|Lat / Long||52.9500000, -114.3666667|
|Max depth||35 m|
|Mean depth||15.7 m|
|Dr. Basin Area||7.12 km2|
|Drainage Basin||North Saskatchewan River Basin|
|Boat Launch||Hand/Small Boat|
|Sport Fish||Northern Pike, Rainbow Trout, Yellow Perch|
|TP x||14 µg/L|
|CHLORO x||1.8 µg/L|
|TDS x||188 mg/L|
Tiny, sparkling Twin Lake is located 115 km southwest of the city of Edmonton in the County of Wetaskiwin. From Edmonton, take Highway 2 south to Highway 13, then travel west on Highway 13 past Pigeon Lake. Twin Lake is 3 km east of the hamlet of Winfield, just south of Highway 13. As the name implies, there are two lakes at this location, often referred to as West and East Twin or Twin Lakes. These two lakes are separated by a distance of less than 700 m; both have clear water. West Twin is relatively deep and is referred to in this chapter as Twin Lake (FIGURE 1), whereas East Twin is extremely shallow and will be discussed only in reference to the deeper lake.
Twin Lake is located in a treed area; it is an idyllic location for picnics, quiet camping and fishing. A campground with 60 sites is located on the north shore of the lake and along the road connecting the two lakes (FIGURE 2). The campground has firewood, pump water and a picnic area (Walker 1988) and is maintained by the County of Wetaskiwin. A small boat can be launched at the gravel boat launch on the north side; gasoline motors are prohibited (Alta. For. Ld. Wild. 1988). A soft mud bottom discourages swimming from the shoreline, although gravel added at the east end has improved shore access for swimmers. The lake water is excellent for swimming and the lake is one of the best in Alberta for SCUBA diving (Conroy Club and Yeoford Ladies Club 1973). The lake is stocked with catchable size rainbow trout. Although provincial fishing regulations apply, there are no specific regulations for Twin Lake (Alta. For. Ld. Wild. 1989).
The drainage basin of Twin Lake is mostly forested (TABLE 1). White spruce predominate in upland areas, black spruce and tamarack predominate in lower areas and white birch, lodgepole pine, balsam poplar and trembling aspen are found throughout. Some areas in the southwest corner of the drainage basin are cleared for agriculture; the agricultural capacity of soils in this corner are rated as fair to fairly good (Lindsay et al. 1968). All of the land directly around the lake is owned by the Crown. The only development near both lakes is the campground.
Two intermittent streams flow into Twin Lake through culverts from East Twin Lake (Smith 1982). The main inflow from East Twin Lake enters on the east side of Twin Lake and the second one flows occasionally into the north side. A third stream flows through a tiny unnamed lake in the southeast part of the drainage basin and into the southeast corner of Twin Lake (FIGURE 1).
Twin Lake is located near a topographic divide between three major river basins: the North Saskatchewan, the Battle and the Red Deer. The outflow stream from the lake, a fork of Poplar Creek, flows northwest from the lake (FIGURE 2) and eventually enters the North Saskatchewan River 25 km east of Drayton Valley.
The water level of Twin Lake has been recorded since October 1968 (FIGURE 3). Water levels dropped a full metre, from a high of 920.0 m when records began, to 919.0 m in February 1981. Later in 1981, water levels rebounded, and in recent years, they have fluctuated around 919.5 m. A beaver dam, which extends across the outlet, controls lake water levels.
Changes in the lake's area and capacity, to an elevation of 919.18 m, are shown in Figure 4.
The water quality of Twin Lake was studied in the summers of 1980 and 1981, and from May 1982 through March 1983 by researchers at the University of Alberta (Prepas et al. n.d.; Prepas 1983[a]; 1983[b]; 1983[c]; Prepas and Trew 1983; Babin 1984; Prepas and Vickery 1984[a]; 1984[b]; Babin and Prepas 1985).
