Acquired aerial photography (1:5000 to 1:60 000 scale).
Performed aerotriangulation of photography, geo-referencing all photogrammetric controls to true ground coordinates.
Collected vector digital data using analogue plotters (Wild A10 - A8 - B8S). Vector data were three dimensional (x,y,z) and geo-referenced to UTM coordinates. The output format was DXF.
Performed cursory checks of digital data (removal of pseudo nodes, creation of polygons, etc.).
Built lines and points then copied attribute information from the ACODE and XCODE tables into the arc and point attribute tables (AAT and PAT). Dropped five attribute fields from the resulting attribute tables.
Selected arcs representing water lines based on the dxf-layer attribute. Put the arcs for each category to respective ArcInfo coverages. Visually checked and edited dangles to ensure that they snapped to water polygons. Checked each coverage for double line streams/rivers. If double lines existed, removed the arcs and put them into the water polygon layer. Joined all water line layers into one coverage and cleaned with tolerances of 0.01.
Appended mapsheet water line coverages into a Manitoba-wide coverage and cleaned with fuzzy and dangle tolerances of 0.01. Unsplit arcs based on the dxf-layer attribute code. Performed edits to ensure good edgematching.
Added arcs from 1:20 000 other line and drain coverages to correct for missing sections in some streams, rivers, and drains. Cleaned the resulting water line coverage with tolerances of 0.0001.
Named rivers, streams, and drains by referring to 1:50 000 paper maps and 1:20 000 drain coverages.
Classified water lines into three categories: Major, Medium, and Small. Major water lines included rivers and drains that overlapped with a 1:1 000 000-scale hydrography layer. Medium water lines included perennial rivers, dykes, and tributaries of major rivers. Small water lines included tributaries of medium rivers and ditches, linear depressions, indefinite and intermittent rivers, canals, dams, culverts and rapids.