| Abstract/Description or Keywords |
Surface water resources include existing watercourses, lakes and other natural surface water bodies encountered or approached by the project right-of-way (RoW). Surface water resources are discussed in the context of hydrology and surface water quality. This technical data report (TDR) addresses hydrology. Water quality is presented in the Surface Water and Sediment Quality Technical Data Report (Touchinski et al. 2010). This TDR describes the baseline characteristics of the biophysical elements assessed in the environmental and socio-economic assessment (ESA) for the Enbridge Northern Gateway Project (Project). This information will be used to identify construction and operational mitigation measures needed to reduce or avoid environmental effects on biophysical elements. It will also be used as a basis against which environmental effects on hydrology will be assessed. Surface water hydrology is the movement of water over land, into and through surface water bodies such as wetlands, lakes and watercourses. Hydrology involves the interactions between precipitation, surface storage, evaporation, evapotranspiration, infiltration, surface runoff and groundwater. Surface runoff is the primary mechanism for transporting sediment from land into watercourses and surface water bodies. Surface water hydrology is directly linked with other aquatic resources, such as fisheries and water quality, as well as groundwater systems. The hydrology baseline for the Project was prepared using information generated from existing literature sources and field surveys for the following key data categories: • mean seasonal and mean annual total flow volumes • 1:10 and 1:100 year return period peak flows • drought (low) flows • freeze-up and breakup timing and average duration of ice cover • climate data (specifically rainfall) • channel dimensions (width, depth and gradient) • channel bed and bank materials. The geomorphology of a channel is a function of streamflow, sediment load, surficial geology and channel geometry (principally width, depth and gradient). The process of bed and bank erosion, sediment transport and sediment deposition are in balance in a stable channel for the local streamflow and sediment supply regimes. Changes to any of the three basic variables of streamflow, sediment load or channel geometry can affect the geomorphology of the watercourse. In addition to the hydrological parameters listed above, the hydrology baseline summarizes data gathered during the hydrology and fisheries field studies on channel geometric properties. Baseline sediment data are presented in the water quality baseline report. |
