Flood gauges might seem like old news, but having sensors that do more than report back to a center might be possible as sensors continue to be improved. We've had the IoT in one form or another with SCADA systems. See this, "SCADA (supervisory control and data acquisition) is a category of software application program for process control, the gathering of data in real time from remote locations in order to control equipment and conditions. SCADA is used in power plants as well as in oil and gas refining, telecommunications, transportation, and water and waste control."
I'm sure there are technical differences between SCADA and the IoT, but we will be able to do many more things remotely and assemble data quickly to help us in reacting to disasters and gaining and maintaining situational awareness. Of course, the threat of cyberintrusions into these systems will remain very real. It is therefore a double-edged sword.