Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Walnut Creek Marsh IA 05-GRA-1384

Ringgold County S17T68NR30W 4 mi WSW of Mount Ayr.

Assessment Cycle
2010
Result Period
2006 - 2008
Designations
Class B(LW) Class HH
Assessment Methodology
Assessment Type
Evaluated
Integrated Report
Category 3b
Legacy ADBCode
IA 05-GRA-01950-L_0
Overall Use Support
Partial
Aquatic Life Use Support
Partial
Fish Consumption
Not assessed
Documentation
Assessment Comments

Assessment remains based on information from the IDNR Wildlife Bureau.

Basis for Assessment

SUMMARY:  The Class B(LW) aquatic life uses remain assessed (evaluated) as "partially supported" based on information from the IDNR Wildlife Bureau.   Fish consumption uses remain "not assessed."  This is the same assessment as that developed for previous assessment/listing cycles.  

EXPLANATION:  The Class B(LW) aquatic life uses remain assessed (evaluated) as "partially supported" based on information from the Iowa DNR Wildlife Bureau.   The assessment category for this wetland of "evaluated" indicates that the assessment is based entirely on "best professional judgment."  In terms of Section 305(b) reporting, "monitored assessments" are based primarily on recent, site-specific ambient monitoring data and thus have relatively high confidence.   IDNR considers waterbodies identified as "impaired" based on "monitored assessments" as candidates for the state's Section 303(d) list.   "Evaluated assessments" are those based on data older than five years or other than site-specific ambient monitoring data (e.g., questionnaire surveys of fish and game biologists [=best professional judgment]) and thus have relatively lower confidence.   IDNR does not consider waterbodies identified as "impaired" based on "evaluated assessments" as candidates for the state's Section 303(d) list.  

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.

Monitoring and Methods
Assessment Key Dates
Methods
120 Surveys of fish and game biologists/other professionals
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 0
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Nutrients Aquatic Life Support Moderate
  • Agriculture
  • Natural Sources
  • Moderate
  • Slight
Siltation Aquatic Life Support Moderate
  • Agriculture
  • Natural Sources
  • Moderate
  • Slight
Exotic species Aquatic Life Support Not Impairing
  • Source Unknown
  • Not Impairing