As you know more, pass it along to others in email, letters to the editor, friends and people you meet, anywhere and everywhere, and learn from them at the same time. Best is to become expert enough on some aspect of your watershed and participate in any stakeholder or other decision-making processes. State, federal and local agency public processes are biased towards those who know the most about an issue and have the most information. Become one of those people yourselves. Get involved in the watershed group where you live.
Every place is in a watershed.
If there isn't already a river or watershed organization, help start one. Help get like-minded people to vote on Election Day. Your efforts on a grassroots level make a difference. And consider running for office yourself some day. There are few better ways to serve your community and country.