Jennings Bay (DNR ID: 27-0133-15)
Sampling Location GPS Coordinates: Surface Area: 290 acres Max. Depth: 26 ft
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Jennings Bay is located near the city of Mound. Head east on Minnetonka Blvd and turn left on Co Rd 101 S. Turn right at Grays Bay Blvd and continue on Bushaway Rd. Turn left on Eastman Ln/Shady Ln, then a slight right at E Circle Dr. Take a slight left at Lake St. E. Turn left at Ferndale Rd S and continue on Shoreline Dr. Turn right at Northshore Dr. North Arm public boat access is located off of Northshore Drive two miles west from Shoreline Drive.
Jennings Bay is on Lake Minnetonka which is a class 2B lake protected for aquatic life and recreation. Water quality information is available beginning in 1996. MCWD staff have been monitoring the site on Jennings 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 above the bottom were collected with a Van Doran water sampler. Surface sample were analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), total nitrogen (TN), where the bottom 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) | 0.4 - 1.6 | 0.7 | 64 | C |
| Surface TP (µg/L) | 50 - 143 | 108.0 | 72 | D |
| Chlorophyll-a (µg/L) | 17 - 103 | 53.4 | 70 | C |
| Overall Score | 69 | C- |
The following summary refers to Figure 3.21 (a-d).
- Secchi disk depth increased from 1.1 m to 5.3 m by early May. From late May to late
August, secchi disk depth declined to 0.4 m, and then increased to 0.9 m by early October
(standard > 1.4 m). - Chlorophyll-a concentrations decreased from 12 μg/L to 2 μg/L from late April to early
May, then increased to 62 μg/L in late June. Concentrations peaked again at 103 μg/L in
the middle of August, and then there was an overall decline for the rest of the season
(standard < 14 μg/L). - Surface TP concentrations decreased from 107 μg/L to 50μg/L by early June. TP
concentrations gradually increased over the remainder of the season with concentrations
ranging between 87 μg/L 143 μg/L (standard < 40 μg/L). Surface SRP concentrations
fluctuated throughout the season ranging between less than 0.005 μg/L and 21 μg/L with
the highest concentration occurring in early May (43 μg/L). - Both bottom TP and SRP concentrations declined from late April to late May, and then
peaked in the middle of July (TP = 349 μg/L; SRP= 270 μg/L). The rest of the season
there was an overall decline with both TP and SRP concentrations.
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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