Now that you've passed the test (or checked out the answers) to the the Chasing Water book that I reviewed in my previous blog post, here are Brian Richter's ideas for water sustainability. So what does water sustainability really mean anyway? He cites Peter Gleick of the Pacific Institute who offered this definition: "the use of water that supports the ability of human society to endure and flourish into the indefinite future without undermining the integrity of the hydrological cycle or the ecological systems that depend on it." For example, Richter suggests extracting more than 20 percent of a river's daily flow can lead to ecological harm to fish, turtles, frogs and other sensitive species. Lakes and aquifers may be even more sensitive to withdrawals due to slow replenishment.

Here are seven principles to consider for sustainable water management:

1. Build a shared vision for your community's water future.

2. Set limits on total consumptive use of water.

3. Allocate a specific volume to each user, then monitor and enforce.

4. Invest in water conservation to its maximum potential.

5. Enable trading of water entitlements.

6. If too much water is being consumptively used, subsidize reductions in consumption.

7. Learn from mistakes or better ideas, and adjust as you go.

Western water law based on prior appropriation (first in time, first in right) allows control of senior to junior water rights for people but priorities for sustaining natural ecosystems depends on people advocating for the environment. Obstacles to water conservation cited by the author include challenging social norms (people love green grass even in the desert), water providers whose receipts depend upon sales, spreading fear of shortages, and political will for unpopular projects such as dams. 

Richter explains how he learned through personal connections that Australian landowners fought for the environment even during severe droughts to keep water flowing and prevent additional fish kills. A cap-and-flex system adopted in the Murray-Darling watershed enabled setting limits to priority distributions for consumptive use accounting for protecting ecosystems and being flexible with supply during wetter years. The government stepped in to purchase 400,000 acre-feet at a cost of $700 million to store and distribute water where needed for ecological preservation and areas significant to Aboriginal people. 

Australia set up a market-based system to trade water rights which improved accounting systems for water management such as adding efficient technology that can measure the hydrologic cycle and consumptive use. 

Ultimately, there is great power in creating partnerships that can transcend institutional bureaucracies - individuals in local communities and grassroots organizations can network with public and private groups to share in a common mission to find solutions to these challenging problems.