|Lat / Long||53.5833333, -114.1500000|
|Max depth||15.3 m|
|Mean depth||6.95 m|
|Dr. Basin Area||1.5 km2|
|Drainage Basin||North Saskatchewan River Basin|
|Sport Fish||Rainbow Trout|
|TP x||22 µg/L|
|CHLORO x||7.6 µg/L|
|TDS x||123 mg/L|
Lake Eden is a small, deep pothole lake nestled in a sheltered depression in rolling hills west of the city of Edmonton. The lake is located in the County of Parkland. It is a pleasant place to visit on warm summer weekends and is a popular family recreation area. To reach the lake, travel west on Highway 16 until you are 10 km west of the town of Stony Plain, then turn north onto a local road and continue for 2 km. Private roads skirt the lakeshore (FIGURE 1).
All of the land around the lake, except for two road easements, is owned by Lake Eden Summer and Winter Resort. Access to the lake and parking are available for a fee at the resort; free public walk-in access is available as well, but there is no parking area. The only facilities on the lake are those offered by the commercially operated resort; included are 220 campsites, picnic tables, beaches and a boat launch. The only power boats allowed on the lake are those with battery-operated motors (Alta. For. Ld. Wild. 1988). In winter, the resort operates a downhill ski area with several tows. The chalet is open to all, as is a fine network of cross-country ski trails.
Lake Eden was named in the early 1950s by the owner of Lake Eden Fur Farm, which was established on land adjacent to the lake (Holmgren and Holmgren 1976).
Algal growth in Lake Eden is not conspicuous, and the clear water is attractive for swimming and wind surfing. The lake is stocked annually with rainbow trout by Fish and Wildlife Division and sport fishing is popular in both summer and winter. Aquatic plants, which grow densely in some areas, can be a nuisance to shore-based anglers, but because the lake slopes steeply, few plants are encountered beyond a short distance from shore. The use of bait fish and the capture of bait fish is not permitted in Lake Eden (Alta. For. Ld. Wild. 1989).
The drainage basin for Lake Eden is small (1.5 km2, TABLE 1) about 10 times the area of the lake (TABLE 2, FIGURE 1). The terrain is rolling, and hills rise approximately 60 m on all sides of the lake, providing shelter (En. Mines Resour. Can. 1974). The soils in most of the drainage basin are Orthic Gray Luvisols that developed under aspen woodlands on glacial deltaic material (Lindsay et al. 1968). The basin is pocked with small sloughs to the east and south of the lake; soils in these wet areas are Orthic Humic Gleysols. The arability of the soil in the basin is rated as poor to fair. The drainage area is part of the Moist Mixedwood Subregion of the Boreal Mixedwood Ecoregion (Strong and Leggat 1981). The dominant natural vegetation - trembling aspen and balsam poplar, with willow and alder in wetter areas - surrounds most of the lake and covers most of the area north of the lake. Clearing for agricultural crops, mainly grains and canola, has occurred extensively to the south and east of the lake. The area near the lake has been extensively developed by Lake Eden Resort, and includes 30 cottages (12 owned by Lake Eden Resort) that front on the lake, 3 camping areas and a large day-use area.
Lake Eden is irregularly shaped and has 2 basins with similar maximum depths (more than 15 m; FIGURE 2). The lake bottom slopes quite steeply on all sides except in the three bays along the north shore and along the south shore near the narrows. The littoral zone extends to approximately 5 m (R.L. & L. Envir. Serv. Ltd. 1987) and includes about 37% of the surface area of the lake (FIGURE 3). The shoreline is dominated by fibrous organic material. Sand has been brought in to create a beach at the resort at the east end and is present in a small area on the north shore. As in most Alberta lakes, the bottom underlying the deeper areas of the lake is soft organic material (R.L. & L. Envir. Serv. Ltd. 1987).
Lake Eden is a pothole; it has no channelized inlet and no surface outlet. Groundwater inflow and outflow have never been measured, but likely provide a significant amount to the water balance. The lake level has been monitored 4 times a year since 1968 (FIGURE 4). Since 1975, the level has fluctuated a maximum of 0.6 m.
Lake Eden was the subject of intensive water quality studies by the University of Alberta from May through July 1981, May 1982 through March 1983 and in March 1986 (Prepas and Babin n.d.; Prepas 1983[a]; 1983[b]; Prepas and Trew 1983; Babin 1984; Prepas and Vickery 1984; Babin and Prepas 1985).
The lake has very fresh water; the salt content (total dissolved solids = 123 mg/L) (TABLE 3) is the lowest of the 27 lakes in the Edmonton-Athabasca-Beaver River area studied by Prepas and Trew (1983). The dominant ions are bicarbonate and calcium; the alkalinity and hardness are both relatively low for prairie lakes. The water is neither turbid nor coloured.
Although the thermal stratification patterns in Lake Eden are unusual compared to those in larger and windier lakes in Alberta, they are similar to other small and relatively deep lakes in central Alberta. Lake Eden does not mix to any appreciable extent in spring, nor does it mix completely in autumn. The lake is strongly thermally stratified in summer, with only a thin (up to 3 m by July) mixed layer at the surface (FIGURE 5). In 1982, dissolved oxygen concentrations below a depth of 9 m were less than 1 mg/L from ice-out in early May through mid-October (FIGURE 6). The water near the bottom was anoxic throughout this period. The lake did not mix thoroughly in the autumn but some dissolved oxygen did reach the bottom sediments just before freeze-up. Overwinter dissolved oxygen consumption rates in 1982/83 were relatively low (0.331 g of 02/ m2 per day), reflecting the relatively low algal productivity in this lake (Babin and Prepas 1985). Dissolved oxygen concentrations in the upper strata were high enough to support fish, but the bottom water was anoxic from early January until spring.
Phosphorus is released from the anoxic sediments in Lake Eden throughout the period of winter ice cover. In spring, some of the phosphorus is mixed into the upper water of the lake and the total phosphorus concentration in the euphotic zone reaches a maximum in May (FIGURE 7). Algal production (as indicated by chlorophyll a concentration) in the upper water also peaks at this time. This brief spring algal bloom consumes much of the phosphorus in the upper water of the lake, then both algae and phosphorus precipitate to the bottom when the algae die. Phosphorus moves into the upper layer of the lake from the sediments within the littoral zone at an estimated rate of 1.1 mg/m2 per day from June through August (Shaw and Prepas 1989). However, thermal stratification restricts the movement of phosphorus from below the thermocline to the upper water. It has been estimated that phosphorus is transported from the deep water in Lake Eden to the surface water at the very slow rate of 0.03 mg/m2 per day. Therefore, the concentrations of total phosphorus and chlorophyll a in the euphotic zone decline rapidly soon after spring thaw, then more slowly throughout the summer (FIGURE 7). After the spring bloom, the surface water is very clear and Secchi depths are close to 6 m throughout the summer.
While the total phosphorus concentration in the epilimnion is low and decreasing all summer, the situation is quite different below the thermocline. In the lower layer of the lake, the dissolved oxygen concentration is low or zero and phosphorus is released fairly rapidly from the bottom sediment into the overlying water. In 1982, the total phosphorus concentration at a depth of 9 m was between 42 and 67 µg/L from May until mid-September (Prepas 1983[a]), approximately 3 times the concentrations in the top 2 m of the lake as shown in Figure 7. Because sufficient light for algal growth penetrates to approximately 9 m in Lake Eden, it is near this depth that conditions are optimal for algal growth; chlorophyll a concentrations at this depth ranged from 15.2 to 43.0 µg/L, approximately 4 times the concentration in the top layer of the lake. It is this sharp vertical gradient in chlorophyll a concentrations that explains the difference in mean chlorophyll a reported for 1981 and 1982 (TABLE 4). Small differences in estimates of the depth of the euphotic zone mean that the layer of dense algal growth is sometimes included in the sample and sometimes missed.
In late October, thermal stratification breaks down and some of the phosphorus-rich water in the lower part of the lake mixes into the upper layers and there is, potentially, a fall algal bloom near the surface. Under ice, total phosphorus concentrations build up when the dissolved oxygen concentration is low; in March 1983, total phosphorus concentrations ranged from 14 µg/L at the surface to 183 µg/L over the bottom sediments (Prepas and Babin n.d.). Lake Eden is classified as a mesotrophic lake.
There are no data on the species of algae in Lake Eden.
The aquatic vegetation in Lake Eden was surveyed for Fish and Wildlife Division in 1986 (TABLE 5). The shallow inshore areas support emergent vegetation dominated by cattails (Typha latifolia) and sedges (Carex spp.). The main submergent species were Richardson pondweed (Potamogeton richardsonii), flat-stemmed pondweed (P. zosteriformis) and northern watermilfoil (Myriophyllum ex-albescens).
The zooplankton was sampled in 1981 and 1982 (Prepas 1983[a]). The dominant cladocerans were a small Daphnia species (D. thorata or D. galeata mendotae), and a Ceriodaphnia species (C. lacustris or C. reticulata). The copepods Diacyclops bicuspidatus thomasi and Diaptomus oregonensis and the phantom midge Chaoborus sp. were also noted. Benthic invertebrates have not been sampled in Lake Eden.
The indigenous fish community of Lake Eden likely consisted of northern pike, yellow perch, brook stickleback and "shiners" (species unknown) (Alta. For. Ld. Wild. n.d.). The stocking history of Lake Eden (Alta. For. Ld. Wild. n.d.) began in 1953 when walleye were introduced as eyed-eggs following a severe winterkill in 1952/53 which eliminated pike and perch. The walleye did not survive, and in 1954, rainbow trout were introduced. In 1956, northern pike were introduced; the population was augmented by more pike in 1957, 1958 and 1959. As well, perch were stocked in 1959. No fish were added from 1960 to 1966. Dissolved oxygen concentrations fell to less than 0.8 mg/L in March 1967, causing a severe fish kill; no fish were caught by test-netting in the following July. Perch were stocked in the summer of 1967 but apparently failed to thrive. From 1967 to 1982, rainbow trout were stocked annually and provided a moderate sport fishery. Brook trout were stocked once, in 1971. Stocking was suspended in 1983, then resumed in 1985 when free walk-in access to the lake was provided. Annual stocking with rainbow trout has continued since then. Approximately 24,000 fingerlings are added each year and support a moderate sport fishery. There is no commercial or domestic fishery on the lake.
There is no readily available information on wildlife at Lake Eden. Good waterfowl habitat is provided by the rooted vegetation along the shoreline.
J.M. Crosby and E.E. Prepas
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