Solar hot water: http://en.wikipedia.org/wiki/Solar_hot_water - For high water usage, these systems get cost effective fast. This means that if you have 3 teenagers on sports teams, these systems will be cost-effective fast. If it's just the two of you, then look at the numbers. Key point - ask what parts of the system will need to be replaced in how many years, and how much the replacement will cost. The savings for any part of your home will be in life-cycle costs.

Energy Star has a website, and if you go to the Appliances section they will show what the current best appliances are: http://www.energystar.gov/index.cfm?c=products.pr_find_es_products For example, buy a dehumidifier with the least watts per quart removed. The cost of operating a dehumidifier is waaaaay more than the cost to buy one. And, run the dehumidifier off a humidistat, so it shuts itself off when possible. There's LOADS of good information on this site.

If you are on a well and a septic system, then you should go right to the front-loading washing machines. These use the least water, which means they need less soap, then they spin the most water out so you need less time to get them dry - and less water goes to the septic system. These machines are a couple hundred dollars more in the first cost - but the cost break-even point is under a year for those on the well and septic system.

For stormwater issues, http://www.cleanwaternj.org/inhome.html or http://www.rcdsantacruz.org/media/brochures/pdf/HomeDrainageGuide.v25.pdf are the sites listed in the Graphic Handbook. The town of Harpswell has a great site with good ideas: http://www.harpswell.maine.gov/index.asp?Type=B_BASIC&SEC={FA81F206-533D-437E-A7BC-09C82D763D48}&DE={561675BB-7E8F-4D84-9C29-463A057C33E3}.

And, of course, buy local beef - feed lots for beef cattle are huge water users. Local also applies to vegetables and fruits.