The mid-spillway crane has exited stage right. Just in time for the sidewall section "joining". There is a small hillside "jog" that likely was filled in with support cribbing & wood to facilitate an even weight distribution. You wouldn't want to have a focused weight on the back tracks so as to protect the finishing concrete layer.
Another interesting question arises on the curved sidewall form that is laying in the spillway next to the far sidewall. This may have been an unintentional result from excessive adhesion in removing the sidewall from the concrete pour.
How? The inner wood of the sidewall forms are coated with a material that is intended to facilitate a non-bonding interface to the newly poured concrete. If this interface coating isn't "just right" the pull forces to remove the form may result in what is currently the "bent condition" of this form. The form has a set of seven steel dual "ribs" that are designed to "stiffen" the form. The bent nature of the form reveals the strong forces to cause this curvature of the array of steel ribbings.
The other possibility is that these forms are intentionally slightly curved in construction to facilitate a positive contact force with the internal spacer blocks. Anchoring the form in the concrete with temporary bolts at the bottom and then the steel supports maintain the upper form positive contact force.
When comparing the Sep 18, 2017 post 4262 photo of the crane in the spillway, there are forms stacked that are straight and true that are adjacent to a "curved" form. Thus, contradicting the supposition of a pre-curved construction approach.
Optimal construction requires the "reuse" of these forms. Perhaps they have a way of rehabilitating or readjusting a form back to its reusable state - without a significant amount of work.
Perhaps a time lapse series of the construction would give clues to this puzzle.
How will they Get the Crane Out? (Post# 4262)
Crane exit path revealed. Wood support materials likely used for small hillside climb & to distribute the weight over the leveling concrete. Near picture view reveals root ball has been removed plus rock materials. The original tree with the "cut" remains in this photo.
