2.2.1 Topography and Drainage
Most of the subwatershed is located within the Emmons-Faribault moraine region, a landscape type formed by glacial till dumped at the edge of glaciers. Rugged hills or “knobs” and deep irregular depressions called “kettles” dominate this type of landscape. The many bays, points, and islands of Lake Minnetonka are formed from submerged knobs and kettles formed by melted blocks of glacial ice. One of the sharpest moraines to occur in Minnesota, the Eastern St. Croix moraine, ends along Lake Minnetonka’s southeastern shore. The northwestern subwatershed is located within the Lonsdale-Lerdal till region, an area characterized by thinly spread glacial drift and circular, level-topped hills with low slopes, small streams, numerous lakes and peat bogs.
The dominant water feature in the subwatershed is Lake Minnetonka. Drainage is conveyed from the upper subwatershed to the lake through several streams, including Gleason Creek, Long Lake Creek, Classen Creek, Painter Creek, and Six Mile Creek, as well as through smaller channels or storm sewer. The 2003 MCWD Hydrologic, Hydraulic, and Pollutant Loading Study (HHPLS) subdivided the Lake Minnetonka direct drainage subwatershed into 26 subwatershed units and the Minor Subwatersheds into 19 drainage areas that include from one to six subwatershed units (see Figure 2). The Minor Subwatersheds are small drainage areas that are small relative to the 11 major subwatersheds, and do not contain lakes that were modeled for water quality purposes. Many of these minor subwatersheds include smaller lakes or ponds.
The subwatershed outlets through a control structure on Grays Bay into Minnehaha Creek.