I have been doing work on river flooding in Israel. We have the same problem and use the 1% value also. The best way is to map all areas in the 1% zone and not to allow any new building in such areas/ There was a flood around 1960 in St. Paul, the river level rose about 20 feet (article in the local newspaper) The west side was once an airport and is now being considered for development. Be prepared!
Published by Abba Niv, Drainage Engieer at Zafrir Weinstein Engineers PM
I have been doing work on river flooding in Israel. We have the same problem and use the 1% value also. The best way is to map all areas in the 1% zone and not to allow any new building in such areas/
There was a flood around 1960 in St. Paul, the river level rose about 20 feet (article in the local newspaper)
The west side was once an airport and is now being considered for development. Be prepared!