Beaver Creek IA 04-UDM-1233
mouth (S17 T79N R24W Polk Co.) to the Polk/Dallas county line (west line S18 T80N R25W Polk Co.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 11/1/2023 8:12:59 AM
- Updated
- 1/31/2024 11:15:40 AM
Assessment Summary
The presumptive Class A1 use was assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW2 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data.
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2020-2022 10770001 Beaver
Creek near Grimes
Iowa DNR 6 BIO See Below 910 Beaver
Creek Ambient
Monthly Site Iowa DNR 6 BIO See Below 1336 Beaver
Creek Grimes Site ID Data Source ID # Samples per Year (2020/ 2021/2022) 2020 Geometric Mean 2021 Geometric Mean 2022 Geometric Mean Violates Annual Geometric Mean? # 2020 SSM violations / SSM Violations needed for impairment # 2021 SSM violations / SSM Violations needed for impairment # 2022 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 10770001 6 8/8/8 592 381 791 YES 6 / 3 6 / 3 7 / 3 YES Mon Not Site ID Data Source ID # Samples / # Years Minimum Value Maximum Value Mean Value # Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10770001 6 36 / 3 7.3 8.7 8.2 0 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value # Violations # Acute / Chronic Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10770001 6 Chloride 36 / 3 23 130 57 NA 0 / 0 7 NO Mon Full 10770001 6 Dissolved Oxygen 36 / 3 7 17.2 11.1 0 NA / NA 7 NO Mon Full 10770001 6 pH 36 / 3 7.3 8.7 8.2 0 NA / NA 7 NO Mon Full 10770001 6 Sulfate 36 / 3 18 480 108 0 NA / NA 7 NO Mon Full 10770001 6 Temperature 36 / 3 0 28.1 13.3 0 NA / NA 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 10770001 6 Ammonia 36 / 3 2.2 0.3 0.04 0 / 1 NO Mon Full 10770001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10770001 6 Chromium 20 / 3 2 0.75 0.68 0 / 0 NO Mon Full 10770001 6 Lead 20 / 3 1 0.91 1 0 / 0 NO Mon Full 10770001 6 Nickel 20 / 3 4.5 2.1 2 0 / 0 NO Mon Full 10770001 6 Selenium 18 / 2 3 1.5 1.5 0 / 0 NO Mon Full 10770001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10770001 6 Zinc 20 / 3 7.9 2.1 1.6 0 / 0 NO Mon Full BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/Fail 1336 9/15/22 348.0 47b MS/WW ArtSub 39 Fair 62 Fail 910 7/17/19 358.0 47b MS/WW Floating ArtSub 72 Good 62 Pass 910 8/31/16 358.0 47b MS/WW Floating ArtSub 67 Good 62 Pass BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal Riffle Stream? FIBI score FIBI Class 47b FIBI BIT FIBI Pass/Fail 1336 9/15/22 348.0 47b MS/WW No 45 Fair 32 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic Macroinvertebrates Evaluated Pass (2/3) Full Fish Evaluated Pass (1/1) Full Assessment was evaluated because a BMIBI sample used for the Overall Evaluated Pass Full 1 the assessment was not collected in a recent five-year period.
Presumptive Class A1 - Indicator Bacteria:
PresumptiveClass A1 – pH:
Class BWW2 - Binomial Parameters:
Class BWW2 - Toxic Parameters:
Class BWW2 -
Biological Sampling:
Benthic Macroinvertebrates:
Fish:
Overall:
Assessment Key Dates
1/7/2020 | Monitoring Start |
12/5/2022 | Monitoring End |
7/17/2019 | Biological Monitoring |
8/31/2016 | Biological Monitoring |
9/15/2022 | Biological Monitoring |
Methods
150 | Monitoring data more than 5 years old |
200 | Physical/Chemical Monitoring |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |