Hawkeye Wildlife Area IA 02-IOW-632

Johnson County S22T81NR7W 5 mi. NW of North Liberty.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2012 - 2014
Stream/River Water Quality Data	CY 2012 - 2014
Lake Water Quality Data	CY 2010 - 2014
Biological Sampling Data	CY 2010 - 2014*
Fish Kill Data	CY 2010 - 2014
Fish Tissue Sampling Data	CY 2010 - 2014
Continuous Dissolved Oxygen Sampling Data	CY 2010 - 2014
*Biological sites sampled in both 2009 and 2013 were also assessed.

Open Segment Map
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Cycle: 2016
Release Status: Final
Overall IR: 3 - Insufficient data exist to determine whether any designated uses are met.
Trend: Unknown
Created: 8/24/2016 8:53:54 AM
Updated: 8/24/2016 8:53:54 AM

Use Support

Class A1

Recreation - Primary contact

Not Assessed

Class BWW1

Aquatic Life - Warm Water Type 1

WINOFI

Sedimentation/Siltation

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

Continuing

Source

Hydromodification: Bank or Shoreline Modification or Destabilization

Source Confidence

N/A

Cycle Added

2002

Impairment Rationale

Adverse impacts on plant/animal communities

Data Source

Biological monitoring: Iowa DNR Wildlife

Exotic/Invasive Species

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2002

Impairment Rationale

Adverse impacts on plant/animal communities

Data Source

Biological monitoring: Iowa DNR Wildlife

Class HH

Human Health -

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The aquatic life uses remain assessed (evaluated) as "partially supported" due to delivery of silt/sediment to this on-stream wetland area. Primary contact recreation uses and fish consumption uses remain "not assessed" due to lack of information upon which to base an assessment. This is the same assessment as that developed for previous assessment/listing cycles.

Assessment Explanation

The Class B(LW) aquatic life uses remain assessed (evaluated) as "partially supported."  According to the local DNR Wildlife Biologist (Thompson), this wetland area continues to receive sediment.   A report from the U.S.   Army Corps of Engineers, however, states that the rate of sedimentation has been less than originally predicted.   The assessment category for this wetland of "evaluated" indicates that the assessment is based 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 ]) 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.

The primary contact recreation uses remain "not assessed" due to a lack of water quality information upon which to base an assessment.   In general, Iowa wetlands are not managed to support primary contact recreation.

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

None listed

Methods

120

Surveys of fish and game biologists/other professionals