Never boring, extremely interesting to read about your adventures. I assume the gradient is in 'metres', so if I walk(or run, due to a slippage chasing me, lol) 30m I would have risen 3m, that's an impressive slope. The history of the road construction is interesting.
It's great to read that you are taking a natural solution to brace the land with vegetation and are using strategic planting. A co-ordinated effort between the contractors would help, as much as their efforts seem impressive the solution does seem to lay with diverting the rainfall in an effective manner.
It's a shame some neighbours aren't taking their role seriously. You mentioned before that the goat neighbour has been removing trees. Actions like this can compound the problem and bring dire consequences to the area, and peoples' lives. Besides bracing the soil a tree can have an effect on rainfall distribution- a canopy can disperse water as a 'shower head) affect as opposed to a direct deluge falling in a concentrated area, akin to watering your garden with a spray nozzle or direct open hose, having less impact on your garden washing away.
As for uploading photos. I copy the original because you need to edit it to resize it for HC and you don't want to end up with your original altered. I copy it to the desktop. From there, right click and edit it to resize it, when you close the image it asks if you want to save it, this is then the new image on your desktop. Then do your HC post, upload photo>browse and choose it from your desktop, open it and details will appear in the bar box, then upload it. If successful it will confirm it in green. The image details will appear at the base of your post. Preview it and the photos will appear.
