Owl River Riparian Restoration and Enhancement Project: 2021 Monitoring Report
Lindsay Dowbush, Garret McKen, and Mike Ranger
Syncrude Canada Ltd. (Syncrude) recently proposed to expand its operations at the Mildred Lake site, collectively described as the Mildred Lake Extension Project (MLX). The Owl River 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 conduct monitoring on the Owl River, focusing on: 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 2021 by ACA, on behalf of Syncrude, to address these requirements as well as integrate relevant information from previous sampling years (i.e., 2011, 2014, and 2017). 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 general, 2021 was considered a moderate to extreme drought year and hydrologically was an anomalous year for the Owl River system. Discharge was atypically low, falling below the historical lower quantile during much of the sampling period, likely impacting riparian health and overall water quality relative to other years.
Overall, riparian health conditions continually improved in 2014, 2017, and 2021 relative to the baseline assessment in 2011. We observed indications of improved riparian health from poor to fair condition, especially in areas where livestock exclusion fencing was installed in 2012. However, in 2021, riparian health in some sections had declined to conditions similar to those observed in 2014, likely due to the drought experienced across the region.
In general, water quality remained similar to 2011 baseline conditions, fluctuating slightly between years and sites, but with no strong temporal or spatial trends. In 2021, dissolved oxygen levels were within optimal ranges for walleye and the fish community, similar to previous years, but temperatures approached tolerance limits for some species in July. Total phosphorus and nitrogen concentrations were high throughout the system, similar to previous years. Similarly, total coliform counts were high and exceeded the Canadian Council of Ministers of the Environment (CCME) limit for agriculture use (>1,000 mpn/100 mL) at almost all sites throughout the monitoring period. The total number of macroinvertebrate families in 2021 was similar to those in previous years, but overall diversity was slightly higher in 2021 than in previous years. Overall water quality in the Owl River was classified as marginal in 2021, based on the CCME Water Quality Index. Due to the unusually low water levels in 2021, the fish community and aquatic habitat assessments were deferred to 2022 and are not included in this report.
In July of 2021, a landowner with two quarter sections of private land on the Owl River expressed interest in participating in the Owl River riparian project. ACA signed a formal conservation lease agreement with the landowner, resulting in 3,444 m of fence (wildlife-friendly wire and rail fencing, and wooden signposts) being installed within the two quarter sections in October of 2021, protecting 25.30 ha of riparian habitat. Seven additional landowners and one additional leaseholder of the eleven selected in the Owl River focus area have been contacted, and lease and/or habitat purchase negotiations are continuing in hopes to add more riparian protection in 2022.