I've looked into this as well.
Only a few in the market that's good esp in van.
Blondo 'Valerio' Waterproof Boot (Men) | Nordstrom
Cole Haan has them too but they aren't really "water proof" like gortex; they are their Warren Waterproof Chelsea edition shoes.
http://www.colehaan.com/warren-water...proof&start=14
for really low budget: Essential Details Waterproof Slip On from Rockport.
Yes weird name but they are waterproof. I personally think it's fugly; the other ones are ok.
http://www.rockport.com/rockport/ess...rproof&start=1