Report year: 2025
Waterbody name: Crystal Lake
WBIC: 45200
Station ID: 603120
County: Sheboygan
Lake area: 129 acres
Max. depth: 61 feet
Lake type: SEEPAGE
This report summarizes data routinely collected by the Citizen Lake Monitoring Network.
p. 2-3: Plots summarizing the trophic status and clarity of this lake over time.
p. 4-6: Trends over time in water clarity, total phosphorus, and chlorophyll-a
p. 7+: Tables of observations made during the selected report year, and temperature and dissolved oxygen profiles.
Trophic state indices (TSI) indicate the amount of nutrients in the lake. The TSI equations use late summer (July 15 - September 15) averages of Secchi depth, total phosphorus, and chlorophyll-α.
Secchi disc depth is a measure of water clarity made by measuring the depth at which a black and white disc is just barely visible in the water. The above figure shows average Secchi disc depths calculated from all July and August readings each year. Low values indicate low water clarity, which can be caused by nutrients fueling the growth of algae, by particles suspended in the water, or from dark staining by dissolved tannins (naturally occurring compounds in leaves).
Secchi depth is increasing over time in spring, late summer, early summer, and fall.
Total phosphorus is decreasing over time in spring, late summer, and early summer. Total phosphorus exhibits no trend over time in fall.
Not enough data to calculate trends in spring. Chlorophyll-a is increasing over time in late summer. Chlorophyll-a is decreasing over time in fall and early summer.
| Date | Secchi depth (ft) | Secchi hit bottom | TSI_Secchi | Total phosphorus (mg/L) | TSI_TotalP | Chlorophyll-a (μg/L) | TSI_Chla | Water color | Water clarity | User perception |
|---|---|---|---|---|---|---|---|---|---|---|
| 2025-04-08 | 34.1 | no | 26 | BLUE | CLEAR | 1 | ||||
| 2025-05-24 | 23.0 | no | 32 | GREEN | CLEAR | 1 | ||||
| 2025-06-08 | 32.0 | no | 27 | GREEN | CLEAR | 1 | ||||
| 2025-06-17 | 23.0 | no | 32 | GREEN | CLEAR | 1 | ||||
| 2025-06-24 | 25.0 | no | 31 | GREEN | CLEAR | 2 | ||||
| 2025-06-28 | no | 0.012 | 47 | 1.0 | 35 | |||||
| 2025-07-02 | 20.0 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-07-11 | 17.0 | no | 36 | GREEN | CLEAR | 1 | ||||
| 2025-07-25 | no | 1.1 | 36 | |||||||
| 2025-07-27 | 21.0 | no | 33 | GREEN | CLEAR | 1 | ||||
| 2025-08-03 | 22.0 | no | 33 | GREEN | CLEAR | 1 | ||||
| 2025-08-07 | 18.0 | no | 35 | 1.3 | 37 | GREEN | CLEAR | 1 | ||
| 2025-08-12 | 19.5 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-08-20 | 20.0 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-08-31 | 22.0 | no | 33 | 0.010 | 46 | 1.6 | 38 | GREEN | CLEAR | 1 |
| 2025-09-07 | 21.0 | no | 33 | GREEN | CLEAR | 1 | ||||
| 2025-09-12 | 19.5 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-09-21 | 20.0 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-09-28 | 19.0 | no | 35 | GREEN | CLEAR | 1 | ||||
| 2025-10-07 | 20.5 | no | 34 | GREEN | CLEAR | 1 | ||||
| 2025-10-14 | 19.5 | no | 34 | GREEN | CLEAR | 1 |
| 1 | Beautiful, could not be nicer |
| 2 | Very minor aesthetic problems |
| 3 | Enjoyment somewhat impaired (algae) |
| 4 | Would not swim but boating OK (algae) |
| 5 | Enjoyment substantially impaired (algae) |
The plot on the left shows how temperature changes from the lake surface (at the top of the plot) to the lake bottom on each sampling date. The plot on the right shows how dissolved oxygen changes from the surface to the bottom. Look for seasonal changes. In spring and fall, most lakes will have steady temperatures and oxygen concentrations throughout the water column. In summer, some lakes will warm near the top and remain cool near the bottom. Those lakes may also have low concentrations of oxygen near the lake bottom.
