In charting the future of the Clark Fork River, lessons exist on Blackfoot, Bitterroot rivers

Israel has grappled with crippling drought for years. But people have learned to use Mediterranean sea water and recycled wastewater to provide the country with enough water for all its needs.

Overall, Cambodia is a relatively poor country whose residents don't own much. Norwegian hotel owners in the city of Krong Siem Reap urge their Cambodian staff to be more in charge of making their own decisions by making them co-owners of the hotel, an act that forced them to have more confidence and critical thinking skills.

After the drought hit Australia in the early 2000s, city officials had to start thinking seriously about ways to conserve and creatively store their water. External tanks became the solution, storing rain runoff to create an available source of water for Melbourne residents. This solution may not fit every location, but there are other teachable lessons such as taking radically shorter showers.

Laws in Texas and New Mexico, both locked in the grip of a crippling drought, don't do much to actually encourage citizens to conserve water. New conservation laws and financial incentives are trying to change that.

Farmers in Vietnam face rising sea levels but rejected the city's water engineering projects. They prefer gradual measures to cope with climate change so scientists have allowed the farmers to steer the conversation.

Louisiana and Vietnam both need affordable solutions to rising sea levels. Leaders from Vietnam visited Louisiana to compare ideas.

Most insurance companies avoid insuring poor farmers because the transaction costs are too high, but a non-profit in Kenya created a sustainable way to cover them.

The non-profit Root Capital created a lending initiative in Mexico which helps mid-size rural farmers gain access to capital, skills, and consumer markets from which they would otherwise be excluded.

Clean water and healthy ecosystems are becoming increasingly difficult to come by. With floating islands and other inventions, eco-entrepreneur Bruce Kania thinks that biomimicry - such as reconstructing wetlands and growing biofilms - can tackle the toughest of water problems.

Ecological toilets that use natural composting to break down waste are simple to construct, waterless and are easy to fix. But as philanthropists are finding, getting these to those that need it most is harder than anticipated.