With what is being called the first significant El Nino storm of the year bearing down on the southwest US it is time to think about how GIS can support your mitigation, planning, response and recovery needs in local governments. Hopefully you are already doing a lot of this work and leveraging GIS to support it.
Key datasets for your work are inundation layers which will define the areas that will be inundated during certain levels of flooding, and which allow you identify the actual water depth in different areas. With these layers and web apps, staff and the public can be quickly informed of where a given rain/flood event will have impacts.
This is key to an agency to be able to quickly identify the assets that need to be moved or protected, to know where vulnerable populations are in the impact area so they can be evacuated, for staging responders, for gathering damage assessment information post-flood, etc, etc, etc...
Esri can help. With ArcGIS for Flood you get multiple inundation layers based on best-available data, and onsite professional services support and knowledge transfer to configure eight or more web apps for staff and to keep the public informed.