Shimon Marsh IA 04-RAC-1779

Pocahontas County S9T90NR34W 3 mi SE of Varina.

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 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
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Cycle: 2024
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: 11/1/2023 8:13:46 AM
Updated: 2/2/2024 9:43:53 AM

Use Support

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class HH

Human Health -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class BLW use remains assessed (evaluated) as "fully supported” based on information from the DNR Wildlife Bureau. All other designated uses were “not assessed.” This assessment is the same as previous assessment/listing cycles (not impaired).

Assessment Explanation

Class BLW -

The Class BLW aquatic life use remains assessed (evaluated) as "fully supported” based on information from the DNR Wildlife Bureau. According to local DNR wildlife biologist, water clarity seems good, turbidity isn't much of an issue as long as rough fish populations are low. The watershed delivers most of the inputs to this marsh through a county tile that daylights at the South end.

Class HH - Fish Tissue sampling: No Data

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