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-10-14 | 0.0 | 62.6 | |
| 2025-10-14 | 5.0 | 62.8 | |
| 2025-10-14 | 10.0 | 63.1 | |
| 2025-10-14 | 15.0 | 63.3 | |
| 2025-10-14 | 20.0 | 63.5 | |
| 2025-10-14 | 25.0 | 64.0 | |
| 2025-10-14 | 30.0 | 64.6 | |
| 2025-10-14 | 35.0 | 62.2 | |
| 2025-10-14 | 40.0 | 55.4 | |
| 2025-10-14 | 45.0 | 53.2 | |
| 2025-10-14 | 50.0 | 51.6 | |
| 2025-10-14 | 55.0 | 53.4 | |
| 2025-10-14 | 60.0 | 51.4 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-10-07 | 0.0 | 70.5 | |
| 2025-10-07 | 5.0 | 71.4 | |
| 2025-10-07 | 10.0 | 71.8 | |
| 2025-10-07 | 15.0 | 72.3 | |
| 2025-10-07 | 20.0 | 73.0 | |
| 2025-10-07 | 25.0 | 72.8 | |
| 2025-10-07 | 30.0 | 70.0 | |
| 2025-10-07 | 35.0 | 66.2 | |
| 2025-10-07 | 40.0 | 60.6 | |
| 2025-10-07 | 45.0 | 57.6 | |
| 2025-10-07 | 50.0 | 55.8 | |
| 2025-10-07 | 55.0 | 53.2 | |
| 2025-10-07 | 60.0 | 51.5 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-09-28 | 0.0 | 71.1 | |
| 2025-09-28 | 5.0 | 68.5 | |
| 2025-09-28 | 10.0 | 68.0 | |
| 2025-09-28 | 15.0 | 68.0 | |
| 2025-09-28 | 20.0 | 67.6 | |
| 2025-09-28 | 25.0 | 66.6 | |
| 2025-09-28 | 30.0 | 65.1 | |
| 2025-09-28 | 35.0 | 62.8 | |
| 2025-09-28 | 40.0 | 58.0 | |
| 2025-09-28 | 45.0 | 51.3 | |
| 2025-09-28 | 50.0 | 49.8 | |
| 2025-09-28 | 55.0 | 48.4 | |
| 2025-09-28 | 60.0 | 48.0 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-09-21 | 0.0 | 73.0 | |
| 2025-09-21 | 5.0 | 73.8 | |
| 2025-09-21 | 10.0 | 73.0 | |
| 2025-09-21 | 15.0 | 72.3 | |
| 2025-09-21 | 20.0 | 70.0 | |
| 2025-09-21 | 25.0 | 68.9 | |
| 2025-09-21 | 30.0 | 66.2 | |
| 2025-09-21 | 35.0 | 62.1 | |
| 2025-09-21 | 40.0 | 56.8 | |
| 2025-09-21 | 45.0 | 54.0 | |
| 2025-09-21 | 50.0 | 53.1 | |
| 2025-09-21 | 55.0 | 51.3 | |
| 2025-09-21 | 60.0 | 49.3 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-09-12 | 0.0 | 79.3 | |
| 2025-09-12 | 5.0 | 81.3 | |
| 2025-09-12 | 10.0 | 79.0 | |
| 2025-09-12 | 15.0 | 77.7 | |
| 2025-09-12 | 20.0 | 77.2 | |
| 2025-09-12 | 25.0 | 76.1 | |
| 2025-09-12 | 30.0 | 73.9 | |
| 2025-09-12 | 35.0 | 66.2 | |
| 2025-09-12 | 40.0 | 60.8 | |
| 2025-09-12 | 45.0 | 57.7 | |
| 2025-09-12 | 50.0 | 55.0 | |
| 2025-09-12 | 55.0 | 53.8 | |
