Federal Emergency Management Agency (FEMA)
100 year floodplains have been mapped for the communities listed below and can be ordered for a nominal fee from the FEMA website. 100 year floodplain determinations have not been made for the other communities in Allegan County and no maps exist.

• Casco Twp
• Douglas Village
• Ganges Twp
• Gun Plain Twp
• Heath Twp
• Holland City
• Laketown Twp
• Lee Twp
• Manlius Twp
• Martin Village
• Monterey Twp
• Otsego City
• Otsego Twp
• Plainwell City
• Saugatuck City
• Saugatuck Twp
• Wayland City

National Oceanic and Atmospheric Administration (NOAA)
All kinds of weather information and historical climate maps and data are available.

United States Census Bureau
All kinds of census data and maps are available for download from the census bureau's website.

United States Geological Survey (USGS)
Use this site to order the topographic map you need direct from the USGS. They also have a wide variety of digital data for download.