Classification of Transboundary Groundwater. Hydrogeological information to delineate Transboundary Groundwater in the YT-BC border region is scarce and most of the aquifers in this area are not defined and mapped; thus, watershed boundaries were used as a surrogate for delineating Transboundary Groundwater at the sub-basin level. These surrogates are referred to as groundwater areas, which will be used until more information is available and aquifers are mapped. Groundwater areas provide an area based framework for data collection and synthesis and identification of key information gaps. It was assumed that topographic slope reflects shallow Groundwater flow directions and that surface sub-basins generally reflect Groundwater flow patterns within the smaller discrete sub-watershed units in order to facilitate management and investigations of Groundwater. The Liard sub-basin 2, 3 & 4, Teslin sub-basin 1 & 2 and Alsek sub basin 1 & 2 were defined as groundwater areas relevant to this agreement and were classified based on Groundwater areas (Figure 2). Based on current available information all of the seven Transboundary Groundwater areas were classified as class 1 for both quantity and quality.
Classification of Transboundary Groundwater. Hydrogeological information to delineate Transboundary Groundwater in the NWT-YT border region is scarce and most of the aquifers in this area are not defined or mapped. As an interim approach, surface watershed boundaries for the NWT-YT Liard sub-Basin Transboundary Waters listed in Table 2 are to be used as a surrogate for delineating Transboundary Groundwater. This surrogate is referred to as a groundwater area (Figure 23, which will be used until more information is available and aquifers are mapped. Groundwater areas provide an area-based framework for data collection and synthesis and identification of key information gaps. It was assumed that topographic slope reflects shallow Groundwater flow directions and that surface sub-basins generally reflect Groundwater flow patterns within the smaller discrete sub-watershed units in order to facilitate management and investigations of Groundwater. However, it is presumed and acknowledged that the aquifers and/or aquifer systems underlying the NWT-YT Liard sub-Basin Transboundary Waters extend beyond the surrogate groundwater area. Therefore, because of the proximity of the Liard sub-Basin groundwater areas in the BC- NWT and BC-YT Agreements, information on these groundwater areas will be shared between the NWT and YT for the BMC to consider: a) if the extent of the NWT-YT groundwater area should be revised; and/or b) if the RIM class of the NWT-YT groundwater area (Table 9) should be revised. Currently, the groundwater area is classified as class 1 based on Groundwater quality and quantity. ATTACHMENT B
Classification of Transboundary Groundwater. Areas for Water Quality and Quantity
