Little Wapsipinicon River IA 01-WPS-421

from confluence with Elk Cr. (S1 T96N R14W Chickasaw Co.) to outlet of Lylahs Marsh in S23 T98N R14W Howard Co.

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 2014 - 2016
Stream/River Water Quality Data	CY 2014 - 2016
Lake Water Quality Data	CY 2012 - 2016
Biological Sampling Data	CY 2012 - 2016*
Fish Kill Data	CY 2012 - 2016
Fish Tissue Sampling Data	CY 2012 - 2016
Continuous Dissolved Oxygen Sampling Data	CY 2012 - 2016
*Biological sites sampled in both 2011 and 2015 were also assessed.

Open Segment Map
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Cycle: 2018
Release Status: Final
Overall IR: 3 - Insufficient data exist to determine whether any designated uses are met.
Trend: Unknown
Created: 8/1/2019 2:12:14 PM
Updated: 8/1/2019 2:12:23 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

WINOFI

Fish Kill: Due To Unknown Toxicity

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 (primary contact recreation) uses remain "not assessed" (IR 3a) due to the lack of information upon which to base an assessment. The Class B(WW2) (aquatic life) uses remain assessed (evaluated) as "partially supported" (IR 3b) due to a fish kill. The assessment is based on results of a fish kill investigation on August 8, 2006.

Assessment Explanation

The Class B(WW2) (aquatic life) uses remain assessed (evaluated) as "partially supported" due to a fish kill. The kill occurred on or before August 8, 2006; no cause was attributed to the kill. The kill affected approximately 2.3 miles of the Little Wapsipinicon River south of Elma. The number of fish killed was estimated to be 7,093 fish. The value of the fish was estimated to be $6,190.87. The cost of the fish kill investigation was $243.97.

This is the same assessment as that developed for previous assessment/listing cycles. The continuance of the IR Category 3b listing is based on DNR's 2010 assessment methodology that states the following: the occurrence of a single pollutant-caused fish kill, or a fish kill of unknown origin, on a waterbody or waterbody reach during the most recent assessment period indicates a severe stress to the aquatic community and suggests that the aquatic life uses should be assessed as “impaired”. If a cause of the kill was not identified during the DNR investigation, or if the kill was attributed to non-pollutant causes (e.g., winterkill), the assessment type will be considered “evaluated” and will be placed in IR subcategories 2b or 3b and will be added to the state list of waters in need of further investigation. Thus, this assessment segment will remain in Category 3b of Iowa’s Integrated Report.

Monitoring and Methods

Assessment Key Dates

8/8/2006

Fish Kill

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills