Yellow River IA 01-YEL-436
from old Hwy 51 crossing (NE 1/4 S11 T96N R6W Allamakee Co.) to confluence with N. Fk. Yellow R. in S13 T96N R7W Winneshiek Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 6/23/2020 9:23:54 AM
- Updated
- 10/16/2020 6:58:00 AM
The presumptive Class A1 and Class A2 uses remain assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BCW1 use remains assessed as "partially supported" based on a fish kill investigation. All other designated uses were "not assessed". Note: A TMDL for the bacteria impairment for Yellow River basin streams was approved by U.S. EPA in 2013. Due to TMDL completion, the Integrated Report categories for the Class A1 and Class A2 recreational uses were changed from 5p to 4a.
Sources
of Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY2009 11030001 Yellow River Mainstem 1 Iowa DNR 6 BIO See Below 160 Yellow River W60 Bridge – Site 4 Iowa DNR 6 BIO See Below 837 Yellow River Postville (Upstream of HWY 51) Presumptive
Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2009 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 11030001 6 13 / 1 13288 Yes 13 100% Yes Evaluated Not Presumptive
Class A2 - Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2009 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 11030001 6 13 / 1 13288 Yes 9 69% Yes Evaluated Not Class
BCW1 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear CBI score CBI Class CBI BIT CBI Pass/ Fail 160 9/6/12 58 52b MS/CW Hess 49 NA 60 Fail 160 7/24/12 58 52b MS/CW Hess 59.4 NA 60 Pass 837 8/17/11 41 52b MS/CW Hess 60 NA 60 Pass Overall
Assessment: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic Macroinvertebrates Evaluated Pass (2/3) Full 1 1 Assessment
is evaluated because the samples included in the assessment weren’t collected
in the last five years. DNR
normally requires a segment to have a simple majority of passing scores from
multiple years in a five-year period to be considered fully supporting
(monitored). However, this assessment of this segment of the Yellow River
includes the professional judgment of DNR staff incorporating an in-depth
analysis of the metric scores, sampling conditions and the fish sampling that
occurred at the time the benthic macroinvertebrates were sampled. A fish
sample from 2012 contained over 5000 fish per mile and included 337 Brown
Trout of various sizes and one Rainbow Trout. Class
BCW1 – Fishkill Assessment: The Class BCW1 use assessment based on the 2000 fish kill
placed this segment in Category 5b. The fish kill was caused by a “pollutant”
or was suspected to be caused by a “pollutant”; therefore, the Class BCW1 use
was considered impaired. Because the source of the pollutant was not identified
and/or the enforcement actions taken against the responsible party have not
been resolved, the Class BCW1 use was placed in Category 5b. Due to uncertainty
regarding the recovery of the aquatic life following the fish kill, any
existing fish kill 5b impairment will remain in Category 5b until more recent
sampling has shown recovery of the aquatic community or the responsible party
has paid restitution. Details about the 2000 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/462 Class HH – No Data