The Iowa Flood Center has some very useful tools on their online tool IFIS (Iowa Flood Information System). Click on the link below to access flood inundation mapping tool. Click on Ottumwa. You will be able to zoom in and out on the map. Move the slider under the Flood Map Controller to view effects of different outflows from Red Rock dam. (Note: use computer. Does not work well on mobile device)
https://ifis.iowafloodcenter.org/ifis/app/?snap_view=fmap