Earth Sciences Report 1971-01

Earth Sciences Report 1971-01

ESR 1971-01

Hydrogeology of the Red Deer Area, Alberta

Author(s) Le Breton, E.G. Date 1971-01-01

The 5,800 square miles covered by the Alberta Hydrogeological Reconnaissance Map of the Red Deer area is divisible into two main topographical regions, one dominated by northwest-trending ridges (with local relief of 100 to 300 feet) to the west and the other characterized by flat to gently rolling land to the east. The area is traversed by the Red Deer and the Battle Rivers.

According to Koeppen's classification, the climate of the area is humid continental, having a cool summer and no dry season. Most wells in the Red Deer area are completed in the near-surface bedrock strata composed of the bentonitic siltstones and local to extensive medium- to coarse-grained, friable, calcareous and bentonitic sandstone beds of the Paskapoo Formation, and the bentonitic siltstones and thin bedded sandstones, coal and carbonaceous shales of the Edmonton Formation. Surficial deposits, apart from sand and gravel deposits in preglacial valleys, are not an important source for groundwater in the Red Deer area.

Anticipated groundwater yields range from over 500 imperial gallons per minute (igpm) to less than 1 igpm in the eastern part of the region, thus limiting development of groundwater supplies here for use as rural domestic, livestock and perhaps municipal supplies.

High ground in the west generates groundwater flow systems of local to regional scale, discharge being evidenced by springs, salt deposits and flowing wells. Low local relief in the east of the map area and the limited groundwater discharge features indicate the poor groundwater resources, and the sluggish groundwater flow systems.

The chemical facies of near-surface groundwaters are predominantly sodium bicarbonate and sodium sulfate, the sulfate-type of groundwater being of secondary importance. Total dissolved solids are generally less than 1000ppm in the western portion of the area, increasing eastwards to over 2000ppm in the southeast corner. Changes in water chemistry with increasing depth are less pronounced in the western part of the area than in the east, as shown in the hydrogeological profiles.

Hydrogeological profiles portray also the 'active zone' of groundwater in the Red Deer area to be up to 500 feet in the western portion of the area, where the groundwater flow is strongly influenced by the greater local relief, thinning to less than 300 feet in the eastern part of the area where local relief and bedrock materials are generally finer grained. Correspondingly, the quality of groundwater for drinking purposes is suitable to depths of 1000 feet in the west part of the Red Deer area, decreasing to only 300 feet in the east part.

Le Breton, E.G. (1971): Hydrogeology of the Red Deer area, Alberta; Research Council of Alberta, RCA/AGS Earth Sciences Report 1971-01, 17 p.