There are many free resources to assist you with salvage and recovery after flooding.
BE CAREFUL WHEN ENTERING FLOODED SPACES:
FEMA Coming Home After A Flood – http://www.fema.gov/media-library/assets/images/114335
FEMA Debris Removal Guidelines http://www.fema.gov/media-library/assets/images/110554
IMMEDIATE FREE PHONE ASSISTANCE:
The National Heritage Responders have a hotline to report damage and request assessments: 202.661.8068. This is monitored 24/7, and provides free consulting to any arts or cultural organization in emergency regarding things like costume/set/prop salvage, paper records salvage, digital salvage, etc.
Phone assistance for collections salvage: https://www.lyrasis.org/LYRASIS%20Digital/Pages/Preservation%20Services/Disaster%20Resources/Disaster-Assistance.aspx
FEMA and the Heritage Emergency Task Force have two guides for salvaging personal treasures after fire or flood – which can certainly apply to artistic assets: http://www.fema.gov/media-library/assets/documents/113297
Emergency Salvage of Wet Books and Records
Salvage at a glance
Salvage procedures for wet items
More resources are listed at https://www.lyrasis.org/LYRASIS%20Digital/Pages/Preservation%20Services/Disaster%20Resources/Response-and-Recovery.aspx