East Fork Wapsipinicon River IA 01-WPS-409

from the Bremer/Chickasaw county line (N line S3 T93N R12W Bremer Co.) to confluence with unnamed tributary in SW 1/4 S6 T94N R11W Chickasaw Co.

Assessment Cycle

2018

Release Status

Final

Data Collection Period

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.

Overall IR Category: 3 - Insufficient data exist to determine whether any designated uses are met.
Trend: Unknown

Created: 7/22/2019 9:15:10 AM
Updated: 7/22/2019 9:15:10 AM

Assessment conducted in accordance with Iowa's 2018 IR methodology

Use Support

Class A1

Recreation

Primary contact

Not Assessed

Class BWW2

Aquatic Life

Warm Water Type 2

Not Assessed

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” due to lack of information upon which to base an assessment. The Class B(WW2) aquatic life uses remain “not assessed” based on results of fish kill follow-up monitoring conducted by DNR staff in August 2015.

Assessment Explanation

The kill occurred on or before August 20, 2008. The kill killed 76,292 fish along 2.5 miles of the East Fork of the Wapsipinicon River. The value of the fish was estimated to be $40,053.15. No cause for the kill was identified. Water samples were collected at the time of the kill that ruled out livestock manure as the source of the kill.

This stream segment’s fish community was sampled on August 4, 2015, as part of the DNR Watershed Improvement and Water Quality Monitoring & Assessment sections’ fishkill follow up monitoring program. Sampling methods described in DNR’s fish kill follow-up protocol (Attachment 5 of Iowa’s 2016 assessment/listing methodology) were followed. Approximately 700 feet of stream were sampled using a single pass with two backpack electro fishing units. Results of this sampling show that this stream supports approximately 4,250 fish per mile compared to the Level IV ecoregion 47c average of approximately 3,900 fish per mile; 82% of the expected fish taxa for this ecoregion were sampled. The results from this follow-up sampling and comparison of these results to ecoregion averages suggest that the fish community of this stream segment is similar to or better than non-fishkill impacted streams. Although the results of the fishkill follow-up sampling lack the scientific rigor to determine whether the designated aquatic life uses are “fully supported,” the results do indicate that the stream has recovered from the August 2008 fish kill event. Thus, the assessment of aquatic life use support for this stream segment was moved from impairment Category 5b of Iowa’s Integrated Report to Category 3a (designated use not assessed).

Monitoring and Methods

Assessment Key Dates

None listed

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

330

Fish surveys