| 2025-09-12 | 60.0 | 52.5 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-09-07 | 0.0 | 73.2 | |
| 2025-09-07 | 5.0 | 74.3 | |
| 2025-09-07 | 10.0 | 74.5 | |
| 2025-09-07 | 15.0 | 74.1 | |
| 2025-09-07 | 20.0 | 70.5 | |
| 2025-09-07 | 25.0 | 70.3 | |
| 2025-09-07 | 30.0 | 65.6 | |
| 2025-09-07 | 35.0 | 61.8 | |
| 2025-09-07 | 40.0 | 56.6 | |
| 2025-09-07 | 45.0 | 53.1 | |
| 2025-09-07 | 50.0 | 53.5 | |
| 2025-09-07 | 55.0 | 51.0 | |
| 2025-09-07 | 60.0 | 49.9 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-08-31 | 0.0 | 71.2 | |
| 2025-08-31 | 5.0 | 70.3 | |
| 2025-08-31 | 10.0 | 70.2 | |
| 2025-08-31 | 15.0 | 70.3 | |
| 2025-08-31 | 20.0 | 70.7 | |
| 2025-08-31 | 25.0 | 69.3 | |
| 2025-08-31 | 30.0 | 62.4 | |
| 2025-08-31 | 35.0 | 55.8 | |
| 2025-08-31 | 40.0 | 51.8 | |
| 2025-08-31 | 45.0 | 49.1 | |
| 2025-08-31 | 50.0 | 47.7 | |
| 2025-08-31 | 55.0 | 46.8 | |
| 2025-08-31 | 60.0 | 46.0 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-08-20 | 0.0 | 76.6 | |
| 2025-08-20 | 5.0 | 76.8 | |
| 2025-08-20 | 10.0 | 77.0 | |
| 2025-08-20 | 15.0 | 77.2 | |
| 2025-08-20 | 20.0 | 77.4 | |
| 2025-08-20 | 25.0 | 69.8 | |
| 2025-08-20 | 30.0 | 64.2 | |
| 2025-08-20 | 35.0 | 59.0 | |
| 2025-08-20 | 40.0 | 55.9 | |
| 2025-08-20 | 45.0 | 53.6 | |
| 2025-08-20 | 50.0 | 51.6 | |
| 2025-08-20 | 55.0 | 50.5 | |
| 2025-08-20 | 60.0 | 49.8 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-08-12 | 0.0 | 79.3 | |
| 2025-08-12 | 5.0 | 79.5 | |
| 2025-08-12 | 10.0 | 79.5 | |
| 2025-08-12 | 15.0 | 79.1 | |
| 2025-08-12 | 20.0 | 75.7 | |
| 2025-08-12 | 25.0 | 68.0 | |
| 2025-08-12 | 30.0 | 62.2 | |
| 2025-08-12 | 35.0 | 57.7 | |
| 2025-08-12 | 40.0 | 54.1 | |
| 2025-08-12 | 45.0 | 51.3 | |
| 2025-08-12 | 50.0 | 50.0 | |
| 2025-08-12 | 55.0 | 49.3 | |
| 2025-08-12 | 60.0 | 48.4 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-08-07 | 3.0 | 79.5 | 9.1 |
| 2025-08-07 | 6.0 | 79.2 | 9.2 |
| 2025-08-07 | 9.0 | 78.8 | 9.4 |
| 2025-08-07 | 12.0 | 78.3 | 9.4 |
| 2025-08-07 | 15.0 | 78.1 | 9.3 |
| 2025-08-07 | 18.0 | 77.7 | 9.3 |
| 2025-08-07 | 21.0 | 72.0 | 10.9 |
| 2025-08-07 | 24.0 | 67.3 | 10.1 |
| 2025-08-07 | 27.0 | 63.0 | 5.3 |
| 2025-08-07 | 30.0 | 59.9 | 3.0 |
| 2025-08-07 | 33.0 | 57.2 | 2.8 |
