Picayune Creek IA 06-BOY-1911

from mouth (NW1/4 S13 T80N R42W Harrison Co.) to headwaters in S27 T81N R40W Shelby 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: 7/29/2019 9:36:57 AM
Updated: 7/29/2019 9:42:20 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

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 the lack of information upon which to base an assessment. The presumptive Class B(WW1) aquatic life uses of this stream are "not assessed" due to the lack of information upon which to base an assessment. Until the 2018 IR cycle, the presumptive Class B(WW1) aquatic life uses were assessed as “partially supported” due to a fish kill in November 2004. Due to age of the kill, this assessment is moved from IR Category 4d to Category 3b. For this cycle, this assessment was moved to 3a (not assessed) due to the age of the kill and the uncertainty the kill affected this segment.

Assessment Explanation

According to the DNR assessment/listing methodology, 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 is identified, and the cause is either known, or suspected, to be a “pollutant”, the assessment type is considered “monitored” and the affected waterbody is a candidate for Section 303(d) listing. If, however, a consent order has been issued to the party responsible for the kill and monetary restitution has been sought for the fish killed, the affected waterbody will be placed in IR Category 4d (impaired but TMDL not required). Thus, this assessment segment was placed in Category 4d of Iowa’s 2006 Integrated Report.

According to DNR’s assessment/listing methodology, if no additional fish kills have occurred over at least a five-year period, the assessment of impairment should be considered “evaluated” (i.e., of lower confidence), and the waterbody segment should be moved from IR Category 4d to IR Category 3b (list of waters in need of further investigation). Thus, because this kill occurred more than five years ago and no subsequent kills had been reported, this impairment was moved to Category 3b of Iowa's 2012 Integrated Report, and this assessment segment was added to Iowa’s list of waters in need of further investigation.

According to DNR’s assessment/listing methodology, if no additional fish kills have occurred over an additional a five-year period, the assessment should be considered "not assessed", and the waterbody segment should be moved from IR Category 3b to IR Category 3a. Thus, because this kill occurred more than 10 years ago and no subsequent kills had been reported (and the original fish kill is no longer linked to this segment), this impairment was moved to Category 3a of Iowa's 2018 Integrated Report.

Monitoring and Methods

Assessment Key Dates

None listed

Methods

None listed