I'd love to see the government (or just some kind of NGO) hand out radios and some kind of specific-to-this-community application to people who own boats or other specialty equipment. If there were an easier way to organize, they could be even more effective. Use GIS to let them do site surveys and maybe respond to low-risk rescues, letting professionals/government do the highest risk. Right now there are coordination issues.

(The other thing I'd like to see, which is done in some areas, is turning gas stations into disaster fortified base stations -- they have fuel tankage already, add generators to pump when the grid is down, and maybe store a connex or two full of bottled water and other disaster supplies on property, or in an underground tank type thing (which they already need to have installed for fuel, so whenever they upgrade from single to double wall or whatever, dig one extra vault). Putting a cell tower onsite, and maybe some kind of satcom backhaul, and some kind of data network which could work even in isolated mode, would help in situations like Puerto Rico. The incremental cost of funding this with tax money would be far lower than building up other community response sites.