Ambient Lake Monitoring
The Ambient Lake Monitoring program samples lakes in Iowa over the summer recreational season. Each lake is sampled three times between May and September: once in early summer, once in mid-summer, and once in late summer/early fall. Data from this project are used to assess the health of our lakes and target individual lakes for restoration and watershed improvement activities. Monitoring is currently completed through a partnership with the Iowa State University Limnology Laboratory.
Program Details
| Sampling Results (2014 to 2024) | 85,975 |
| # of Sites |
Current Ambient Lake Sites
Lake Water Quality Summary 2014 to 2024
Summary statistics last calculated 12/19/2024 4:17:34 PM
| Analyte | Units | # Results | Min | 10th Percentile | 25th Percentile | Median | 75th Percentile | 90th Percentile | Max | Max Sample Date | % Non-detection |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ammonia | mg/l | 4,341 | <0 | <0 | <0.0001 | 0.004 | 0.01 | 0.015 | 0.433 | 7/17/2017 | 43.24 |
| Ammonia-nitrogen | mg/l | 4,368 | <0.0006 | <0.006 | 0.014 | 0.028 | 0.073 | 0.191 | 2.53 | 5/1/2024 | 21.22 |
| Calcium carbonate | mg/l | 4,341 | 37.54 | 81 | 95.9 | 122 | 153 | 187 | 485 | 8/6/2018 | 0.00 |
| Chlorophyll a | ug/l | 4,368 | <0.392 | 3.3 | 7.49841 | 23 | 51 | 92 | 649.8 | 8/9/2022 | 6.89 |
| Depth, Secchi disk depth | m | 4,363 | 0 | 0.3 | 0.45 | 0.7 | 1.3 | 2.5 | 11.175 | 6/5/2023 | 0.00 |
| Dissolved oxygen (DO) | mg/l | 4,317 | 0 | 5.3 | 6.8 | 8.3 | 9.8 | 11.7 | 26.1 | 5/16/2016 | 0.00 |
| Dissolved oxygen saturation | % | 4,317 | 0 | 63 | 80.44 | 97.97 | 115.7 | 138.94 | 310.1 | 9/8/2016 | 0.00 |
| Escherichia coli | MPN/100ml | 410 | <1 | <1 | <1 | 10 | 10 | 20 | 6130 | 5/27/2020 | 47.56 |
| Fixed suspended solids | mg/l | 4,366 | <0 | <1.2 | <2.3075 | 4 | 8.4 | 15 | 169 | 6/15/2015 | 33.46 |
| Kjeldahl nitrogen | mg/l | 4,225 | <0.16 | 0.59898 | 0.86 | 1.23 | 1.77 | 2.38 | 8.84 | 6/13/2023 | 5.44 |
| Microcystin | ug/l | 2,934 | Not calculated when non-detections exceed 50% | 126.9 | 10/23/2024 | 57.50 | |||||
| Nitrate + Nitrite | mg/l | 4,225 | Not calculated when non-detections exceed 50% | 22.6 | 7/6/2015 | 51.41 | |||||
| Orthophosphate | mg/l | 4,367 | Not calculated when non-detections exceed 50% | 2 | 8/25/2024 | 66.68 | |||||
| pH | None | 4,301 | 6.45 | 7.8 | 8.07255 | 8.3 | 8.6 | 8.9 | 10.13 | 5/22/2023 | 0.00 |
| Phycocyanin | ug/l | 3,149 | <1.8 | 7 | 28.6 | 70.6 | 128.65 | 212.02 | 11107.53 | 6/28/2022 | 8.64 |
| Specific conductance | uS/cm | 4,341 | 79.4 | 217 | 260.76667 | 339.3 | 436.5 | 543 | 1230 | 9/14/2020 | 0.00 |
| Temperature, water | deg C | 4,350 | 10.34 | 18.9 | 21.6425 | 23.8 | 25.8 | 27.3 | 31.7 | 7/11/2017 | 0.00 |
| Total dissolved solids | mg/l | 4,336 | 51.7 | 140 | 170 | 220 | 281.025 | 352.75 | 800 | 9/14/2020 | 0.00 |
| Total Phosphorus, mixed forms | mg/l | 4,368 | <0.003 | 0.0244 | 0.043 | 0.07495 | 0.132 | 0.21893 | 1.992 | 9/15/2021 | 2.84 |
| Total suspended solids | mg/l | 4,366 | <0.8 | <3 | 5.5 | 10.8 | 18 | 29 | 413 | 5/31/2022 | 10.54 |
| Turbidity | NTU | 4,167 | <0 | 1.1 | 3.62643 | 8.4 | 16.3 | 29.28688 | 427 | 8/23/2017 | 4.97 |
| Volatile Suspended Solids | mg/l | 1,655 | <0 | <2.6 | <4 | 4.3 | 8.27 | 14.06 | 182 | 5/22/2023 | 32.81 |
Project Codes in this Program
| Code | Description |
|---|
Additional Summary Calculations
| Parameter | Value |
|---|---|
| TSI (ChlA) | 66 |
| TSI (Secchi) | 59 |
| TSI (TP) | 71 |