Klum Lake IA 01-NEM-66

Assessment Comments

Assessment remains based on surveys by IDNR Wildlife Bureau.

Basis for Assessment

SUMMARY:  Continue to assess (evaluate) support of the Class B(LW) aquatic life uses as "partially supported" due to hydrological modifications (flow alterations) that affect this wetland.   This type of impairment is appropriate for Category 4c of Iowa's Integrated Report (i.e., impairment due to a non-pollutant stressor).   Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this wetland.   This assessment is the same as that developed for previous assessment/listing cycles.  

EXPLANATION:  According to the local DNR Wildlife Biologist, this wetland is not impaired by excess nutrients from agricultural lands.   Impacts from hydrological modification, however, continue.   This wetland lies in a levee and drainage district, and the main drainage ditch is adjacent to the wetland basin.   Deepening of the ditch and increased pumping back in the late 1960's or early 1970's completely altered Klum Lake from a mostly open semi-permanent wetland to a seasonal wetland dominated by thick stands of perennial emergent vegetation.   Water is pumped into the basin in the fall for migratory waterfowl use, but this pumping does not remedy the problem.   The impacts from hydrological modification at this wetland are similar to those at Allen Green Refuge Marsh.   Pumping sufficient water to maintain previous wetland conditions at either wetland is not possible given (1) summer evaporation and transpiration rates, (2) current pumping capabilities, and (3) the cost of such pumping.  

Fish consumption uses remain "not assessed."  In general, Iowa wetlands are not managed for recreational fisheries; thus, fish contaminant monitoring is not typically conducted at these waterbodies.