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 (2015 to 2024) | 78,356 |
| # of Sites |
Current Ambient Lake Sites
Lake Water Quality Summary 2015 to 2024
Summary statistics last calculated 2/10/2025 12:37:08 PM
| Analyte | Units | # Results | Min | 10th Percentile | 25th Percentile | Median | 75th Percentile | 90th Percentile | Max | Max Sample Date | % Non-detection |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ammonia | mg/l | 3,940 | <0 | <1E-05 | <0.0001 | 0.005 | 0.01 | 0.015 | 0.433 | 7/17/2017 | 44.06 |
| Ammonia-nitrogen | mg/l | 3,967 | <0.0006 | <0.0048 | 0.016 | 0.028 | 0.071 | 0.1844 | 2.53 | 5/1/2024 | 18.60 |
| Calcium carbonate | mg/l | 3,940 | 37.54 | 81 | 95.6075 | 122 | 152.25 | 186.885 | 485 | 8/6/2018 | 0.00 |
| Chlorophyll a | ug/l | 3,967 | <0.392 | 3.3 | 7 | 22.07301 | 50.48416 | 93 | 649.8 | 8/9/2022 | 6.83 |
| Depth, Secchi disk depth | m | 3,962 | 0 | 0.3 | 0.42625 | 0.7 | 1.3 | 2.5 | 11.175 | 6/5/2023 | 0.00 |
| Dissolved oxygen (DO) | mg/l | 3,916 | 0 | 5.3 | 6.8 | 8.27 | 9.7 | 11.5 | 26.1 | 5/16/2016 | 0.00 |
| Dissolved oxygen saturation | % | 3,916 | 0 | 62.9 | 79.9925 | 97.2 | 114.0125 | 137.745 | 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 | 3,965 | <0 | <1.2 | <2.6 | 4 | 9 | 15.72 | 169 | 6/15/2015 | 33.06 |
| Kjeldahl nitrogen | mg/l | 3,824 | <0.16 | 0.6 | 0.86 | 1.22 | 1.76 | 2.34 | 8.84 | 6/13/2023 | 5.94 |
| Microcystin | ug/l | 2,934 | Not calculated when non-detections exceed 50% | 126.9 | 10/23/2024 | 57.50 | |||||
| Nitrate + Nitrite | mg/l | 3,824 | Not calculated when non-detections exceed 50% | 22.6 | 7/6/2015 | 50.60 | |||||
| Orthophosphate | mg/l | 3,966 | Not calculated when non-detections exceed 50% | 2 | 8/25/2024 | 67.45 | |||||
| pH | None | 3,900 | 6.45 | 7.8 | 8.06 | 8.3 | 8.59507 | 8.88 | 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 | 3,940 | 79.4 | 217.99 | 263 | 339 | 434.43 | 546.49 | 1230 | 9/14/2020 | 0.00 |
| Temperature, water | deg C | 3,949 | 10.8 | 19 | 21.65455 | 23.9 | 25.93 | 27.4 | 31.7 | 7/11/2017 | 0.00 |
| Total dissolved solids | mg/l | 3,935 | 51.7 | 140 | 170.68333 | 220 | 281.75 | 355 | 800 | 9/14/2020 | 0.00 |
| Total Phosphorus, mixed forms | mg/l | 3,967 | <0.003 | 0.024 | 0.04215 | 0.0736 | 0.13045 | 0.21534 | 1.992 | 9/15/2021 | 3.10 |
| Total suspended solids | mg/l | 3,965 | <0.8 | <3 | 5.5 | 10.8 | 18 | 29 | 413 | 5/31/2022 | 10.97 |
| Turbidity | NTU | 3,766 | <0 | 1 | 3.6 | 8.3 | 16.19125 | 29.28906 | 427 | 8/23/2017 | 5.50 |
| Volatile Suspended Solids | mg/l | 1,254 | <0 | <3.6 | <4 | 4.3 | 7 | 13 | 182 | 5/22/2023 | 43.30 |
Project Codes in this Program
| Code | Description |
|---|
Additional Summary Calculations
| Parameter | Value |
|---|---|
| TSI (ChlA) | 66 |
| TSI (Secchi) | 59 |
| TSI (TP) | 71 |