Williams Creek IA 01-YEL-6641

Confluence with unnamed tributary (T96N R5W Sec17 Allamakee Co) to headwaters (T96N R6W Sec33 Allamakee County)

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 2018 - 2020
Stream/River Water Quality Data	CY 2018 - 2020
Lake Water Quality Data	CY 2016 - 2020
Biological Sampling Data	CY 2016 - 2020*
Fish Kill Data	CY 2016 - 2020
Fish Tissue Sampling Data	CY 2016 - 2020
Continuous Dissolved Oxygen Sampling Data	CY 2016 - 2020
*Biological sites sampled in both 2015 and 2019 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2022
Release Status: Final
Overall IR: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend: Unknown
Created: 1/6/2022 3:12:18 PM
Updated: 1/12/2022 12:27:52 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

Fully Supported

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class BWW1 use was assessed as "fully supported" based on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau. All other designated uses were "not assessed." Although not designated for the coldwater aquatic life use in the Iowa Surface Water Classification Document, this segment was assessed using DNR's coldwater assessment methodology based on the presence of trout and the natural reproduction of trout.

Assessment Explanation

Presumptive Class A1 - No Data

Presumptive Class BWW1 - Trout Natural Reproduction:

Even though Williams Creek is classified as a presumptive Class BWW1 stream, based on the January 2021 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the presumptive Class BWW1 aquatic life use of Williams Creek was assessed as "fully supported." According to the updated summary, this stream was placed in Category I: streams that exhibit consistent natural reproduction and maintain a wild population of one or more trout species without any stocking.

Monitoring and Methods

Assessment Key Dates

1/1/2021

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

330

Fish surveys