NOAA has released a very useful and concise (26-page) guide explaining, step-by-step, how to get the best coastal inundation data for your community, and what you can do with it. From the introduction:
Mapping can be a very important part of understanding inundation issues and preparing for the assessment process. Inundation mapping can be viewed as a four-step process. These steps are detailed in the following document.
Obtain and Prepare Elevation Data:
Elevation data (including bathymetry) serve as the base data layer for mapping coastal inundation. Before using elevation data for inundation mapping, it is important to understand requirements and specifications of the data, how to assess the quality of the data, and where to obtain the data. This section answers the following questions:
What type and quality of data do I need? Where can I find elevation data? Are the data I have appropriate? How do I create an elevation surface?
Prepare Water Levels:
To map inundation, a water surface must be generated. That surface can be based on model output or a single value. Different models and approaches to modeling an inundation surface are discussed in this section, which answers the following questions:
What type of water surface do I want? What steps are necessary to prepare water levels?
With a digital elevation model (DEM) and water level information, geographic information systems (GIS) processes can be used to create layers that represent inundation extent and depth.
How do I model the water surface?
Visualizing the data is important for assessing exposure and impacts, and serves as a powerful tool for education and awareness. Visualization may range from simple maps to interactive Web viewers.
Technical enough to be useful, general enough to not require an advanced degree in GIS-technology. We’ve added it to our Finding and Using Additional Hazard Information page. You can download the Coastal Inundation Mapping Guidebook from NOAA’s site (PDF, 1.4MB).