The scale of the model was 1:100 vertical and 1:2000 horizontal. At this scale, the Appalachian Mountains are raised 20 ft above the Gulf of Mexico, the Rocky Mountains by 50 ft. The larger vertical scale was thought to reduce surface-tension and therefore better simulate turbulence. The model used individually cast 10 ft x 10 ft (approximate) concrete panels, contoured with the land shape and river bed, including tributaries, cliffs, lakes, flood plains, bridges, and levees. Metal plugs or divots in the river bed provided roughness to simulate different types of material, whilst folded metal mesh simulated dense foliage. With each gallon of water representing 1.5 million gallons, an entire day of river flow along the whole system could be simulated in 5 minutes.