Des Moines River IA 04-LDM-1010
from confluence with Soap Cr. (S35 T71NR12W Wapello Co.) to lowhead dam at Ottumwa in S24 T72N R14W Wapello Co.
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Declining
- Trend Comment
- Another Shovelnose Sturgeon fish kill in 2023.
- Created
- 10/27/2025 3:09:44 PM
- Updated
- 1/26/2026 6:25:22 AM
The Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that exceeded state criteria. The Class BWW1 use was assessed as "not supported" based on a history of fish kills. The Class HH (fish consumption) use remains assessed as "fully supported" based on fish tissue sampling data.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 10900002 Des Moines River DS
of Ottumwa at Cliffland Access Iowa DNR 6 BIO See Below 377 Des Moines River Eldon (REMAP #82) Iowa DNR 6 BIO See Below 1307 Des Moines River Agency (REMAP #326) Iowa DNR 6 FT See Below 1127 Des Moines River Cliffland Access – S
of Ottumwa Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean 2014 Geometric Mean Violates Annual Geometric Mean? # Violations % Violations Significantly > 10% Violations Assessment Type Support Level 10900002 6 22/3 90 96 159 YES 1 / 3 2 / 3 No Evaluated Not Benthic Macroinvertebrates: Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 40a BMIBI BIT BMIBI Pass/Fail 1307 8/11/21 13400.0 40a MS Hess 66 Good 41 Pass 377 8/10/20 13443.1 40a MS Floating Art Sub 76 Excellent 41 Pass Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 40a FIBI BIT FIBI Pass/Fail 1307 8/11/21 13400.0 40a MS NA 36 Fair 33 Pass 377 8/10/20 13443.1 40a MS NA 26 Fair 33 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (2/2) Full
Fish Evaluated Fail (1/2) WINOFI Assessment was evaluated because the
drainage areas of the sites Overall Evaluated Fail WINOFI 3bu used for the assessment were greater than
the calibrated range. Class BWW1 – Fishkill Assessment: The Class BWW1 aquatic life use remains assessed as “not supported” due to 2002,
2006, 2012, and 2023 fish kills. These kills are in a series of kills that have
occurred over the last 25 years that appear to involve primarily shovelnose
sturgeon (Scaphirhynchus platorynchus).
Although the cause(s) of the fish kills remains unknown, low flow conditions,
flow alterations, and very high water temperatures are believed to have
contributed to the kills. Other possible causes include: elevated pH levels caused
ambient levels of ammonia in the river to be toxic to the ammonia-intolerant
shovelnose sturgeon and the kills were caused by a virus specific to shovelnose
sturgeon. The aquatic life use was placed in Category 5b based on the best professional
judgement of the IR and DNR fisheries staff responsible for this region of the
river even though there weren’t multiple fish kills in this segment in the last
five years. DNR believes that: (1) the repeated occurrence of these
kills over the last 25 years from the Ottumwa dam to the Mississippi River, (2)
the large numbers of sturgeon killed (thousands), and (3) the likelihood that
these fish kills could be addressed by a TMDL provide overwhelming evidence
that this impairment should reside in IR Category 5b and on the Impaired Waters
List. Due to uncertainty regarding the recovery of the aquatic life following fish kills,
any existing fish kill 5b impairment will remain in Category 5b until more
recent sampling has shown recovery of the aquatic community, the responsible
party has paid restitution for all the historic fish kills, or a TMDL has been
completed addressing the impairment. Details about the 2002 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/515 Details about the 2006 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/689 Details about the 2012 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/867 Details about the 2023 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/1046
Class BWW1- Continuous DO Monitoring: Site ID Data Source ID # Days Monitoring (2020) DO Criteria Type # 2020 violation / Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level 24 hr 0/6 No 377 6 28 16 hr 0/6 No Evaluated Full Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 1127 fillet 2016 channel catfish 3 38.5 0.07 0.02 0.06 1127 tissue plug 2016 white bass 4 27.2 0.05 Support Level Full
Class A1 - Indicator Bacteria: 2012-2014
Class BWW1 - Biological Sampling:
Fish:
Overall:
Class HH - Fish Tissue Sampling: