Here's what the "upper" part of the "lower" section of New Hampshire Fish and Game's New Hampton Station looked like this afternoon. These concrete fish runways have been in existence for almost a century (circa 1920) and are a direct descendant of the original concrete runways Boston rich guy George Dickerman built just down the road, in the 1850s...This is the largest state-run Fish Hatchery in New Hampshire and is only dwarfed by the massive Federal Fish Hatcheries in Milford and Berlin.
http://www.wildnh.com/Inside_FandG/hatcheries_visitor_centers.htm