Wish to convincingly model small, low waterfall on a creek adjacent to small grainmill on our HO sectional layout. The grainmill naturally gets it's water power by the diversion of upstream flow thru sluce to waterwheel, with discharge returning to creek below falls. Will probably do creek by painting bed with the usual dark center/lighter stream edges. I'd then apply several coats of poly varnish for water. Low foliage will overhang water's edge in places. Unsure how to proceed on waterfall itself......Tom P.S. Has anyone ever done a model of a fish ladder? This could fit in opposite waterwheel.