Comprehensive workflow that shows how to simulate a flooding of a site, from a river and inside of the site.
Analysis bases on Global Mapper software and SRTM elevation model
For Global Mapper
https://www.bluemarblegeo.com/products/global-mapper.php
For SRTM elevation model
https://www.usgs.gov/centers/eros/science/usgs-eros-archive-digital-elevation-shuttle-radar-topography-mission-srtm-non?qt-science_center_objects=0#qt-science_center_objects