The one inch high water bulkheads plumbed out the back down to a 1.5 inch drain manifold with access at each corner tub. One will tie into the 2 inch line I have down both property limes that can go to the ducks, food culture vessels and to the sewer manhole cover in the back corner. This allows me to move water from any source to any destination via gravity or pump flow.
The drain manifolds are capped so the full tub fills the others through their bulkheads.
I love water.
Eye candy. I can stare at this for hours.