This program places a valve in every other channel of the floctank. This code is the same for horizontal and vertical flocculators.
1) A new layer, "flocdrainvalves," is created.
2) The valves are iteratively inserted as a block in each channel from the channel closest to the sedimentation tank to the channel closest to the entrance tank. The center of the valve is placed at grade.
3) The "flocdrainvalves" layer is frozen.