|Map Sheets||73D/3, 6|
|Lat / Long||56.4606263, -111.1458193|
|Max depth||7.2 m|
|Mean depth||3.9 m|
|Dr. Basin Area||232 km2|
|Drainage Basin||Athabasca River Basin|
|Sport Fish||Northern Pike, Lake Whitefish, Walleye, Yellow Perch|
|TP x||23 µg/L|
|CHLORO x||6.2 µg/L|
|TDS x||63 mg/L|
Gregoire Lake is an important recreational lake for residents of the city of Fort McMurray. The lake is located in Improvement District No. 18 (North), about 30 km southeast of Fort McMurray. To reach the lake from the city, take Highway 63 south and then Secondary Road 881 southeast. Gregoire Lake Provincial Park, situated on the northwestern shore (FIGURE 1), is the largest recreational facility at the lake and is the only provincial park in the Fort McMurray area. The hamlet of Anzac is situated on the eastern shore.
Until the 1940s, Gregoire Lake was known as Willow Lake (Alta. Rec. Parks n.d.). It was renamed for its outlet, the Gregoire River, which was named for an early settler (Geog. Bd. Can. 1928).
Woodland Cree and Chipewyan Indians have lived in the area since before the arrival of white explorers. During the early 1900s, there was an Indian settlement on the northwestern shore of the lake. At present, the Fort McMurray Band of Cree and Chipewyan Indians has three treaty reserves on the lake, which cover a total of 1 304 ha. They are Gregoire Lake Reserves 176, 176A and 176B (Alta. Native Aff. 1986). A 1984 census indicated 140 band members, but most of them do not live on the reserves.
The history of the general area involves many of Canada's first explorers. The Athabasca country was opened to the fur trade after 1778, when Peter Pond discovered the Methy Portage to the Clearwater River (Lombard North Group 1974). In 1789, Alexander Mackenzie first travelled the Athabasca River on his journeys to the Arctic and Pacific oceans. In 1799, David Thompson travelled the Athabasca-Clearwater River system, and in 1819, Sir John Franklin passed through the Fort McMurray area on an overland journey to the arctic.
The Gregoire Lake area was surveyed in about 1916 by the Australia-New Zealand Army Corps (ANZAC), which named the hamlet of Anzac. Anzac became a stopover on the Northern Alberta Railway route between Cheecham Siding to the south, and the McInnis fish plant in Waterways Station, near Fort McMurray. The local fishery was centred at Garson Lake, to the east of Anzac on the Saskatchewan border (Alta. Rec. Parks n.d.).
There are several public and private recreational facilities on Gregoire Lake. Gregoire Lake Provincial Park is located on the northwestern shore (FIGURE 2). It was officially opened in 1973 (Finlay and Finlay 1987). Day-use services are provided year-round and camping services are provided from 1 May to Thanksgiving Day. Park facilities include 140 campsites (60 with electricity), a group camping area, tap water, a sewage disposal facility, a picnic area, a beach, a boat launch, boat rentals and walking trails. During summer, the main activities of park visitors are swimming, motor boating, picnicking, camping and fishing. During winter, visitors enjoy cross-country skiing and ice fishing. Part of the provincial park, the Anzac Day-use Area, is located on the eastern shore near the hamlet. Facilities include picnic tables, a beach, a dock and an informal boat launch. There are no boating regulations over most of the lake, but in designated swimming areas, boats are prohibited, and in posted areas, power boats are subject to a maximum speed of 12 km/hour (Alta. For. Ld. Wild. 1988).
Improvement District No. 18 (North) maintains Windsurfer Beach on land leased from the province. The area runs east from Reserve 176, past the Gregoire River. Near the river, there are picnic tables, firepits and about 20 primitive campsites; farther west, near the reserve boundary, there is a rocky beach used as a wind surfer staging area, and a few picnic tables. The only commercial campground and day-use area at the lake is operated by the Fort McMurray Band; it is located on Reserve 176A on the eastern shore. Private camps at the lake include Camp Yogi, located north of the Anzac Day-use Area, and Camp Manytrees, located north of Indian Reserve 176A (FIGURE 2). Camp Yogi is operated by the nonprofit Camp Yogi Society and is used by community groups for social gatherings, camping and outdoor education. As well, a recreational lease is held by the Fort McMurray Regional Camping Association on 32 ha of Crown land that lies between Reserve 176A and the subdivision on the western shore.
Most of the shoreland around the lake belongs to the Crown or to the Indian reserves. A point of land at the southwest corner of the lake, at the inlet of Surmont Creek (FIGURE 2), was reserved as a natural area in 1966, and currently has protected status (Alta. For. Ld. Wild. 1987). Patented land includes a half section of land between Reserves 176 and 176A, subdivided land along the eastern shore south of the provincial park, and land within Anzac.
Aquatic vegetation is abundant around the shoreline of Gregoire Lake and blue-green algae sometimes form blooms during summer. The lake supports a domestic fishery and a popular sport fishery for walleye, northern pike and yellow perch. The Gregoire River and Gregoire Lake and its tributary streams are closed to fishing for a designated period during April and May each year (Alta. For. Ld. Wild. 1989).
Gregoire Lake has a large drainage basin that is about 9 times the size of the lake (Tables 1, 2). Most water drains into the lake from the south via Surmont Creek and its tributaries. As well, there are six small streams that enter the lake at various points (FIGURE 1). The outflow, the Gregoire River, eventually flows into the Athabasca River via the Clearwater and Christina rivers.
Gregoire Lake's watershed is part of the Boreal Mixedwood Ecoregion and the Interior Plains physiographic division. Turchenek and Lindsay (1982) subdivided the Gregoire Lake drainage basin into three ecodistricts based on relief, geology, geomorphology and vegetation. The ecodistricts are the Carson Plain, the Cheecham Hills Escarpment and the House Plain.
The Garson Plain is an undulating to hummocky plain that surrounds the lake on the northern, southern and western shores. Surficial material is predominantly glacial till underlain by the Grand Rapids and Clearwater bedrock formations (TABLE 1). Elevations on the plain range from 450 to 500 m. Soils are mostly moderately well-drained to well-drained Orthic Gray Luvisols and poorly to very poorly drained Fibric and Terric Mesisols. Around the lakeshore, most of the vegetation is deciduous forest composed primarily of trembling aspen, and secondarily of balsam poplar and white birch (Lombard North Group 1974). Occasional areas of deciduous/jack pine forest and deciduous/spruce/feathermoss communities also occur. Several areas of black spruce/tamarack bog are located along the southern shore and to the north of the lake.
The Cheecham Hills Escarpment is the most prominent feature of the drainage basin. It is a highly dissected, north-facing escarpment that lies between Indian Reserve 176 and Surmont Lake. Surficial material is colluvium, and shales of the Joli Fou and La Biche bedrock formations are exposed in the deeper valleys. Elevations range from 550 to 750 m and slopes range from 2 to 30%. Land near the streams on this escarpment is rough and broken, with steep slopes (greater than 15%). The main soils are well-drained Orthic Gray Luvisols and Orthic Regosols, with small deposits of Organics. Vegetation consists mainly of deciduous forest composed of trembling aspen, balsam poplar and white birch, with smaller areas of deciduous/spruce/feathermoss forest and deciduous/spruce/jack pine forest (Lombard North Group 1974).
The House Plain is an undulating to hummocky plain that occupies the most southerly portion of the drainage basin. Kinosis till, the main surficial material, overlies the shales of the La Biche Formation. Elevations range from 650 to 750 m and slopes range from 0 to 15%. Well-drained Orthic Gray Luvisols and poorly to very poorly drained Fibric, Terric and Typic Mesisols are the dominant soils. Black spruce forest and wetland fen communities are common throughout the area, with mixed coniferous, trembling aspen and jack pine forests on upland sites.
There is no agricultural activity in the drainage basin. Industrial development is centred on resource extraction and most of the land in the drainage basin is held under bituminous sands leases or oil sands leases. The Amoco In-Situ Oil Plant is located on Gregoire Lake Indian Reserve No. 176 (Lombard North Group 1974; Murray V. Jones Assoc. Ltd. 1978).
Gregoire Lake is a large, shallow lake with a surface area of almost 26 km2 (TABLE 2). The deepest water (7.2 m) is located in the western half of the single, large basin, and an island is located near the eastern shore (FIGURE 2). The shoreline is composed mainly of rubble and gravel, with the exception of three large, sandy beaches (Bradley n.d.).
The elevation of Gregoire Lake has been monitored since 1975 (FIGURE 3). The historic minimum level (475.01 m) was recorded in October 1981 and the maximum level (475.88 m) was recorded in May 1985. This is a range of 0.87 m. Figure 4 illustrates changes in the lake's area and capacity that occur with fluctuations in the water level. In 1973, Alberta Environment built a sheet-pile weir on the outlet to stabilize lake levels (TABLE 2). The control structure includes a 1.2-m-wide step-pool fish ladder which is operated by Fish and Wildlife Division. The target elevation for the lake was set at 475.27 m at the request of Alberta Recreation and Parks (Alta. Envir. n.d.[a]).