Twin Lake has hard water; the dominant ions are bicarbonate and calcium (TABLE 3). The water is moderately coloured, but not turbid. Due to the lake's relatively high elevation (919 m), the surface water temperatures in summer are about 4°C cooler than many other small lakes in central Alberta. The water is strongly thermally stratified in summer (FIGURE 5). The lake is sheltered by trees and by relatively steep banks, particularly on the south side. Given the lake depth and protection from the wind, thermal mixing is weak and dissolved oxygen concentrations are strongly stratified year-round (FIGURE 6). Dissolved oxygen depletion rates were measured in the hypolimnion in the summer of 1980 (0.312 g O2/m2 per day), and under ice cover in the winter of 1982/83 (0.193 g O2/m2 per day). These rates are low and reflect, at least partially, low algal productivity in the lake.
Twin Lake is oligotrophic. In summer, total phosphorus typically falls below 10 µg/L and chlorophyll a concentrations are generally below 2 µg/L (TABLE 4). Total phosphorus concentrations in the surface waters are highest in spring (FIGURE 7) and late fall. These maxima are caused by the mixing of water from the phosphorus-rich hypolimnion throughout the lake during overturn. In September 1982, total phosphorus concentrations reached 190 µg/L over the bottom sediments and 50 µg/L at 13 m below the surface. By March 1983, total phosphorus concentrations had reached 30 µg/L in the surface waters and 400 µg/L over the bottom sediments. Detailed phosphorus budgets provided no evidence that phosphorus from bottom sediments was recycled into the trophogenic zone of Twin Lake (Shaw and Prepas 1989). This is a very unusual situation in an Alberta lake. The phosphorus concentrations in the surface waters of Twin Lake are unusually low and the calcium concentrations are unusually high for a lake in central Alberta (Tables 3, 4). Twin may be a lake where phosphorus released from the bottom sediments is not available for algal production due to coprecipitation with iron and/or calcium.
The water quality of East Twin Lake was measured once in August 1980. Although it was generally similar to that in Twin Lake, the water in East Twin was less coloured, and open-water phytoplankton levels were one-third those recorded for the deeper lake. The shallow lake has a rich benthic algal community.
There are no data on the plants in Twin Lake.
The zooplankton was sampled at various intervals from May through September, from 1980 to 1982 (Prepas et al. n.d.; Prepas 1983[c]; Prepas and Vickery 1984[a]). The zooplankton biomass was relatively high: 15% of the total phosphorus pool in the trophogenic zone. The dominant species in the summers of 1981 and 1982 were Daphnia pulex/pulicaria, Diaptomus leptopus, Diacyclops bicuspidatus thomasi and Chaoborus sp.
There are no data on benthic invertebrates in Twin Lake.
Four species of fish have been recorded in the lake. Northern pike, burbot, and yellow perch are native, whereas rainbow trout has been introduced. Forage fish and suckers are present, but species have not been identified.
From 1964 through 1966, the lake was stocked with kokanee salmon (Alta. For. Ld. Wild. n.d.), but few, if any, salmon were caught subsequently. From 1969 through 1975, an average of 13,000 yearling rainbow trout were introduced each year. This program was halted because few or none of the small trout survived, likely due to predation by northern pike. Fish and Wildlife Division considered treating both Twin lakes and the inlet stream at the southeast corner with rotenone, to remove the northern pike (Smith 1982), but this treatment was not carried out. Instead, a program of stocking adult rainbow trout was initiated in 1984. An annual average of 480 trout were planted from 1984 through 1988. The program of stocking catchable size trout has been very successful and will likely continue in Twin Lake, but only as large trout become available (Lowe 1988).
The distribution of northern pike in Twin Lake was studied by divers using SCUBA in 1980 (Chapman and Mackay 1984). During summer, when the water was thermally stratified, most pike (81%) observed by divers were in the top 2 m of water, and only 1% were below a depth of 4 m. Smaller pike (greater than 25-cm standard length) were found more frequently in the top 2 m of water than larger pike. In the autumn, very few pike were observed, and those that were seen were at depths of less than 2 m.
Mallards, Gadwall, Common Goldeneye and Bufflehead nest on the lake. Common Loons are seen on the lake in spring (Alta. For. Ld. Wild. n.d.).
Alberta Environment. n.d.[a]. Tech. Serv. Div., Hydrol. Br. Unpubl. data, Edmonton.
-----. n.d.[b]. Tech. Serv. Div., Surv. Br. Unpubl. data, Edmonton.
Alberta Forestry, Lands and Wildlife. n.d. Fish Wild. Div. Unpubl. data, Edmonton.
-----. 1988. Boating in Alberta. Fish Wild. Div., Edmonton.
-----. 1989. Guide to sportfishing. Fish Wild. Div., Edmonton.
Alberta Research Council. 1972. Geological map of Alberta. Nat. Resour. Div., Alta. Geol. Surv., Edmonton.
Babin, J. 1984. Winter oxygen depletion in temperate zone lakes. MSc thesis. Univ. Alta., Edmonton.
----- and E.E. Prepas. 1985. Modelling winter oxygen depletion rates in ice-covered temperate zone lakes in Canada. Can. J. Fish. Aquat. Sci. 42:239-249.
Chapman, C.A. and W.C. Mackay. 1984. Direct observation of habitat utilization by northern pike. Copeia:255-258.
Conroy Club and Yeoford Ladies Club. ca 1973. Trail blazers. Conroy Club Yeoford Ladies Club, Winfield.
Energy, Mines and Resources Canada. 1975. National topographic series 1:50000 83B/16 (1975). Surv. Map. Br., Ottawa.
Environment Canada. 1982. Canadian climate normals, Vol. 7: Bright sunshine (1951-1980). Prep. by Atm. Envir. Serv. Supply Serv. Can., Ottawa.
Lindsay, J.D., W. Odynsky, J.W. Peters and W.E. Bowser. 1968. Soil survey of the Buck Lake (NE 83B) and Wabamun Lake (E1/2 83G) areas. Alta. Soil Surv. Rep. No. 24, Univ. Alta. Bull. No. SS-7, Alta. Res. Counc. Rep. No. 87. Univ. Alta., Edmonton.
Lowe, D. 1988. Alta. For. Ld. Wild., Fish Wild. Div., Red Deer. Pers. comm.
Prepas, E.E. 1983[a]. Orthophosphate turnover time in shallow productive lakes. Can. J. Fish. Aquat. Sci. 40:1412-1418.
-----. 1983[b]. Total dissolved solids as a predictor of lake biomass and productivity. Can. J. Fish. Aquat. Sci. 40:92-95.
-----. 1983[c]. The influence of phosphorus and zooplankton on chlorophyll levels in Alberta lakes. Prep. for Alta. Envir., Res. Mgt. Div. Rep. 83/23, Edmonton.
----- and D.O. Trew. 1983. Evaluation of the phosphorus-chlorophyll relationship for lakes off the Precambrian Shield in western Canada. Can. J. Fish. Aquat. Sci. 40:27-35.
Prepas, E.E. and J. Vickery. 1984[a]. The contribution of particulate phosphorus (>250 µm) to the total phosphorus pool in lake water. Can. J. Fish. Aquat. Sci. 41:351-363.
-----. 1984[b]. Seasonal changes in total phosphorus and the role of internal loading in western Canadian lakes. Verh. Internat. Verein. Limnol. 223:303-308.
Prepas, E.E., I. Wisheu and J. Babin. n.d. Univ. Alta, Dept. Zool. Unpubl. data, Edmonton.
Shaw, J.F.H. and E.E. Prepas. 1989. Potential significance of phosphorus release from shallow sediments of deep Alberta lakes. ms submitted to Limnol. Oceanogr.
Smith, T. 1982. Memorandum to C. Ladd on West Twin Lake rehabilitation. Alta. En. Nat. Resour., Fish Wild. Div., Red Deer.
Strong, W.L. and K.R. Leggat. 1981. Ecoregions of Alberta. Alta. En. Nat. Resour., Resour. Eval. Plan. Div., Edmonton.
Walker, G. 1988. Co. Wetaskiwin, Wetaskiwin. Pers. comm.