[Spoiler]

It's neither a creek nor a fake river. It's a recreation of a previously existing acequia. The plan shows trees in the plaza, near the acequia.

I think the purpose of the glass walls is to control people's movement. This is especially true along Houston, where they don't even have the excuse of recreating a former wall.

I like the idea of lowering the ground level to its original level, but the dirt will cause problems. Maybe some type of permeable paver?

I'm less concerned about the loss of trees in the plaza. The plan includes lots of new shady spots along Alamo and Crockett streets. Also, the garden behind the Alamo will become a city park (iirc) and the walls around it will be torn down.