Low Water Levels in the Mackenzie River

The Mackenzie River (Deh Cho) is the pre-eminent waterway of the western arctic and subarctic, providing a tremendous number of ecosystem services for species that are adapted to life in or near the river and serving as a vital sustenance source, and transportation and commercial link for communities along and adjacent to the Mackenzie valley. I have a long personal history with the river, having worked as a recreational fishing guide on it near Great Slave Lake in the early 2000’s, and later shaped my career trajectory working in the Sahtu and Mackenzie Delta regions on, and adjacent to, it. On trip through Norman Wells in August 2025, I observed that late-summer water levels appeared to be very low – significantly lower than I recalled from previous time spent along this stretch of river. I spoke with several local residents and commercial barge staff who confirmed that water levels were, indeed, lower than typical and that this was affecting both traditional travel routes and commercial marine operations and was part of a larger, emerging, pattern of low summer water levels. I recalled seeing exposed mudflats in early fall while working in the region in 2017-2020. These same areas, in 2025, were not only exposed, but infilled with sedge species and horsetail, suggesting that, while still routinely inundated, they are transitioning from riverbed to riparian areas.

Causes Climate models have predicted increasing flow volumes from arctic rivers as the arctic rapidly warms (Patro et. Al, 2024). At first glance, my observation appears to be at odds with modelled predictions. However, much of the increased flow volumes are occurring in winter – a period in which northern rivers, both the Mackenzie itself and tributaries, are typically at their lowest flow rates (Rosenburg et al., 1986; Woo & Thorne, 2003). Additionally, the western subarctic has had a period of several back-to-back summer droughts (Canadian Press, 2024), consistent with observations of arctic warming occurring ahead of modelled predictions (Balting et al., 2021). It is probably that the lower flow rates in summer are a combination of increased discharge of snowfall and meltwater during cold periods and lowered influx of summer rains due to prolonged drought conditions.

Effects and Connections Because a road network is largely absent in the Mackenzie Valley, save for connections near the various headwaters and at Inuvik in the Mackenzie Delta, and because air transport is often prohibitively expensive, river traffic (by ice road in winter and boat in summer) is the primary means of transport in the region. Traditional land uses require river travel to hunting and gathering areas, as well as utilization of river fisheries. Commercial and non-traditional sustenance requires barge travel by means of a dredged channel extending from Hay River into the Beaufort Sea. The shallowing of the river in summer creates localized barriers (as observed in the aforementioned emerging riparian areas) that can force rerouting of traditional travel routes and block commercial transport entirely, thereby isolating river communities, (Canadian Press, 2024). Resilience of ecosystems and communities depends on both localized and external factors (Holling, 1986) and the creation of barriers along one section of the river forces changes to other ecologies and communities throughout the system. These barriers create a unique challenge in Norman Wells, as the community has prioritized oil extraction over traditional lifestyles for several decades – a practice that both relies on the river for logistics and that has contributed to the observed shallowing effects. Hyperfocus on one aspect of a local ecosystem or socio-economic element of a community can result in a narrowing of place and identity (Dale, 2008) and the focus on resource development has created such a narrowing at Norman Wells. As such, some traditional knowledge of place may have been lost and, with that loss, traditional forms of utilization have become more rigid and less resilient. River ecology, subsistence use, and commercial use all function as an integrated panarchy. A loss of adaptability and rapid change in ecology, or a loss of community-river understanding at the local level likely results in increased reliance on commercial transport for community stability, which, in turn becomes more rigid itself as local adaptation to barriers ceases to filter upward and more resources are required to maintain systems and networks.

AI Comment from GPT 5:

Recent posts across the Mackenzie system describe a similar pattern of very low water, hazardous travel, and supply disruptions, with some context on potential drivers and short-term variability:

• Low water makes fall travel on the Mackenzie River hazardous for hunters (Łı́ı́dlı̨ı̨ Kų́ę́/Fort Simpson): Reports record-low stages since 1938, with unpredictable channels and sandbars forcing many to switch from river to land travel. According to a territorial hydrologist cited in the post, low levels are driven primarily by climate change, compounded by a shifting El Niño and upstream flow changes from dams in northern B.C.; filling of the Site C reservoir reportedly lowered Great Slave Lake by about 8 cm. Local leaders also highlight concerns about drought, hydro development, and potential releases of treated oilsands tailings.

• Norman Wells and Tulita, N.W.T., won't get barge deliveries this year: Confirms direct logistical impacts in the same reach as the observation, with barge cancellations due to low water.

• Low water in N.W.T. means cargo heading to northern communities via Tuk, not Hay River: Describes rerouting of marine cargo via the Arctic Ocean when Mackenzie River stages are too shallow, echoing the commercial challenges noted in the observation.

• As Fort Simpson, N.W.T., ferry crossing opens for the season, low water levels worry mayor and Fort Simpson mayor says water levels might end ferry season early this year: Highlight concerns that low water can curtail ferry operations and isolate communities—consistent with the observation’s note that shallower channels create barriers to traditional and commercial travel.

• Glaciers melting quicker as N.W.T. copes with record low waters: Summarizes research linking wildfire ash to faster glacier melt and reduced inflows to the Slave River watershed, with Great Slave and Great Bear Lakes at historic lows and barge routes disrupted. Territorial officials quoted in the post suggest near-term precipitation could offset some losses but warn of long-term shifts in river flow patterns—consistent with the observation’s discussion of changing seasonality of flows.

• Water levels starting to rise in some parts of N.W.T., but still very low: Notes modest rebounds in places like the Beaufort Delta while most major rivers and lakes remain well below normal; a full recovery may take years amid extreme variability. This aligns with the observation’s account of persistent late-summer low stages and emerging riparian vegetation on former riverbed.

• N.W.T. communities prepare for spring floods, as high water levels persist: Documents the opposite phase earlier in the decade—record-high levels in 2020 and flood risk in 2021—showing how quickly the system can swing between very high and very low water.

• This pink salmon swam farther up the Mackenzie River than ever recorded: Records a northward/upstream shift in salmon distribution, an ecological signal of broader change in the basin that complements the observation’s notes on habitat transitions (e.g., mudflats infilling with sedge and horsetail).

Taken together, these posts depict a basin-wide pattern of unusually low summer and fall water in recent years, with travel hazards, supply-chain disruptions, and signs of ecological change. They also point to interacting drivers and shifting seasonality—climate change, El Niño, watershed management, and variable precipitation—reported by hydrologists and officials in the linked posts.