Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Hickory Grove Lake IA 03-SSK-950

Story County S24T83NR22W 2.5 mi SW of Colo.

Assessment Cycle
1994
Release Status
Final
Result Period
1990 - 1992
Designations
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 03-SSK-00530-L_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Fish Consumption
Not assessed
Primary Contact Recreation
Threatened
Documentation
Assessment Comments

Assessment is based on results of lake monitoring and surveys by IDNR Fisheries Bureau.

Basis for Assessment

Both fishable and swimmable uses were assessed as  FST for the following reasons:  (1) BPJ of DNR Fisheries; (2) results of monitoring show that average levels of chl-a and TSS are approx equal to overall averages for the 86 SPO impoundments sampled in 1990 and 1992; average levels of total-P and secchi depth, however, were worse than the overall averages with the level of total-P worse than the overall average + 1 SD; (3) lake has a sedimentation rate (3.4 cm/yr) and life expectancy (160 years) typical for an SPO impoundment in Iowa; (4) lake supports rel high amounts of swimming and fishing; lake does not have problems with fishkills.   Lake appears to be threatened by high levels of nutrients in NPS runoff and by turbidity that may interfere with swimmable uses.   Although noting the general good WQ and high rec.  use, DSC (1991) notes that algal blooms cause occassional problems.

Monitoring and Methods
Assessment Key Dates
Methods
340 Primary producer surveys (phytoplankton/periphyton/macrophyton)
120 Surveys of fish and game biologists/other professionals
222 Non-fixed-station monitoring (conventional during key seasons and flows)
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 3
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A