Lake Iola is a 206 acre impoundment of the South Branch of the Little Wolf River located in and near the Village of Iola. The impoundment drains a relatively small (16,000 acre) primarily open agricultural and forested watershed in a glacial moraine region. Lake Iola has widespread, nuisance aquatic plant growth which the lake district currently attempts to control with contracted, mechanical macrophyte harvester. Lake Iola nutrient levels are lower than expected for natural lakes in the region and lower than an average for impoundments; event inflows, however, were considerably higher. Water clarity is such that the entire lake bottom receives sunlight during most of the growing season. overall, water quality parameters indicated a mesotrophic to early eutrophic status. Macrophytes were widespread and abundant; milfoils (Myriophyllum spp.), flat-stem pondweed (Potamogeton zosteriformes) and Illinois pondweed (Potamoqeton illinoensis) were most abundant. Milfoils probably include Eurasian Milfoil (Myriophyllum spicatum) , which is an exotic macrophyte known to displace native plant assemblages. Sedimentation in Lake lola was estimated to be relatively high (like many impoundments). Sedimentation has reduced the capacity of the impoundment, increased turbidity and contributed to increased macrophyte growth. Overall, near- and long-term recommendations are designed to protect and enhance the resource through reduction of nutrients and sediment inputs to the system and creation of habitat for wildlife and fishery resources. Recommendations include: - designation of upstream (wildlife) and downstream(recreational access} use zones, - continued water quality monitoring to include the addition of a monitoring site in the south Branch of the Little Wolf River inlet, - continued macrophyte harvest in the downstream areas of the impoundment including identification and selective control of Eurasian Milfoil beds, - encouragement of riparian land management and implementation of Best Management Practices (BMP 1 s) throughout the watershed, - assessment of dredging options after designation of a watershed-wide erosion control plan. - Steps should be taken to prevent spread of exotic species to (and potentially from) Lake Iola.

Review existing data on lake and watershed to define data gaps. Initiate public involvement/information program. Water quality monitoring. Event-related nonpoint source runoff monitoring. Macrophyte survey. Identification of sediment loading and sources of sedimentation. Base map of lake and watershed preparation.

10099443

10099443

10099443

10099443

Review existing data on lake and watershed to define data gaps. Initiate public involvement/information program. Water quality monitoring. Event-related nonpoint source runoff monitoring. Macrophyte survey. Identification of sediment loading and sources of sedimentation. Base map of lake and watershed preparation.