Stewart Brand (of Whole Earth Catalog fame) had some http://www.worldchanging.com/archives/004327.html after the California earthquake of 1989. They don't all apply to flooding or wind events but he lists these lessons learned:

What Rescuers Learned
- Right after an earthquake, nobody?s in charge. You self-start, or nothing happens.
- Collect tools!
- If you can smell gas, turn it off.
- After an earthquake, further building collapse is not the main danger. Fire is.
- When you see a fire starting, do ANYTHING to stop it, right now.
- In any collapsed building, assume there are people trapped alive. Locate them, let them know everything will be done to get them out.
- Searching a building, call out, "Anybody in here? Anybody need help? Shout or bang on something if you can hear me."
- Give people who are trapped all the information you've got, and enlist their help. Treat them not as helpless victims but as an exceptionally motivated part of the rescue team.
- Join a team or start a team. Divide up the tasks. Encourage leadership to emerge.
- Most action in a disaster is imitative. Most effective leadership is by example.
- Bystanders make the convenient assumption that everything is being taken care of by the people already helping. That's seldom accurate.
- If you want to help, ask! If you want to be helped, ask!
- Volunteers are always uncertain whether they're doing the right thing. They need encouragement - from professionals, from other volunteers, from passers-by.

He also suggested strongly that first responders should see "civilians" as members of the team and assume a leadership, but not a substitute role. "Everything's ok, the police are here" doesn't work in a widespread true emergency.