The Impervious Surface - 1995 layer contains polygon features generated from the 1995 through 1998 Digital Aerial Survey mapping line work. The use of multiple years of DAS updates best reflects the impervious layer as it was in 1995.The Impervious Surface layer features represent the various impervious surface types found within The City of Calgary. These features are classified by surface type and description based on the classifications and specifications used in the Digital Aerial Survey Program. Additional higher level general surface type classification and referencing to the Alberta Township System (ATS) has been applied to each impervious surface layer feature. To learn more about other DAS products available, visit Digital Aerial Survey.

The Impervious Surface 2021 dataset is a collection of polygon features derived from Calgary Digital Aerial Survey mapping linework which have been determined as impervious. Impervious surfaces are defined as any material which will seal the soil surface, impede water infiltration, collect solar heat or deprive tree or vegetation roots of aeration. Impervious surfaces effect many aspects of our City, including storm run off volumes, pollutant concentrations and drainage. The City must understand and manage the amount of impervious surfaces carefully to ensure the ongoing health and vitality of the municipality and the environment. To learn more about other DAS products available, visit Digital Aerial Survey

The impervious surface layer for 2016 contains polygon features generated from Digital Aerial Survey mapping line work. The layer features represent the various impervious surface types found within The City of Calgary. These features are classified by surface type and description based on the classification and specifications used in the Digital Aerial Survey Program. Additional higher level general surface type classification has been applied to each impervious surface layer feature. To learn more about other DAS products available, visit Digital Aerial Survey.

The Impervious Surface - 2010 layer contains polygon features generated from the 2010 Digital Aerial Survey mapping line work. The Impervious Surface layer features represent the various impervious surface types found within The City of Calgary. These features are classified by surface type and description based on the classification and specifications used in the Digital Aerial Survey Program. Additional higher level general surface type classification and referencing to the Alberta Township System (ATS) has been applied to each impervious surface layer feature. To learn more about other DAS products available, visit Digital Aerial Survey.