North Branch Lizard Creek IA 04-UDM-1288

mouth (S2 T91N R31W Pocahontas Co.) to confluence with Drainage Ditch No. 169 in S6 T91N R31W Pocahontas Co.

Assessment Cycle

2020

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 2016 - 2018
Stream/River Water Quality Data	CY 2016 - 2018
Lake Water Quality Data	CY 2014 - 2018
Biological Sampling Data	CY 2014 - 2018*
Fish Kill Data	CY 2014 - 2018
Fish Tissue Sampling Data	CY 2014 - 2018
Continuous Dissolved Oxygen Sampling Data	CY 2014 - 2018
*Biological sites sampled in both 2013 and 2017 were also assessed.

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

Created: 10/7/2020 11:02:06 AM
Updated: 10/13/2020 10:03:34 AM

Assessment conducted in accordance with Iowa's 2020 IR methodology

Use Support

Class A1

Recreation

Primary contact

Presumptive Use

Not Assessed

Class BWW2

Aquatic Life

Warm Water Type 2

WINOFI

Further Investigation Needed

Support Level

Water in Need of Further Investigation (WINOFI)

Impairment Code

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

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

1996

Impairment Rationale

Potential Impairment

Data Source

Special project/study: Iowa DNR

General Use

General Use water

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class BWW2 use remains assessed as "partially supported" based historical biological sampling data and habitat assessment. All other designated uses were "not assessed".

Assessment Explanation

Presumptive Class A1 - No Data

Class BWW2 - Biological Sampling:

The aquatic life use was assessed as "partially supported" due to (1) presence of a relatively depauperate fish community (7 species from 2 families) for streams in the Des Moines Lobe sub-ecoregion (47b) and (2) presence of less than a majority of the expected fish taxa (4 of 11) for streams in the 47b sub-ecoregion, and (3) indications on the field sheet of extensive channel alterations due to channelization and generally poor quality aquatic habitats. Follow-up monitoring is recommended to determine the status of the aquatic communities and habitats of this stream and to determine the degree to which the aquatic life use may be impaired.

Monitoring and Methods

Assessment Key Dates

9/1/1994

DNR Stream Use Assessment

Methods

150

Monitoring data more than 5 years old

330

Fish surveys