste.
Video Summary: Improper use of water at the residential level increases the amount of urban pollutants in the ocean.
A few more tips for individual and community-level action:
Replace lawns with plants suitable for the local climate. Using recycled water may also be a good option to reduce water use. 
Encourage schools and businesses to implement technologies that limit water usage.
Support local river non-profits to ensure fresh water for the community.
Eat locally grown food, and avoid beef and other water-intensive foods.