Working Towards an Environmental Water Needs Assessment and Monitoring Framework for a Cold Regions Deltaic Ecosystem

Abstract:

The Peace-Athabasca Delta (PAD) is a 6000 km² lake/wetland ecosystem at the confluence of the Peace-Athabasca-Birch rivers with Lake Athabasca, northwestern Canada. This low relief, deltaic floodplain contains more than 1000 wetland basins with varying degrees of connectivity to the main flow system. Hydroperiod is influenced by occasional ice-jam and open-water inundations that recharge wetland basins. The biologically rich delta is a Ramsar Convention wetland site of international importance, and is located within the Wood Buffalo National Park (WBNP) listed as a UNESCO World Heritage Site.

The PAD ecosystem is influenced by local and upstream pressures from flow regulation (eg, hydroelectric dams), water and land use (eg, oil sands mining) and climate change. Growing concern regarding increased cumulative effects on the delta led Indigenous Peoples petitioning UNESCO World Heritage Committee (WNC) to reassess the protection status of the park. The WBNP Action Plan was developed to address 17 UNESCO WHC recommendations to ensure maintenance of Outstanding Universal Value of the Park. One key set of recommendations is to: i) Conduct environmental flows assessments, to the highest international standard, in order to identify water flows needed to sustain the ecological functioning of the PAD under current and projected development and climate change; ii) Establish adequate baseline hydrological information for PAD assessments.

A significant scientific effort has been invested in the last four decades in improving our understanding the relationship between streamflow, geomorphology and aquatic ecology. However, a key question is whether riverine focused environmental flow methods are applicable to deltaic environments influenced by cold region processes? The goal of this presentation is twofold: i) Assess the potential applicability of riverine environmental flow frameworks to deltaic floodplain environments where small changes in water level/depth have important implications for surface water connectivity and associated habitat quality, and ii) Explore the development of an eco-hydrological framework and tools necessary to assess changes to the aquatic ecology within the PAD, such as novel ground-based DNA and satellite-based metrics of change, plus LiDAR based 2-D hydraulic models.