In 1951 the State Library of Michigan, then in the Cass Building, was set on fire. State workers rushed to save as many water logged items as possible. In the picture above Michigan Department of Transportation workers are using irons to flatten maps. The recovery efforts were featured in Life Magazine.
Actually, freezing waterlogged books & papers is about the best thing you can do to stop mold and disintegration until someone can deal with the items. The fire happened during sub-freezing temperatures. Nowadays when library items are soaked from sprinkler systems, we rent giant freezers to hold things until they can be worked on. Here it was either a happy accident or workers knowledgeably jumped on cooperative weather.
See the full article starts on page 59: https://books.google.com/books?id=v0sEAAAAMBAJ&source=gbs_all_issues_r&cad=1
A vintage photograph website pulled out the photographs separately http://www.vintag.es/2017/04/pictures-of-book-rescuers-in-1951.html
If your governmental unit or regional planning commission has paper maps and documents worth saving, consider passing them along to an Archive or Library.