Cedar Lake (DNR ID: 27-0039-00)
Sampling Location - GPS Coordinates: Surface Area: 170 acres Max. Depth : 51 ft
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Go east on Minnetonka Blvd and head North on I-494. Take the exit for I-394 E and then take exit 7 for Penn Ave. Merge onto US 12 Service Rd/ S Wayzata Blvd and continue to follow US 12 Service Rd. Turn left on to the ramp to Theodore Wirth Pkwy. Continue on Cedar Lake Pkwy and take a slight left at Cedar Lake Blvd/Cedar Lake Pkwy towards the lake. Cedar Lake is located in the city of Minneapolis.
Cedar Lake is a class 2B dimictic, glacial kettle lake in the Chain of Lakes. It is protected for aquatic life and recreation and has water quality data going back to 1979. Currently Minneapolis Park and Recreation Board (MPRB) staff monitor the lake on a bi-weekly basis and send MCWD the raw data each fall.
Cedar Lake was named for the red cedar found along its shoreline. In some years during the late summer, the lake may mix and then re-stratify (Lee and Jontz, 1997). Cedar Lake was dredge between 1911 and 1917, and channels between Lake of the Isles and Brownie Lake were created in 1913 and 1917. The canal connecting Cedar Lake to Lake of the Isles caused a six foot drop in the water elevation altering the shape of Cedar Lake. The most noticeable change was the land connection of Louis Island; making it a peninsula on the west side of the lake (MPRB, 2006).
Monitoring season started in early May and ended in late October by MPRB. Hydrolab mini-sonde 5 multi-probe measured dissolved oxygen (DO), temperature (oC), pH, and specific conductivity (µS/cm) at each meter depth from the water surface to the bottom. Surface water samples were a composite of the first two meters below the surface while bottom water samples were collected one meter from the bottom. Additional discrete samples were collected throughout the thermocline mixing zone once stratification developed. Surface sample parameters analyzed are extensive, MCWD is concerned with total phosphorus (TP), total nitrogen (TN), and soluble reactive phosphorus (SRP). Surface concentrations of chlorophyll-a were also analyzed and measurements of Secchi disc depth were recorded. Thermocline and bottom samples were analyzed for TP and SRP.
| 2008 Summer Water Quality Summary |
| Parameters | Range | Mean | TSI Value | Lake Grade |
| Months | June - Sept. | May - Sept. | ||
| Secchi Depth (m) | 1.4 - 2.9 | 2.0 | 50 | C |
| Surface TP (µg/L) | 18 - 29 | 22.3 | 49 | B |
| Chlorophyll-a (µg/L) | 2.5 - 10.7 | 7.7 | 51 | A |
| Overall Score | 50 | B |
The following summary refers to Figure 2.5 (a-d).
- Secchi disk depth ranged between 2.3 m and 2.9 m from late April to June except in early May when secchi disk depth decreased to 1.24 m. Secchi disk depth decreased between 1.4 m and 1.7 m until October (standard > 1.2 m).
- Chlorophyll-a concentrations ranged between 7.4 µg/L and 10.8 µg/L for majority of the season. Chlorophyll-a concentrations decreased below 3.3 µg/L only in late May and late June (standard < 15 µg/L). No data was available in early July.
- Surface TP concentrations were 41 µg/L in late April and for the remainder of the season were below the standard limit (< 40 µg/L). Surface SRP concentrations remained below the detection limit (< 0.005 µg/L) except in early June, late July, and October.
- In general, both bottom TP and SRP concentrations increased throughout the season. Bottom TP peaked at 344 µg/L and bottom SRP peaked at 314 µg/L.
Lake Grades and Historical Monitoring Summaries
When available, previous reports are linked to applicable year. Additional lake data previous to 2007 may be available in the applicable year's hydrodata report. If you have additional questions or you are looking for specific information please contact MCWD's Water Quality Staff.
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