I cannot speak to nation wide because I am not appointed with them, however, I can say that the comprehensive form (other than collision) does cover water damage from floods.
There is a caveat: if you live in an area that is susceptible to hurricanes or floods frequently there might be a sub-limit or exclusion to flood damage. You will have to examine your policy to make sure you do have flood coverage under your comprehensive section if you live in such an area.
There is a caveat: if you live in an area that is susceptible to hurricanes or floods frequently there might be a sub-limit or exclusion to flood damage. You will have to examine your policy to make sure you do have flood coverage under your comprehensive section if you live in such an area.