Lake Miami IA 04-LDM-1016
Monroe County S20T73NR17W 5 mi. SE of Lovilia.
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trophic
- Hypereutrophic
- Trend
- Stable
- Created
- 10/27/2025 3:09:48 PM
- Updated
- 11/17/2025 2:44:47 PM
The Class A1 use was assessed (monitored) as “not supported” due to poor water clarity caused by non-algal turbidity (IR 4a), algal turbidity (IR 4a), and violations of the Class A1 standard for pH (IR 5a). The Class BLW use was assessed as “not supported” (IR 4a) due to reduced water transparency related to the presence of common carp populations, sedimentation problems in the lake, and violations of the Class BLW standard for pH (IR 5a). The Class HH (fish consumption) use remains assessed (monitored) as “not supported” (IR 5a) based on the results of fish tissue monitoring and the existence of a one meal per week consumption advisory for mercury in this lake. Note: A TMDL for siltation and nutrients at Lake Miami was prepared by DNR and approved by EPA in 2001. Because the Section 303(d) impairment for pH and mercury in fish tissue was not addressed by the TMDL, this waterbody was placed in IR Category 5a (impaired; TMDL needed) for the current assessment/listing cycle.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2020-2024 22680001 Lake
Miami Max Depth
Iowa DNR 6 FT See Below 1140 Lake
Miami
Class A1 - Indicator Bacteria: No Data 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 22680001 6 15 / 5 7.5 9.5 8.5 4 4 YES MONITORED NOT 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 22680001 6 Chlorophyll a TSI 15 / 5 56 85 65 YES MONITORED NOT 22680001 6 Secchi TSI 15 / 5 47 85 73 YES MONITORED NOT 22680001 6 Total Phosphorus TSI 15 / 5 54 83 74 NA NA NA 22680001 6 Fixed suspended solids 15 / 5 0.7 16 3 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 22680001 6 Dissolved Oxygen 14 / 5 3.3 15.3 8.6 2 NA / NA 4 NO MONITORED FULL 22680001 6 pH 15 / 5 7.5 9.5 8.5 4 NA / NA 4 YES MONITORED NOT 22680001 6 Temperature 15 / 5 20.6 29.8 25.3 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 22680001 6 5 32.5913 85.50% 14.5322 60.86% YES EVALUATED WINOFI 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 22680001 6 Ammonia 15 / 5 0.492 0.11 0.05 0 / 1 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) 1140 fillet 2010 largemouth bass 5 NA 0.394
1140 fillet 2009 largemouth bass 4 NA 0.353
Support Level Not A one meal/week mercury consumption advisory for
largemouth bass exists on this segment. Based on IR Methodology, the Class HH
(fish consumption) use was assessed as “not supported.”