There is one primary stream within the subwatershed: Long Lake Creek, which serves as the outlet of Long Lake and flows to Tanager Lake, which then discharges to Browns Bay of Lake Minnetonka. Part of the creek was channelized as County Ditch #27 (see Figure 2) in 1915 and is discussed in more detail in the following section. Long Lake Creek is included in the District’s Annual Hydrologic Data monitoring program, and was also studied in-depth in 2004 as part of the District’s Upper Watershed Stream Assessment. Flow in the creek is controlled by an outlet weir on Long Lake. Six storm sewer outfalls discharge into the creek. The creek flows through two large wetlands prior to discharging to Tanager Lake. The Stream Assessment identified 16 localized erosion sites and fourteen sites with debris in the channel. Many of the erosion sites were concentrated in Reach 5 south of Highway 12; a more detailed analysis of the reach should be conducted to determine the cause of this erosion (see Figure 20 for location).
Water quality in the creek is monitored at two locations. Phosphorus load is generally greater at the downstream site, suggesting that the watershed or in-line wetlands are contributing to phosphorus loads in the creek and thus to Tanager Lake. Tanager Lake serves mainly as a pretreatment basin for discharges to Browns Bay. Dissolved oxygen within the stream in the summer months tends to fall below the 5 mg/L State of Minnesota standard for class 2B waters.