New bi-national assessment charts path to reduced pollution in the Rock River watershed

A watershed scientist collects cross-section data in the Rock River watershed, part of the field effort involved in evaluating river condition and identifying phosphorus reduction opportunities. Photo: Fitzgerald Environmental Associates

A recently completed assessment of the bi-national Rock River identified opportunities to reduce phosphorus and is the first of its kind in the Lake Champlain Basin. Using consistent tools and methods on both sides of the United States-Canada border, environmental consultants working with the Lake Champlain Basin Program (LCBP) identified 15 high-priority restoration projects on the Rock River in Vermont and Québec.

The LCBP played a unique role in the project, bringing partners from different jurisdictions together to improve water quality. The effort to harmonize scientific techniques and management solutions is charting a coordinated path to improved watershed health in an area where restoration work has historically been difficult.

In addition to managing historical differences in assessment methods and management approaches, the logistics of cross-border work during the Covid-19 pandemic were a challenge. The project is a major success and sets an exciting precedent for future cross-border collaboration.

A Unique Opportunity for Cross-Border Collaboration

In 2017, the Lake Champlain Steering Committee identified the Rock River watershed as a priority area for structural evaluation and restoration and invested in a novel cross-boundary approach to prioritizing restoration. Spanning parts of Vermont and Québec, the watershed is made up primarily of farms and forests. The river is a target for restoration to reduce phosphorus loading to Lake Champlain’s Missisquoi Bay.

Nearly two decades ago, the Vermont portion of the Rock River watershed was evaluated using a Stream Geomorphic Assessment (SGA), a comprehensive survey process developed by the Vermont Agency of Natural Resources. Evaluations using similar methods have taken place in portions of the watershed in Québec. Until the most recent assessment, however, the entire Rock River watershed had not yet been evaluated within a consistent framework that could provide meaningful management insights to both Vermont and Québec.

Before work on the project began, the Vermont Department of Environmental Conservation and Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks) collaboratively developed a common set of methods and goals for the project. The LCBP was uniquely positioned to support this collaboration, which ensured project outcomes would be valuable and relevant on both sides of the border.

The Rock River: Challenges & Opportunities

The Rock River (French: Rivière de la Roche)originates in the towns of Highgate and Franklin in Vermont’s Franklin County. The river travels west and north, crossing the border into Québec where it receives water from several tributaries. The river then winds south, re-entering Vermont and draining into the Missisquoi Bay less than two miles from the border.

Encompassing a rural region of northern Vermont and southern Québec, the landscape of the Rock River watershed is flat and sparsely developed. Vast farm fields and patches of forest dot the landscape, with most of the agricultural land flanking waterways and their floodplains.

While some sections of the Rock River and its tributaries are stable, other areas are vulnerable to erosion and flooding. Stretches of river that have been ditched or extensively straightened—a process that removes a stream’s natural bends—are particularly susceptible.

The Rock River feeds into Missisquoi Bay, which also receives water from the Missisquoi and Pike Rivers. While this shallow bay contains less than one percent of Lake Champlain’s total volume, it represents seven percent of the lake’s surface area and is a popular site for recreation. Unfortunately, higher-than-average nutrient concentrations and seasonal release of legacy phosphorus, stored in lake sediments, contribute to frequent cyanobacteria blooms throughout the summer months, limiting opportunities for recreation and other activities.

Understanding River Systems Using Stream Geomorphic Assessments

Human activity can disrupt a river’s equilibrium, or the balance of how it moves water and material. Ditches and channels, river straightening, and the addition of infrastructure like culverts all change a river’s flow dynamics and can negatively impact water quality and ecosystem function.

SGAs are used to evaluate the condition of a river system and improve understanding of its characteristics, vulnerabilities, and potential needs for targeted restoration. These assessments help to identify priority projects that can restore river equilibrium. Project outcomes typically include improved water quality, habitat connectivity, and resilience to extreme weather.

The Rock River SGA included two distinct phases of data collection. The first used a specialized mapping tool developed by the Vermont River Management Program that gathered and incorporated watershed-scale data into an existing database to identify preliminary priority areas. The research team also conducted a broad “windshield” field survey to verify topographical features and identify human-made infrastructure like culverts. The second phase included additional surveys of prioritized river segments in Québec, as well as a resurvey of the Vermont regions studied in 2007 with updates to the methods and reporting.

Navigating Cross-Border Work During Covid-19

LCBP selected Fitzgerald Environmental Associates (FEA) to assess the Rock River on both sides of the US-Canada border—a significant undertaking under normal circumstances, made more complicated by the onset of the Covid-19 pandemic in 2020.

Joe Bartlett is a Senior Watershed Scientist at FEA and played a key role in the Rock River assessment. From the project’s inception in 2019, before the pandemic, his team faced cascading challenges. The first phase of study involved collection and integration of watershed-scale data from the Québec portion of the Rock River, a seemingly straightforward task that was complicated by an outdated database requiring laborious manual data entry.

Simultaneously, poor weather in November of 2019 hampered efforts to begin fieldwork in Québec. The team decided to postpone the field component to the summer of 2020, yet over the course of the following spring it became clear that the fieldwork would have to be pushed back—again.

In late summer of 2021 the FEA team began field work in Québec, just two days after border restrictions were lightened. At that time, negative Covid test results from within the prior 72 hours were required to enter Canada from the United States. With ten total field days on the docket, Bartlett and his team became regulars at their local Covid testing location, at times waiting morning-of for a negative result needed to complete planned work in Québec that same afternoon.

“An incredible amount of logistics coordination went into our field work in Québec, from timing Covid testing to using GPS tracking to make sure we didn’t unintentionally cross the border while surveying in remote areas,” Bartlett shared with the LCBP. Adding to the complexities were the drought conditions under which the team was working. Such low flow conditions “require a completely different frame of reference—especially in the consideration of floodplain reconnection, which was one focus of our survey efforts,” Bartlett said.

Next Steps: Maximizing Impact through Partnership

Of 69 possible restoration projects identified within the Rock River watershed, FEA selected 15 high-priority projects in partnership with Friends of Northern Lake Champlain and Organisme de basin versant de la baie Missisquoi (Missisquoi Bay Watershed Organization). Of those 15, nine projects selected are located in Québec and six are in Vermont.

While each project seeks to improve water quality, river stability, and aquatic habitat, the specific problems—and their solutions—vary. Québec-based projects include enhancing an accessible floodplain with tree and shrub planting; adding stormwater infrastructure to both sides of the Highgate Springs/Saint Armand border crossing; and stabilizing a farm ditch that contributes excess sediment and nutrients to Brandy Brook. In Vermont, an undersized culvert has been selected for replacement; an eroding agricultural channel needs a buffer planted; and a disconnected forested floodplain can be restored.

International watershed restoration presents unique challenges and opportunities to regional stakeholders. While management often falls to individual jurisdictions and associated organizations, the Rock River is one example of a waterway that crosses borders. River-related problems in Vermont may have downstream impacts in Québec, which then manifest in further challenges in Lake Champlain, a body of water shared by both the U.S. and Canada.

“This was a great project for the LCBP to be involved in as a coordinating partner,” Bartlett shared. By drawing on the resources and expertise of organizations on both sides of the border, the LCBP and partners have together identified the highest-impact projects that will benefit water quality and habitat connectivity within the Rock River watershed, and more broadly in Lake Champlain’s Missisquoi Bay and beyond. The project sets an exciting precedent for future collaboration in support of a healthier Lake Champlain Basin.

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