Gregoire Lake's water quality was sampled by Alberta Environment between 1976 and 1983 under the Alberta Oil Sands Environmental Research Program, on 15 August 1988 and during 1989 under a joint sampling program with Alberta Recreation and Parks (Alta. Envir. n.d.[b]).
The lake has fresh water, with alkalinity, hardness and pH values that are very low for an Alberta lake (TABLE 3). The dominant ions are calcium and bicarbonate.
Gregoire Lake is typical of many shallow Alberta lakes: the water column is well-mixed by wind during the open-water season (FIGURE 5), and is thermally stratified on calm days. Dissolved oxygen concentrations during the open-water season are generally high and quite uniform from surface to bottom (FIGURE 6). In February 1980, under-ice dissolved oxygen levels throughout the water column declined to less than 3 mg/L.
The limited chlorophyll a data available suggest that Gregoire Lake is eutrophic. In 1979, the maximum chlorophyll a concentration was 69.9 µg/L, recorded in August (FIGURE 7), and the average chlorophyll a value for the open-water season was 34.4 µg/L (TABLE 4). The chlorophyll a concentration recorded in August 1988, however, was much lower (13.2 µg/L), as was the average concentration in 1989 (5.3 µg/L). The water was quite murky-the average Secchi transparency was only 1.3 m in 1979 and 2.4 m in 1989. Total phosphorus concentrations are not available for 1979, but the 1989 average was 21 µg/ L.
The phytoplankton in Gregoire Lake was studied by Alberta Environment occasionally from July to October 1977 and intensively from March to November 1980 (Beliveau and Furnell 1980). More than 70 species were identified, but biomass was not calculated for each species. The biomass of the major algal groups was measured as total cell volume per square metre. Blue-greens (Cyanophyta) were the major group measured on 7 of the 11 sampling dates. In late March and from June to September, blue-greens accounted for 44 to 83% of the total cell volume. Cryptophytes were dominant in early March and early May, and diatoms formed 91 to 97% of the total volume in October and early November.
Alberta Environment surveyed the macrophyte community in July 1981 (FIGURE 8). Dense beds of the emergent species horsetail (Equisetum spp.), yellow water lily (Nuphar variegatum), bulrush (Scirpus spp.) and common cattail (Typha latifolia) were observed growing in the eastern bay and along the western shore. The most abundant submergent plants were various species of pondweed (Potamogeton spp.). The abundance of aquatic plants was lowest along the northern shore and along a section of the southern shore.
There are no data available for the zooplankton community.
In May 1969, Fish and Wildlife Division briefly surveyed the benthic invertebrates (Bradley n.d.). Thirty-four samples were taken with a dredge at unspecified depths over the entire lake bottom. Almost 90% of the volume was made up of midge larvae (Chironomidae).
Eight species of fish are known to inhabit Gregoire Lake: walleye, northern pike, yellow perch, lake whitefish, cisco, burbot, spottail shiner and longnose sucker (Bradley n.d.). Lake whitefish are infested with cysts of the tapeworm Triaenophorus crassus. The lake supports a domestic fishery and a popular recreational fishery. A small commercial fishery operated from 1944 to 1966 (Alta. Rec. Parks Wild. 1976). There are no catch data available for the domestic fishery. Between 1985/86 and 1988/89, no domestic licences were issued for the first 2 years, 16 licences were issued in 1987/88 and 9 licences were issued in 1988/89 (Alta. For. Ld. Wild. n.d.).
A creel survey of the sport fishery at Gregoire Lake was conducted during 1984 (TABLE 5). It was estimated that 5,358 anglers visited the lake and fished for a total of 16,181 hours. Anglers did not actively fish for pike, because the preferred species was walleye. Consequently, 75% of the pike caught were released. The average harvest/angler-hour for 22 lakes in the Northeast Region surveyed between 1984 and 1987 was 0.10 for walleye, 0.22 for northern pike and 0.32 foryellow perch (Alta. For. Ld. Wild. n.d.). In comparison, the harvest per unit effort at Gregoire Lake was more than twice the regional average for walleye (0.21 walleye/angler-hour) and slightly less than average for northern pike (0.17 pike/angler-hour). The yellow perch harvest/angler-hour (0.01) was well below average. Only 32% of the anglers interviewed at Gregoire Lake caught one or more walleye and 28% caught one or more pike. The largest harvests of all species were taken during late June and, for yellow perch, during late July as well (Sullivan 1985). In comparison to six other Northeast Region lakes surveyed during 1984, Gregoire Lake received low to moderate angling pressure (4.8 angler-hours/ha).
