Posted 11/28/2021 09:28 (#9346632 - in reply to #9340610) Subject: RE: Any bridge builders out there?
East Central Illinois. -39.346676, -87.653484
Step 1 is understanding, and then maintaining hydraulic capacity of the channel.
Then determine soil bearing capacity.
Necessary span length will then determine your material/methodology.
If you are transporting people over it you will need the services of (at least) a Professional Engineer (structural &/or civil)