
Before I go too far, there are a number of good resources out there on the subject. I'll include those that I have found most helpful in understanding the intent behind the observance:
The World Water Day 2010 and its campaign is envisaged to:
- Raise awareness about sustaining healthy ecosystems and human well-being through addressing the increasing water quality challenges in water management and
- Raise the profile of water quality by encouraging governments, organizations, communities, and individuals around the world to actively engage in proactively addressing water quality e.g. in pollution prevention, clean up and restoration.
- World Water Day 2010: The official site for WWD 2010, and a great place to start. While the events that are listed have finished, it would be worth looking into some of the photos that starting finding their ways back here from those events.
- World Water Day - Wikipedia: The Wikipedia entry on the event, with info about past years' themes and links to even more useful resources.
- UN-Water: The official website of UN Water, and "inter-agency mechanism" for collaboration on the subject of water for UN agencies, and the group responsible for WWD.

Despite the world’s population being almost equally divided between urban and rural dwellers, the vast majority without access to water and sanitation live in rural areas. Seven out of ten people without basic sanitation are rural inhabitants and more than eight out of ten people without access to improved drinking-water sources live in rural areas.

BioSand Water Filters are a technological adaptation of the centuries old slow sand filtration process. While implementations exist in many different sizes and varieties, the most common design is intended for use in rural homes where naturally safe or treated water sources are not available.
BioSand Filters remove 95.0 to 99.0% of organic contaminants, including bacteria, viruses, protozoa, worms, and particles. Safe water produced by the filters is free of discoloration, odor, and unpleasant taste, and can be used for drinking, food preparation, personal hygiene, and sanitation. Most common home-based models can produce between 20 and 60 litres of water per hour.
While it's easy to feel guilty about wasting water for the sake of art, I found myself feeling that I could at least do something to offset my waste, much in the way people offset their carbon footprints. I didn't find any sites specifically for offsetting your water wasting habits, but I did happen upon Charity: Water. With a little browsing, I found my way to their Unshaken program, which specifically provides clean water resources to survivors of the quake in Haiti.
A quick $30 donation there didn't mean much in the greater scheme of my own finances, but it will mean a year's worth of clean water for someone displaced by the quake in Haiti. At the very least, I will feel a bit better the next time I end up using clean water for shots like this: