Wabamun Lake NAM-45

Riparian Nation(s) Canada
Surface Area 82 km2 Mean Depth 6.3 m Volume 0.51 km3
Shoreline 57.3 km Catchment Area 259 km2 Residence Time 100 yr
Frozen Period Nov-Apr Mixing Type Polymictic Morphogenesis/Dam
Related Info/Site

Description

Lake Wabamun, one of the best-known lakes of Alberta, lies 60 km west of Edmonton. The name "Wabamun" is a Cree word meaning mirror.

Lake Wabamun is a large shallow lake that is 19.2 km long and 6.6 km wide. Its long fetch along the prevailing wind results in heavy wave action at times. The deepest area reaching 11 m is at the western end. There are natural beaches along much of the shoreline, but emergent vegetation restricts their use. The littoral zone (<5 m depth) includes 31% of lake bottom. Sandy areas are found at depths less than 2 m with soft clay or organic sediments over most of the lake bottom.

The range of water level fluctuation since the earliest records (1915; continuous records since 1933) amounts to about 1.4 m, although normal range is about 1 m on approximately a ten-year cycle. Since 1912 a number of control structures have been built and subsequently destroyed on one or the other of the two outlet creeks. As of 1989 investigations were underway to determine an elevation for a suitable control structure.

Despite abundant aquatic vegetation along shorelines and in bays, the water in L. Wabamun is often fairly clear and blue-green algal blooms are rare. The popular opinion is that the nuisance growth of an aquatic weed, Elodea canadensis, which was not observed in the lake before 1968, caused poor water quality. The cooling water discharge from two power plants on the shore were implicated as the cause. Since the diversion of cooling water to a large cooling pond in 1975, Elodea began to decline simultaneously, and is now rare in the lake, except near the cooling water discharge canal from the 3rd power plant.

The drainage basin surrounding the lake is about three times as wide as the lake surface; the terrain is gently rolling to undulating hills to the south of the lake. The native vegetation is dominated by trembling aspen, balsam poplar and willow with white spruce in undisturbed areas. About half of the land is used for agriculture. Coal is strip-mined extensively north and south of the lake. As coal excavation moves west, the mined-out land is reclaimed, primarily for agricultural purposes, but reclamation efforts will include recontouring and the return of native vegetation.

At least 35 drainage courses convey runoff and groundwater to the lake, of which the seven largest account for about 70% of the total runoff. Mine drainage enters the lake after settling in several ponds. Two outlets, one of which is a man-made through-cut, join to form Wabamun Creek, which flows intermittently toward the North Saskatchewan River.

The community of Wabamun was established in 1912. The first coal mines in the lake's watershed began underground operations in 1910; strip mining began in 1948. Three power plants have been built by TransAlta Utilities to take advantage of the abundant supply of local coal. At present only one (started operation in 1983) uses lake water for cooling, and heated effluent is returned to Kapasiwin Bay, where a large portion of the bay area remains ice- free in winter.

The provincial park located on Moonlight Bay is a focus of activity on warm summer weekends, such as boating, swimming, fishing, camping, and hiking. Fishing is one of the most popular activities on the lake. In summer, fishing is often excellent for northern pike and increasingly so for walleye. In winter, ice-fishing for whitefish draws hundreds of fishermen on mild weekends and large pike may be taken from the outlet canal at the power plant (4, 5, 11, 12).

Photo of Wabamun Lake
Photo: P. Mitchell