Northern Research Basins Water Balance (Proceedings of a workshop held at Victoria, Canada, March 2004). IAHS Publ. 290, 2004, 164–177

Abstract Hydrological investigations were carried out over a 14-year period in the Canadian Shield of southeastern Manitoba (50°N 95°W) as part of the Canadian Nuclear Fuel Waste Management Program. The purpose of these investigations was to increase understanding of surface and subsurface flow and to use this information to develop defensible models of groundwater flow in granitic terrain environments. Continuous measurements were made to determine the quantities of the major water budget components: precipitation, runoff, surface and subsurface storage for the Dead Creek watershed and two catchments of southeastern Manitoba. Annual precipitation on the watershed for the study period ranged from 340 mm in 1983 to 639 mm in 1995 and averaged 526 mm. Annual basin yield varied from 2% in 1988 to 35% in 1992 and 1993, and averaged 103 mm. While the Teako Creek catchment runoff ratio (0.22) was similar to that of the Dead Creek watershed (0.20), the Wild Goose catchment runoff ratio was significantly less (0.12). This difference is believed to be due to Wild Goose catchment having less outcrop and more depression storage area, resulting in more surface water retention and higher evaporation. The annual groundwater contribution to streamflow represents only a small component, estimated at 1–2%, of the total annual basin yield. Evapotranspiration accounts for most of the annual water loss from the watershed, an average of 423 mm. This water loss causes large soil moisture deficits in overburden deposits, and complete or partial moisture restoration is dependent on spring snowmelt and early summer rainfall.

Key words Canadian Shield watershed; groundwater; snow water equivalents; soil moisture storage; water balances; winter discharge