</font><font color="blue" class="small">( Yet another idea might be to place a short section of culvert in one or two inconspicous locations covered with dirt/gravel even if you had to drop down and climb back up a bit.
One could also perhaps construct a "ford" with rocks and/or concrete to cross the stream in one or more places.)</font>
Depending on where you live, either solution might require a permit from the state agency that regulates waterways, and possibly from FEMA. Adding a culvert or a ford changes the channel conveyance and can increase the back up of water in a flood. You may not be allowed to back up additional water off your property, and may be required to prove that you are not backing up additional water.
If you build a culvert, leave the roadway low so a flood that overtops your culvert will kinda stay in the channel and won't make too much of a mess.
A bridge would have the same requirement as a culvert or ford, but a portable bridge might not, particularly if it lives in your barn.
A call to the State Dept of Tranportation or Office of Water Resources, (It varies from state to state) or your County Engineer should tell you if and what kind of permit is needed.
The engineering required for a stream crossing permit is not trivial. Neither is having the Corpse of Engineers show up with cameras and clipboards.
