A vector representation of stream networks is a crucial dataset for the modelling the surface water and groundwater components of the hydrologic cycle. For many usages a crucial attribute of the drainage network is a digital topology and hierarchal stream order attribute (e.g., Strahler stream order). In Canada jurisdictional stream networks are available for the provinces and territories and nationally for Canada in the National Hydrological Network (NHN) dataset. Unfortunately, the NHN data lacks the same topological and attribute information that is available for numerous provinces due to standardization for the entire country. For Canada1Water it was also necessary to have a harmonized dataset with the United States, for both the southern transboundary watersheds and the Alaskan watersheds. This report documents the processes completed to upgrade the topological and graph network support for NHN and provide continuous connectivity with US datasets. It also highlights and corrects a number of stream density and stream order issues that occur within Canada across provincial and territorial borders and NTS tiles. All vector processing was completed in RivEX software extension for ArcMap. Following complete topological correction stream classification was assigned and a table of the node graph network developed. Additional work was then completed to normalize stream density particularly amongst low-order streams between British Columbia and the Yukon and amongst local NTS tiles in Quebec and Ontario. Corrected NHN Strahler stream order assignment was validated against a number of provincial and watershed datasets, all of which already have Strahler stream order attributed. These datasets are the same underlying digitized vector data, so there are no differences in node or polyline positions. Strahler stream order assignment validation was only done by visual comparison as due to differences in vector segments a statistical comparison is complicated. The transboundary integrated C1W stream network with complete classification provides a seamless national dataset to support transdisciplinary studies (fisheries, wildlife, health, pesticide and nutrient issues, mining impact, ecosystem restoration, numeric modelling) that involve a knowledge of stream distribution and ranking.

Watershed polygons of Third Order and greater based on the Strahler Stream Order classification method and the 1:50,000 scale Canadian National Topographic Series of maps.

Points with rotations that indicate downstream flow direction. Can be displayed with arrow symbols to show flow direction. There is one point at the upstream end for each stream network feature

Six stream riparian classes ([STREAM_CLASS] = 1-6) based on presence of fish, occurrence in a community watershed and average channel width. [STREAM_CLASS] = 7 refers to unclassified streams. Stream classification is based on the 1995 Forest Practices Code Riparian Management Area Guidebook: http://www.llbc.leg.bc.ca/public/PubDocs/bcdocs/237312/Rip-toc.htm or https://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/silviculture/silvicultural-systems/silviculture-guidebooks/riparian-management-area-guidebook

This spatial layer displays stream inventory sample sites that have had full or partial surveys, and contains measurements or indicator information of the data collected at each survey site on each date.

The Single Line Hydrography Network (SLNET) contains all captured single line representations of hydrographic features. In addition, single line representations of polygonal features and single line arbitrary network connectors are in the file.

Double line streams from FC1 assigned a stream class

Flow network arcs (observed, inferred and constructed). Contains no banks, coast or watershed bourdary arcs. Directionalized and connected. Contains heirarchial key and route identifier

Stream routes. Each stream channel is represented by a single line. Derived from the Stream Centreline Network Spatial layer and based on the 1:50,000 scale Canadian National Topographic Series of Maps.

The Base Hydrography Single Line Hydrography Network (SLNET) is the Alberta Environment and Protected Areas base SLNET data set. It is an update of the Base Features HydroSLNET in Southern Alberta from orthophoto and various sources of provincial base data. It contains all captured single line representations of hydrographic features. In addition, single line representations of polygonal features and single line arbitrary network connectors are in the file.