"I understand that.. but where would I start to see if I could even do
it... seeing as how the greenies might now want me running my water
over
the edge of the ravine... "

I'd start by getting one of the neighbors to say that they will let you
do it. Then, I'd go to the local code/building dept and ask them what
regulations apply and what approvals you would need. Next, I'd get the
permits/approvals and then, I'd have a lawyer draw up the easement
documents and get them signed. If it turns out the permits/approvals
would involve more than a couple hundred bucks, then I'd get the
easement first.