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 2023) | 73,261 |
| # of Sites |
Current Ambient Lake Sites
Lake Water Quality Summary 2014 to 2023
Summary statistics last calculated 8/16/2024 8:31:08 AM
| Analyte | Units | # Results | Min | 10th Percentile | 25th Percentile | Median | 75th Percentile | 90th Percentile | Max | Max Sample Date | % Non-detection |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ammonia | mg/l | 3,884 | <0 | <0 | <0.0001 | 0.003 | 0.01 | 0.015 | 0.433 | 7/17/2017 | 38.62 |
| Ammonia-nitrogen | mg/l | 3,911 | <0.0006 | <0.0048 | 0.014 | 0.026 | 0.071 | 0.1866 | 1.72 | 7/25/2022 | 23.65 |
| Calcium carbonate | mg/l | 3,884 | 37.54 | 81 | 96 | 123 | 154 | 190 | 485 | 8/6/2018 | 0.00 |
| Chlorophyll a | ug/l | 3,911 | <0.4 | 3.3 | 7.04 | 22 | 48.97492 | 88 | 649.8 | 8/9/2022 | 7.70 |
| Depth, Secchi disk depth | m | 3,514 | 0 | 0.3 | 0.45 | 0.7 | 1.3 | 2.5 | 10 | 7/21/2015 | 0.00 |
| Dissolved oxygen (DO) | mg/l | 3,468 | 0.8 | 5.424 | 7 | 8.44 | 10 | 11.9 | 26.1 | 5/16/2016 | 0.00 |
| Dissolved oxygen saturation | % | 3,468 | 9.1 | 64.35975 | 82.34 | 99.31 | 118.3225 | 141.93 | 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 | 3,911 | <0 | <1.2 | <2.1 | 4 | 8 | 15 | 169 | 6/15/2015 | 34.52 |
| Kjeldahl nitrogen | mg/l | 3,768 | <0.16 | 0.57 | 0.86 | 1.19 | 1.71 | 2.333 | 8.84 | 6/13/2023 | 6.08 |
| Microcystin | ug/l | 2,480 | Not calculated when non-detections exceed 50% | 117.9 | 8/21/2017 | 59.80 | |||||
| Nitrate + Nitrite | mg/l | 3,768 | Not calculated when non-detections exceed 50% | 22.6 | 7/6/2015 | 52.15 | |||||
| Orthophosphate | mg/l | 3,910 | Not calculated when non-detections exceed 50% | 1.14 | 9/15/2021 | 69.00 | |||||
| pH | None | 3,452 | 6.7 | 7.8 | 8.1 | 8.33 | 8.6 | 8.9 | 10.1 | 8/1/2017 | 0.00 |
| Phycocyanin | ug/l | 2,693 | <1.8 | <7 | 22.3 | 60.87936 | 126.4 | 220.02 | 11107.53 | 6/28/2022 | 10.10 |
| Specific conductance | uS/cm | 3,492 | 79.4 | 210 | 253.795 | 330.11 | 430 | 537 | 1230 | 9/14/2020 | 0.00 |
| Temperature, water | deg C | 3,501 | 10.34 | 18.61538 | 21.7 | 23.9 | 25.95 | 27.4 | 31.7 | 7/11/2017 | 0.00 |
| Total dissolved solids | mg/l | 3,487 | 51.7 | 136.288 | 165.46286 | 215.3 | 280 | 350 | 800 | 9/14/2020 | 0.00 |
| Total Phosphorus, mixed forms | mg/l | 3,911 | <0.004 | 0.0242 | 0.043 | 0.075 | 0.133 | 0.219 | 1.992 | 9/15/2021 | 3.17 |
| Total suspended solids | mg/l | 3,911 | <0.8 | <3 | 5.6 | 11 | 18 | 29 | 413 | 5/31/2022 | 10.18 |
| Turbidity | NTU | 3,327 | <0 | 1.5 | 4.2 | 9.1 | 17.28938 | 30.2 | 427 | 8/23/2017 | 3.46 |
| Volatile Suspended Solids | mg/l | 1,200 | <0 | <2 | 4.3 | 5 | 9.21 | 14.909 | 182 | 5/22/2023 | 22.50 |
Project Codes in this Program
| Code | Description |
|---|
Additional Summary Calculations
| Parameter | Value |
|---|---|
| TSI (ChlA) | 66 |
| TSI (Secchi) | 59 |
| TSI (TP) | 72 |