IMPACTS OF URBANIZATION ON THE WAGNER NATURAL AREA, EDMONTON, ALBERTA

The Wagner Natural Area (WNA) is a 260 hectare conservation area on the outskirts of the City of Edmonton, Alberta. It is renowned for its mineral-rich fen(s) made up of wet meadows, marl ponds, black spruce, and tamarack forest. For such a small area the overall biodiversity in the WNA is unusual, and the WNA owes its diverse array of flora and fauna to groundwater-fed calcareous springs that flow year-round and precipitate marl. Long-term stability of the natural groundwater flow regime in the vicinity of the WNA is crucial for the protection of this unique ecosystem.

Unfortunately the groundwater flow system around the WNA is under increasing pressure due to urbanization. The WNA faces multiple threats: 1) industrial developments in the recharge area that reduce groundwater infiltration and increase surface water flows offsite; 2) industrial developments that could impact water quality in the natural area; 3) nearby residential developments utilizing groundwater wells and septic systems; and 4) developments in the discharge area e.g., ditching, drainage, etc. lowering water levels.

To better understand the groundwater flow system supplying the WNA we have conducted multiple hydrogeological studies, including: drilling programs; continuous water-level monitoring; electrical resistivity surveys; vegetation mapping; and numerical modeling. A three-dimensional numerical model of the groundwater flow system around the WNA delineated the recharge area and showed the flow system is sensitive to alterations to recharge and surface drainage.

Hydrogeological results are being incorporated into land use planning to protect the long-term integrity of the Wagner Natural Area groundwater flow system.