Owl River Riparian Restoration and Enhancement Project: 2025 Monitoring
Interim Report
Author(s)
Garret McKen, B.Sc., P.Biol.
Lindsay Marley, B.Sc., P.Biol.
Emily Franks, B.Sc., M.Sc.
Lance Engley, B.Sc., P.Biol.
Summary
Syncrude Canada Ltd. (Syncrude) has proposed to expand its operations at the Mildred Lake site, collectively described as the Mildred Lake Extension Project (MLX). The Owl River Riparian Restoration and Enhancement Project, described herein, is one of two Department of Fisheries and Oceans (DFO) authorized offsets for the MLX project. This MLX offset builds on related habitat offset and restoration activities already conducted on the Owl River by Alberta Conservation Association (ACA) on behalf of Syncrude from 2011–2017 for the Base Mine Lake project.
To satisfy requirements of the DFO authorization, Syncrude is required to monitor several features of the Owl River: i) riparian habitat; ii) water quality and instream habitat; iii) macroinvertebrates; and iv) resident and migratory fish. In this report, we present results from surveys conducted in 2025 by ACA, on behalf of Syncrude, to address these requirements as well as integrate relevant information from previous sampling years (i.e., 2017 and 2021). Our study area extended 46 km upstream from the mouth of the Owl River at Lac La Biche and included portions of two tributary streams of the Piche River and Square Creek.
In 2025, the study area experienced drought conditions ranging from a five- to ten-year drought (moderate) in May and June to a 20- to 25-year drought (extreme) in July and August. Water discharge fell well below the historical lower quartile during much of the sampling period, likely impacting riparian health and overall water quality.
To help improve riparian health, ACA approached landholders along the Owl River about participating in restoration and enhancement projects. As of 2025, all landholders in the Owl River riparian study area that were interested in participating have entered into 25-year agreements. Five formal Riparian Conservation Agreements (RCAs) have been signed with three landholders, resulting in 144.63 ha of riparian habitat and 11.74 km of shoreline being protected.
Of the 46 km study area, we assessed the first 33 km upstream from Lac La Biche for riparian health. This stretch of the Owl River is largely characterized by private and Crown grazing land, with the final kilometre on undisturbed Crown land being used as a reference. We did not assess the remaining 13 km of the study area, also located on undisturbed Crown land, as the riparian assessments focused on areas associated with private land stewardship and RCAs. However, water quality and macroinvertebrate sampling were conducted at sites within this 13 km section. The 33-km riparian assessment area was divided into 67 reaches, each 500 m in length. The riparian habitat of these reaches was assessed using the Riparian Quality Index (RQI) methodology.
Despite drought conditions in 2025, riparian health continued to improve. Compared with the baseline assessment in 2021, the 2025 RQI assessment showed that multiple reaches shifted from a Moderate to Good health status category, with Habitat Unit Equivalents per square metre (HUe/m²) ranging from 4.01 (Moderate) to 7.49 (Very Good). This represented a gain of 583,220 HUe (7.3%) within the 144.63 ha encompassed by RCAs. Within the RCAs, a total of 8,522,584 HUe was realized based on 2025 RQI scores. This value represents 51% of the Phase 2 target of 16,842,000 HUe, which corresponds to the maximum potential riparian functional value at 8.02 HUe/m2.
Water quality remained similar to conditions seen in previous years, fluctuating slightly between sites, but with no strong spatial trends, except for turbidity that increased downstream on the Owl River. Based on the Canadian Council of Ministers of the Environment Water Quality Index, overall water quality in the Owl River was classified as Marginal in 2025, similar to 2021. Monthly pH and conductivity were comparable among sites, dissolved oxygen was high throughout the system, and average daily temperatures during summer months remained mostly within tolerable limits for most fish species, similar to 2021. Total phosphorus and nitrogen concentrations remain high throughout the system as in previous years. Likewise, high levels of the fecal coliform, Escherichia coli (E. coli) throughout the system indicate fecal contamination similar to previous years.
The total number of macroinvertebrate families in 2025 was slightly lower than in 2021, but overall macroinvertebrate abundance, richness and %EPT (Ephemeroptera, Plecoptera, and Tricoptera) were higher in 2025 than in 2021. Due to the unusually low water levels in 2025, the fish community and aquatic habitat assessment were deferred to 2026 and are not included in this report.
The Owl River has experienced large swings in weather patterns in recent years—from extremely high precipitation and resulting water levels in 2017 to the extreme drought conditions and low water levels observed in 2025. These fluctuations highlight the importance of protecting sensitive habitats such as riparian areas. Significant changes to water quality have not yet been observed; though improvements to water quality and instream habitat are not necessarily expected to occur in the early phases of the project. These potential improvements are also influenced by background (i.e., environmental and upstream) conditions in the Owl River system. The riparian health improvements in 2025 are likely linked to the strong stewardship ethic of landholders along the river. Many recognize the connection between healthy riparian habitat and long-term agricultural and ecological sustainability. Their willingness to collaborate with ACA through the implementation of RCAs has been fundamental to improving riparian health without negatively impacting their operations. We will continue to monitor riparian conditions and water quality every three years and work with landholders to maintain and enhance riparian habitat on the Owl River.