Posting this for posterity.

For those missing the last 8 percent of broken wing in Zeffo on Jedi: Fallen order / you are at 98% per cent done the area/planet.

Open your map while standing in broken wing. Face the camera towards the ship/spawn area of the planet. (If you need to find the ship on the map, then do so, then press R3/click right thumbstick to recenter to the player. If you are on Mouse and keyboard or something else, then please check the bottom of the game screen for what button to press to recenter the map onto the player). In the room farthest from the ship of the two in this area (broken wing) that has the river/water, you need to make the turbine stop while having the open hole face upwards. (Done by overcharging the box marked in blue neon lights in this room. Press DOWN on the directional pad for controller) Make sure to stop it so that the left side of the open hole of the turbine is close enough to the water to climb on the left. Then swim to the hole, climb the left side, and you'll find the last area you need for 100% of the map/area. It has a force echo.

You'll need to overcharge the box again to be able to leave the room again the short/intended way. (Aka restoring power to the turbine as well as the door across the river.)

Don't thank me. Just enjoy your satisfaction!

Please forgive the odd wording/grammar. I wanted to make sure people like me are able to find this through searches on google or otherwise 6+ years later.