Carman Bay (DNR ID: 27-0133-05)
Sampling Location - GPS Coordinates: Surface Area: 307 acres Max. Depth: 52 ft
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Carman Bay is located in Spring Park. Head east on Minnetonka Blvd, and turn right on Co Rd 101 S. Turn right MN-7 and turn right on Oak St. Oak St. merges into Smithtown Rd and continue onto Manitou Rd/Shadywood Rd. Next turn left at Shoreline Dr. Public boat launch is on the left.
Lake Minnetonka is a class 2B lake protected for aquatic life and recreation. Carman Bay was initially sampled by Three Rivers Park District in 2004. MCWD staff have been monitoring the site on Carman Bay on a bi-weekly basis from the time of ice out (April) to the time of fall mixing (mid-October) since 2006.
See Previous Reports.
Monitoring season started in late April and ended in late October. A YSI multi-probe sonde was used to measure dissolved oxygen (DO), temperature (oC), pH, and specific conductivity (µS/cm) at each meter depth from the water surface to the bottom. Additionally, water samples were collected within the first two meters of the surface with a 2-meter composite sampling tube. Samples one meter below the thermocline and one meter above the bottom were collected with a Van Doran water sampler. Surface samples were analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), total nitrogen (TN), where bottom and thermocline samples were analyzed for TP and SRP. Surface concentrations of chlorophyll-a were also analyzed and measurements of Secchi disc depth were recorded.
| 2009 Summer Water Quality Summary |
| Parameters | Range | Mean | TSI Value | Lake Grade |
| Months | June - Sept. | May - Sept. | ||
| Secchi Depth (m) | 1.8 - 4.1 | 2.9 | 45 | A |
| Surface TP (µg/L) | 13 - 26 | 20.1 | 47 | A |
| Chlorophyll-a (µg/L) | 2 - 15 | 6.3 | 49 | A |
| Overall Score | 47 | A |
The following summary refers to Figure 3.5 (a-d).
- Secchi disk depth increased to 4.8 m by middle of May, and then decreased to 2.9 m by
early June. Secchi disk depth remained around 3.3 m until the middle of August when
water transparency increased to 4.1 m. The rest of the season, secchi disk depth decreased
to 4.1 m to 2.0 m (standard > 1.4 m). - There was a general increase in chlorophyll-a concentrations throughout the season, and
remained below the standard except in late September (standard < 14 μg/L). Concentrations
peaked in early June (6 μg/L), late August (11 μg/L), and late September (15
μg/L). - Surface TP concentrations ranged between 16 μg/L and 21 μg/L from late April to late
July, except in the middle of May when TP concentration increased to 32 μg/L. From
early August to early October, TP concentration increased ranging between 22 μg/L and
31 μg/L (standard < 40 μg/L). Surface SRP concentrations remained below the detection
limit (< 0.005 μg/L) for the entire season. - Bottom TP concentrations ranged between 22 μg/L and 65 μg/L from late April to late
June. Then, TP concentrations increased from 209 μg/L to 978 μg/L from early July to
late September and sharply declined to 30 μg/L in early October. Bottom SRP
concentrations ranged from < 0.005 μg/L to 73 μg/L with the peak occurring in early
August.
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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