After some looking around on this map, I have come up with some major points, good and bad, that I think help embody this map. Good points will be Green, Bad points will be red. Note that I do not have any definite testing notices.
The map is visually pleasing in thematics
You pull off a hydro theme very nicely. Your buildings and displacements capture a nice look of the hydro style. I can pretty much tell that a good bit of the displacement work is not done (like the inside of the caves, that is clearly you just clicking subdivide for those columnar objects), but the general feel is very nice.
The map has plenty of skill jumps as far as I could tell
Skill jumps are a trait I enjoy there being in a map. Most maps have some jumps that just require some skill to do, which adds in dynamicism to the gameplay and makes it more fun for longer.
The map overall looks too precarious to explosive damage
Normally I'm thinking "Sweet! I love pushing people into deathpits", as that is the pyro in me and nothing makes me feel better than seeing a scout fall to his death. On the other hand, there seem to be way too many opportunities for this. The final area is fine (aside from maybe adding railings to the outside of your final passages, I feel), but the staging area into the base could use some lightening up on it, or perhaps you can implement in this next one.
There are areas you can land in that force you to commit suicide.
This is a BIG no. If I fall into a pit and it doesn't kill me, there better be a way out of that damn pit. This is the staging area into the base, there are small ledges there that you can fall on. On the other side of the pipes. I suggest you add some method, even if it is one thin pathway, out of that ledge system. It would help ease potential frustration.
Bases lack large ease of differentiation
Basically, only small details and lighting changes tell me if I'm in blue's base or red's. Personally, this isn't a problem for me, but there are many people out there who can't find a door right in front of their face. Add some more obvious indicators, like the red or blue stripes in gorge on the main buildings and the dam.
The map doesn't do a great job of guiding
When I go out of spawn, I want to go to the fight generally. After one time, I can do that by myself easily. The first time I went out of the spawn, natural progression led me to turn left. Its a small issue in the end, but it could become an issue.
The map itself is of good quality overall
Not much more to say other than that. It felt like a good map when I ran through it. It didn't feel like Valve would have made it, but it wasn't that far away. You're a good mapper and maps like this show some of your skillsets. I like your overall usage of geometry and the general simplicity of it. The map also has a public charm to it, and I believe it could work out well there.