[en] The two main factors which control the deliverability of natural gas from the Western Canada Sedimentary Basin (WCSB) are the magnitude and characteristics of the basin resources, and producer activity in resource exploration and development. This report focuses on the characteristics of the basin resources according to an assessment by the Canadian Gas Potential Committee (CGPC). The CGPC is a volunteer group of senior geoscientists from industry and government who, since 1991, have conducted independent assessments of undiscovered gas potential in Canada. Much of Canada's natural gas reserves are in non-conventional accumulations, such as in coalbed methane. This report presents a series of charts that demonstrate the magnitude of the WCSB in perspective. The WCSB represents more than 70 per cent of Canada's total conventional natural gas resources. It was estimated that the original WCSB reserve is 249 Tcf. However, only a portion of the gas-in-place can be recovered. In addition, any recovered gas must be processed before it can be marketed. At current production rates of about 6 Tcf per year, this represents a consumption rate of 5 per cent per year. It was concluded that the resource has become a major supply constraint and the likelihood of there being sufficient supply to meet the EIA demand is low. Frontier and non-conventional sources are needed to augment current producing areas. 1 ref., 11 figs