The Muddy Creek sub-watershed, located just west of Morris, has a drainage area 144 square miles. The primary landuse cropland interspersed with some pasture and a few feedlots. Lake Hattie is the only water body that is labeled as impaired. The main steam of Muddy Creek, from Chokio west is channelized, and from Chokio east it is listed as a Class 7 stream (of limited resource value). At this time, no assessments have been made to determine impairments in these waters.
Hattie Lake is shallow and hyper-eutrophic. There are several outlets and inlets to Hattie, many of which are channelized streams or ditches, and there are and an unknown number of drain tile outlets influencing the lake. High phosphate levels, chlorophyll levels, and low Secchi disk readings have been common on Hattie for many years. Agricultural row crops surround the lake, with very few adequate buffers. An increase in buffer zones could reduce the nutrient inputs that impair this lake.