| 2025-08-07 | 36.0 | 54.1 | 3.5 |
| 2025-08-07 | 39.0 | 52.0 | 2.6 |
| 2025-08-07 | 42.0 | 50.4 | 0.3 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-08-03 | 0.0 | 75.2 | |
| 2025-08-03 | 5.0 | 75.4 | |
| 2025-08-03 | 10.0 | 76.4 | |
| 2025-08-03 | 15.0 | 76.6 | |
| 2025-08-03 | 20.0 | 74.3 | |
| 2025-08-03 | 25.0 | 65.8 | |
| 2025-08-03 | 30.0 | 60.3 | |
| 2025-08-03 | 35.0 | 56.3 | |
| 2025-08-03 | 40.0 | 53.1 | |
| 2025-08-03 | 45.0 | 51.4 | |
| 2025-08-03 | 50.0 | 51.1 | |
| 2025-08-03 | 55.0 | 50.5 | |
| 2025-08-03 | 60.0 | 50.1 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-07-27 | 0.0 | 77.6 | |
| 2025-07-27 | 5.0 | 76.6 | |
| 2025-07-27 | 10.0 | 76.3 | |
| 2025-07-27 | 15.0 | 75.7 | |
| 2025-07-27 | 20.0 | 70.0 | |
| 2025-07-27 | 25.0 | 62.1 | |
| 2025-07-27 | 30.0 | 56.8 | |
| 2025-07-27 | 35.0 | 52.7 | |
| 2025-07-27 | 40.0 | 49.3 | |
| 2025-07-27 | 45.0 | 47.3 | |
| 2025-07-27 | 50.0 | 46.4 | |
| 2025-07-27 | 55.0 | 46.0 | |
| 2025-07-27 | 60.0 | 45.0 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-07-11 | 0.0 | 78.1 | |
| 2025-07-11 | 5.0 | 78.1 | |
| 2025-07-11 | 10.0 | 77.7 | |
| 2025-07-11 | 15.0 | 77.2 | |
| 2025-07-11 | 20.0 | 68.7 | |
| 2025-07-11 | 25.0 | 64.0 | |
| 2025-07-11 | 30.0 | 58.1 | |
| 2025-07-11 | 35.0 | 54.5 | |
| 2025-07-11 | 40.0 | 54.3 | |
| 2025-07-11 | 45.0 | 50.2 | |
| 2025-07-11 | 50.0 | 49.3 | |
| 2025-07-11 | 55.0 | 48.7 | |
| 2025-07-11 | 60.0 | 48.4 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-07-02 | 0.0 | 88.7 | |
| 2025-07-02 | 5.0 | 88.6 | |
| 2025-07-02 | 10.0 | 86.9 | |
| 2025-07-02 | 15.0 | 78.8 | |
| 2025-07-02 | 20.0 | 77.4 | |
| 2025-07-02 | 25.0 | 79.5 | |
| 2025-07-02 | 30.0 | 75.4 | |
| 2025-07-02 | 35.0 | 70.5 | |
| 2025-07-02 | 40.0 | 66.9 | |
| 2025-07-02 | 45.0 | 63.9 | |
| 2025-07-02 | 50.0 | 62.1 | |
| 2025-07-02 | 55.0 | 61.0 | |
| 2025-07-02 | 60.0 | 59.1 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-06-24 | 0.0 | 81.5 | |
| 2025-06-24 | 5.0 | 82.6 | |
| 2025-06-24 | 10.0 | 82.4 | |
| 2025-06-24 | 15.0 | 74.1 | |
| 2025-06-24 | 20.0 | 69.8 | |
| 2025-06-24 | 25.0 | 64.9 | |
| 2025-06-24 | 30.0 | 61.7 | |
| 2025-06-24 | 35.0 | 58.5 | |
| 2025-06-24 | 40.0 | 55.2 | |
| 2025-06-24 | 45.0 | 53.1 | |
