Yes, I agree that part could have perhaps been more obvious but there were problems with entities in that area. The sparks didn't work due to too many entities in the map. I tried to strip out as much as I could but ultimately had to create a balance.

I REALLY wanted sparks coming off the elevator as it fell as well but alas they just wouldn't work there either. However, all the logic is there, including the spark entities so perhaps if Valve update the hard coded limit now that PCs are generally more capable, they will spring in to life in that area! It's mostly down to the dustmote brushes and sparks not liking each other.
I was going also to have Richard mention the electricity when he went over to the lifts to comment them being out of order but getting hold of our voice actor, redoing the face poser work etc I though would be too much work for such little benefit.
I did lower the water to try and convey you could go underneath but again, it wasn't too obvious. There were sparks on the lifts main power box to try and grab the players attention but they seemed to be a little tempremental so some times when compiled they wouldn't show up. :/
So anyway, I agree and sorry about that :P