Paleolimnological studies to distinguish the roles of river regulation and climate change on persistent low water levels in the Peace-Athabasca Delta

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For over 50 years, concerns about the potential linkage between upstream river regulation by the WAC Bennett Dam (in BC) and observed low water levels in the world-renowned Peace-Athabasca Delta (PAD; in AB) have been a perpetual narrative. Recently, this issue has gained additional traction with the 2014 petition by the Mikisew Cree First Nation to have Wood Buffalo National Park, which includes the PAD, designated on the List of World Heritage in Danger and the subsequent 2017 UNESCO Reactive Monitoring Mission Report. To address these concerns, co-PIs Hall and Wolfe led paleolimnological studies during the early 2000s designed to provide critically missing spatial and temporal perspectives beyond the brief hydrometric records at a few sites on the Peace River. Results identified that climate and other factors, not river regulation, are the prevailing drivers of hydrological change in the PAD. Despite recognition and acceptance of these important findings among the international scientific community via peer-reviewed publications, they remain untenable among some scientists, stakeholders and decision makers. Here, we propose six projects to advance and strengthen the paleolimnological knowledge of the PAD, and to address remaining knowledge gaps concerning the roles of river regulation versus climate change on lakes in the PAD. We will analyze sediment cores from: 1) previously studied lakes to add 17 years of record (34% extension) to the post-dam paleohydrological reconstructions, 2) lakes of local interest to increase relevance to local First Nation residents and Park Managers, 3) lakes near Rocky Point to capture river regulation hydrograph effects, 4) lakes outside the PAD for local climate reference, 5) lakes in the unexplored northwest Peace sector to increase spatial coverage across the delta and 6) lakes on the Smoky and Wabasca river floodplains to assess timing of hydrological changes in these 'trigger tributaries'. Methods employed will include those proven to be effective based on our prior studies. Results will provide knowledge to inform our industrial partner, BC Hydro, and national Working Groups tasked with ensuring environmental flows are maintained for the PAD.********