| 2025-06-24 | 50.0 | 52.9 | |
| 2025-06-24 | 55.0 | 53.2 | |
| 2025-06-24 | 60.0 | 53.4 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-06-17 | 0.0 | 68.7 | |
| 2025-06-17 | 5.0 | 68.4 | |
| 2025-06-17 | 10.0 | 68.2 | |
| 2025-06-17 | 15.0 | 65.8 | |
| 2025-06-17 | 20.0 | 63.3 | |
| 2025-06-17 | 25.0 | 62.2 | |
| 2025-06-17 | 30.0 | 57.4 | |
| 2025-06-17 | 35.0 | 53.4 | |
| 2025-06-17 | 40.0 | 50.9 | |
| 2025-06-17 | 45.0 | 49.8 | |
| 2025-06-17 | 50.0 | 48.9 | |
| 2025-06-17 | 55.0 | 48.7 | |
| 2025-06-17 | 60.0 | 48.6 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-06-08 | 0.0 | 77.0 | |
| 2025-06-08 | 5.0 | 76.6 | |
| 2025-06-08 | 10.0 | 76.8 | |
| 2025-06-08 | 15.0 | 72.3 | |
| 2025-06-08 | 20.0 | 69.3 | |
| 2025-06-08 | 25.0 | 66.7 | |
| 2025-06-08 | 30.0 | 64.4 | |
| 2025-06-08 | 35.0 | 61.2 | |
| 2025-06-08 | 40.0 | 58.3 | |
| 2025-06-08 | 45.0 | 57.2 | |
| 2025-06-08 | 50.0 | 55.9 | |
| 2025-06-08 | 55.0 | 55.8 | |
| 2025-06-08 | 60.0 | 54.1 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-05-24 | 0.0 | 61.0 | |
| 2025-05-24 | 5.0 | 60.4 | |
| 2025-05-24 | 10.0 | 59.4 | |
| 2025-05-24 | 15.0 | 58.8 | |
| 2025-05-24 | 20.0 | 58.4 | |
| 2025-05-24 | 25.0 | 57.4 | |
| 2025-05-24 | 30.0 | 54.3 | |
| 2025-05-24 | 35.0 | 53.1 | |
| 2025-05-24 | 40.0 | 51.3 | |
| 2025-05-24 | 45.0 | 50.2 | |
| 2025-05-24 | 50.0 | 49.5 | |
| 2025-05-24 | 55.0 | 49.1 | |
| 2025-05-24 | 60.0 | 49.3 |
| Date | Depth (ft) | Temperature (F) | Dissolved oxygen (mg/L) |
|---|---|---|---|
| 2025-04-08 | 3.0 | 42.6 | 12.1 |
| 2025-04-08 | 6.0 | 42.4 | 12.1 |
| 2025-04-08 | 9.0 | 42.3 | 12.1 |
| 2025-04-08 | 12.0 | 42.3 | 12.1 |
| 2025-04-08 | 15.0 | 42.3 | 12.1 |
| 2025-04-08 | 18.0 | 42.3 | 12.1 |
| 2025-04-08 | 21.0 | 42.3 | 12.1 |
| 2025-04-08 | 24.0 | 42.3 | 12.1 |
| 2025-04-08 | 27.0 | 42.3 | 12.1 |
| 2025-04-08 | 30.0 | 42.1 | 12.1 |
| 2025-04-08 | 33.0 | 42.1 | 12.1 |
| 2025-04-08 | 36.0 | 42.1 | 12.1 |
| 2025-04-08 | 39.0 | 42.1 | 12.1 |
| 2025-04-08 | 42.0 | 42.1 | 12.1 |
| 2025-04-08 | 45.0 | 42.1 | 12.1 |
| 2025-04-08 | 48.0 | 42.1 | 12.1 |
| 2025-04-08 | 51.0 | 42.1 | 12.1 |
| 2025-04-08 | 54.0 | 42.1 | 12.1 |
| 2025-04-08 | 57.0 | 42.1 | 12.1 |
| 2025-04-08 | 60.0 | 42.1 | 12.1 |