Although Gregoire Lake is used as a staging area for migrating waterfowl, its potential is low compared to other lakes in the area such as Gordon and Garson lakes (Lombard North Group 1974; Finlay and Finlay 1987). Approximately 126 bird species have been sighted in Gregoire Lake Provincial Park; 118 of these were summer residents or were found nesting (Gregg 1976). Spruce Grouse, Gray Jays and Magnolia and Palm warblers are commonly seen in black spruce bogs and waterfowl feed and nest in marsh communities.
Wildlife data specific to Gregoire Lake and its drainage basin are limited. Wildlife species in the Fort McMurray region were summarized in 1974 (Lombard North Group 1974). Fur-bearing animals commonly found in the watershed are beaver, lynx, mink, muskrats, red fox, otters, wolves, coyotes and weasels. The principal ungulates are moose, deer and caribou.
Alberta Environment. n.d.[a]. Devel. Op. Div. Unpubl. data, Edmonton.
-----. n.d.[b]. Envir. Assess. Div., Envir. Qlty. Monit. Br. Unpubl. data, Edmonton.
-----. n.d.[c]. Tech. Serv. Div., Hydrol. Br. Unpubl. data, Edmonton.
-----. n.d.[d]. Tech. Serv. Div., Surv. Br. Unpubl. data, Edmonton.
-----. n.d.[e]. Water Resour. Admin. Div., Dam Safety Br. Unpubl. data, Edmonton.
Alberta Forestry, Lands and Wildlife. n.d. Fish Wild. Div. Unpubl. data, Edmonton.
-----. 1987. A summary of Alberta's natural areas reserved and established. Pub. Ld. Div., Ld. Mgt. Devel. Br. Unpubl. rep., Edmonton.
-----. 1988. Boating in Alberta. Fish Wild. Div., Edmonton.
-----. 1989. Guide to sportfishing. Fish Wild. Div., Edmonton.
Alberta Native Affairs. 1986. A guide to native communities in Alberta. Native Aff. Secret., Edmonton.
Alberta Recreation and Parks. n.d. Parks Div. Unpubl. data, Edmonton.
Alberta Recreation, Parks and Wildlife. 1976. Commercial fisheries catch statistics for Alberta, 1942-1975. Fish Wild. Div., Fish. Mgt. Rep. No. 22, Edmonton.
Alberta Research Council. 1972. Geological map of Alberta. Nat. Resour. Div., Alta. Geol. Surv., Edmonton.
Beliveau, D. and A. Furnell. 1980. Phytoplankton data summary 1976-1980. Alta. Envir., Poll. Contr. Div., Water Qlty. Contr. Br. Unpubl. rep., Edmonton.
Bradley, G.M. n.d. Preliminary biological survey of six lakes in northern Alberta, 1969. Surv. Rep. No. 15. Alta. Ld. For., Fish Wild. Div., Edmonton.
Energy, Mines and Resources Canada. 1979, 1984. National topographic series 1:50 000 74D/6 (1979), 74D/3 (1984). Surv. Map. Br., Ottawa.
Environment Canada. 1975-1987. Surface water data. Prep. by Inland Waters Directorate. Water Surv. Can., Water Resour. Br., Ottawa.
-----. 1982. Canadian climate normals, Vol. 7: Bright sunshine (1951-1980). Prep. by Atm. Envir. Serv. Supply Serv. Can., Ottawa.
Finlay, J. and C. Finlay. 1987. Parks in Alberta: A guide to peaks, ponds, parklands & prairies. Hurtig Publ., Edmonton.
Geographic Board of Canada. 1928. Place-names of Alberta. Dept. Interior, Ottawa.
Gregg, A. 1976. An ecological assessment and development capability of Gregoire Lake. Prep. for Alta. Rec. Parks Wild., Parks Div. Unpubl. rep., Edmonton.
Lombard North Group. 1974. Environmental study, Amoco Canada tar sands lease, Gregoire Lake area, Alberta. Amoco Can. Petroleum Co. Ltd., Calgary.
Murray V. Jones and Associates Limited. 1978. Anzac. NE Alta. Reg. Commis., Edmonton.
Strong, W.L. and K.R. Leggat. 1981. Ecoregions of Alberta. Alta. En. Nat. Resour., Resour. Eval. Plan. Div., Edmonton.
Sullivan, M.G. 1985. Characteristics and impact of the sports fishery at Gregoire Lake during May-August 1984. Alta. En. Nat. Resour., Fish Wild. Div. Unpubl. rep., St. Paul.
Turchenek, L.W. and J.D. Lindsay. 1982. Soils inventory of the Alberta Oil Sands Environmental Research Program study area. Prep. forAlta. Envir., Res. Mgt. Div., AOSERP by Alta. Res. Counc. AOSERP Rep. 122, Edmonton.