West Sutton Lake is one of a group of lakes located on dunal topography near Florence, Oregon (figure 1). Surface inflow is from Mercer Creek and from East Sutton Lake through a narrow 200-foot long five-foot deep channel. Mercer Creek enters from Mercer Lake through a dense willow and peat bog. The Nature Conservancy has classified the bog as a "significant natural area" and its protection is encouraged. Outflow is through Sutton Creek which reaches the Pacific Ocean two miles downstream.
The lakes in this system, like several others on the Oregon Coast, were formed through the blockage of coastal stream valleys by advancing sand dunes. This process occurred following the Pleistocene Epoch, a period in which lower reaches of coastal streams were inundated by rising sea levels. Advancing sand dunes subsequently dammed the mouths of the valleys and formed the lakes (Cooper 1958). The modern lakes in the system (Mercer, West Sutton, and East Sutton) have water surface elevations above sea level, but deepest contours below sea level.
Private land and residences surround much of West Sutton Lake. The Suislaw National Forest maintains a boat launch near the outlet as part of the Sutton Lake Recreation Area. Fishing is good for stocked rainbow trout, native cutthroat trout, smallmouth bass, perch and bluegill. Coho salmon also inhabit the system during portions of their lifecycle.
East Sutton Lake covers a very small percentage of the total watershed area of West Sutton Lake, only 0.9 % (figure 1). The remainder of the watershed is composed of forest, non-forested vegetation (marshland), and urban-agriculture (residential areas) and open water (table1). Only a small portion contains barren land (sand dunes) and urban areas. Forests in the watershed are young and consist of a large percentage of hardwood and mixed hardwood/conifer forest. Road density is similar to other Oregon coastal watersheds included in this study. Precipitation is high on the steep slopes of the lake's coast range watershed. The high point in the watershed is 449 meters at Cape Mountain.
West Sutton Lake is nearly circular in shape, atypical of coastal sand dune dammed lakes (figure 3). The shoreline drop is less dramatic than other dune formed lakes, but still falls to a depth over four meters rather quickly. The deepest point measured, 10.1 m, lies in the flat west central portion of the lake. The mean depth, 5.2 meters, is one meter less than that of East Sutton Lake (table 2). Shallow macrophyte covered areas occur near the south and east shores.
Several water quality parameters were measured in West Sutton Lake during the summer of 2001. A summary is provided in table 2. West Sutton’s trophic state based on both Secchi disc depth and total phosphorus concentration ranged from index values of 44 to 48, the high end of mesotrophy. The trophic state index based on chlorophyll increased throughout the summer from 49 to 63, well within the eutrophic range. This discrepancy between the different indices cannot be explained with the limited data available here, however, it is interesting that the same discrepancy does not occur in the east basin of Sutton Lake. The difference between the basins may be a result of the character of their respective inflows. East Sutton has inflow from extensive marsh area while West Sutton has inflow from both East Sutton and the nutrient rich water of Mercer Lake. Water quality indices are similar to those calculated from data collected by the Oregon Department of Environmental Quality and Portland State University between 1981 and 1996 (figure 4). These data support the classification of West Sutton Lake as mesotrophic to eutrophic.
Oxygen was depleted in the hypolimnion during the two visits when thermal stratification was present. Vertical profiles of temperature, oxygen and other parameters are included below. The mixing depth of the west basin of the lake was considerably deeper than that of the east basin during the stratified season. This is probably due to higher exposure to prevailing winds. Tannic acid equivalents were also lower than in the east basin, likely due to watershed characteristics.
Water clarity and sediment quality were sufficient to support dense beds of submerged macrophytes such as Elodea canadensis, Najas spp., and Utricularia vulgaris. Elodea canadensis, a species that can be problematic, is particularly dense. Floating leaved macrophytes surround shallow areas near the shoreline. Species present include Nymphaea odorata, Nuphar luteum, Brasenia schreberi, and Potomogeton spp.
West Sutton Lake, 2001 Data
Cooper, W. S. 1958. Coastal Sand Dunes of Oregon and Washington. N.Y. Geol. Soc. Am. Memoir 72. New York, NY. 169 pp.