This was a project I put together because I have been long tired of the ratty wooden bridge, but the other mods out there always changed something else. Here is what I have done in this mod:

Removed the wooden bridge

Widened the river and sloped the terrain leading into the river

Fixed the retaining wall on the Sanctuary side (because removing the old bridge takes more than just the bridge, it also takes part of the retaining wall

Deepened the river along that bank

Adjusted some of the terrain as you enter Sanctuary (no more dirt showing through the road) **Would have done this for the entire settlement, but some of the cells get glitchy when you mess with them. (Yes, I'm looking at you SanctuaryExt04 and your disappearing house)

Cleaned the debris out of the river and along the bank (tried to leave as much scrapping material as I could along the bank)

That's about it.

SUGGESTED OTHER MODS:

To really make this work, you are going to need a settlement border extender (otherwise you won't be able to build all the way across) I am currently running "All Settlements Extended | XB1" by Neeher, and it's just far enough to complete the bridge.

You might also need something like Place Anywhere.

LOAD ORDER

As for placement, I tried top of order, middle, and end of order. I run Scrap That Settlement for all my uber scrapping needs, and it seems that this needs to be below that in load order. The vines and junk that were hanging off the old bridge kept coming back otherwise.

If you have any questions, please feel free to contact me. Since the comment system here is horrible, the best way to contact me is:
on twitter @draco_invictus or on facebook (facebook.com/thedracoinvictus)

Thanks.

Note: The RR side of the river is slightly higher than the Sanctuary side. It's about half a floor thickness difference.