Lake Macbride IA 02-IOW-629
Johnson County S29T81NR6W 4 mi. W of Solon.
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trophic
- Eutrophic
- Trend
- Stable
- Created
- 10/27/2025 3:09:32 PM
- Updated
- 11/24/2025 2:23:18 PM
The Class A1 use was assessed (monitored) as “not supported” due to violations of the state's indicator bacteria criteria. The Class BLW use was assessed as “fully supported.”. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data. Note: A TMDL for nutrients and siltation at Lake MacBride was prepared by DNR and approved by EPA in 2005. Additionally, a TMDL for Escherichia coli at Lake MacBride was prepared by DNR and approved by EPA in 2022. Thus, bacteria impairment was placed in Category 4a (impaired; TMDL approved) for the current cycle.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2022-2024 21520001 Lake
Macbride Beach
Iowa DNR 6 WQ CY 2020-2024 22520001 Lake
Macbride (maximum water depth)
Iowa DNR 6 FT See Below 1081 Lake
Macbride WSW
of Solon Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples per Year (2022/ 2023/2024) 2022 Geometric Mean 2023 Geometric Mean 2024 Geometric Mean Violates Annual Geometric Mean? # 2022 SSM violations / SSM Violations needed for impairment # 2023 SSM violations / SSM Violations needed for impairment # 2024 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 21520001 6 15/14/14 14 56 54 NO 1 / 4 4 / 4 4 / 4 YES MONITORED NOT Class A1 - pH 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 22520001 6 15 / 5 7.77 8.78 8.28 0 4 NO MONITORED FULL Class A1 - Lake TSI's Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Median Value Median TSI Violation? Assessment Type Support Level 22520001 6 Chlorophyll a TSI 15 / 5 30 68 63 NO MONITORED FULL 22520001 6 Secchi TSI 15 / 5 29 70 62 NO MONITORED FULL 22520001 6 Total Phosphorus TSI 15 / 5 37 81 59 NA NA NA 22520001 6 Fixed suspended solids 15 / 5 0.7 5.5 2 NA NA NA Class BLW - Binomial Parameters: 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 22520001 6 Dissolved Oxygen 15 / 5 4.1 12.4 7.5 2 NA / NA 4 NO MONITORED FULL 22520001 6 pH 15 / 5 7.77 8.78 8.28 0 NA / NA 4 NO MONITORED FULL 22520001 6 Temperature 15 / 5 18.8 27.4 23.6 0 NA / NA 4 NO MONITORED FULL Class BLW - Lake Planktonic Cyanobacteria: Site ID Data Source ID # Samples Maximum Cyanobacteria Wet Mass Maximum Cyanobacteria % Composition Median Cyanobacteria Wet Mass Median Cyanobacteria % Composition Median Cyanobacteria Concentration = 75th Percentile Assessment Type Support Level 22520001 6 4 14.8062 69.57% 3.4585 36.43% NO EVALUATED NA Class BLW - Toxic Parameters: 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 22520001 6 Ammonia 15 / 5 0.212 0.06 0.03 0 / 0 NO MONITORED FULL
Class HH - Fish
Tissue Sampling: Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 1081 tissue plug 2021 hybrid striped bass 10
0.09
1081 tissue plug 2021 white bass 10
0.103
1081 tissue plug 2020 channel catfish 4 55.7 0.084
Support Level Full