Cottonwood River begins as two separate rivers in western Marion County. Both feed Marion Reservoir and are controlled there
Cottonwood River drains much of Marion, Chase and Lyon Counties on the way to join the Neosho River near Emporia and then on to the Arkansas River and ultimately the Mississippi.
Cottonwood River At Emporia
Critical Flood Levels:
29.2 Water reaches the deck of the Old Highway K 99 bridge over the Cottonwood River.
26.5 Water reaches low steel or Old K 99 bridge across the Cottonwood River. 25.5 Highway K 99 on the north bank begins to flood. 24 Highway K 99 on the south bank floods.  23 North bank of the Cottonwood River begins flood. Lowland flooding occurs along the Cottonwood River from Plymouth to Neosho Rapids
20 South Bank of the Cottonwood River 1