This Story Map is a product of the Nooksack FLIP Steering Committee and supporting contributors. The information contained herein should not be construed as representing policy positions of the entities for which the individual Steering Committee members work.
Source: Furness and Schillinger-Brokaw (2023), Learning from the Past: Governing Transboundary Nooksack River Flooding (Jefferies and Hager, 2023). Border Policy Research Institute Publications. 133. https://cedar.wwu.edu/bpri_publications/133
Introduction
The dynamic Nooksack River periodically floods a broad landscape affecting residents, commerce, a variety of farmers and their employees, utility providers, critical infrastructure, fish and wildlife and their habitats, and recreational users of the river.
November 2021 Flooding around the City of Everson Source: Northwest Hydraulic Consultants
Severe flooding in November 2021 brought those impacts into stark focus. Floodwaters inundated communities along the river, including Ferndale, Lummi Reservation, and Marietta. Further upstream, Nooksack floodwaters overtopped the river's banks near Everson and spread north, passing through the small cities of Everson, Nooksack, and Sumas. Floodwaters also crossed the border into Abbotsford, British Columbia.
The disruption of normal life for those communities was widespread due to flooded buildings, inundated roads and highways, damage to farms, and isolation and closure of critical businesses, facilities, and infrastructure. Damages totaled over a billion dollars and as of early 2024, some residents have still not been able to return to their homes.
The November 2021 floods also provided an indication of what could occur in future floods, lending urgency to the need to implement multi-benefit solutions that protect and strengthen floodplain communities.
Map Showing Extent of the November 2021 Flood
The Nooksack Transboundary Flood Initiative was formed shortly after the flood. This is a nine-party agreement to collaborate on actions for flood risk reduction and habitat restoration in the flood-prone Nooksack River and Sumas River watersheds. It was signed by the Governor of Washington State, the Premier of British Columbia, and representatives from Whatcom County, the City of Abbotsford, Lummi Nation, the Nooksack Indian Tribe, Sumas First Nation, Matsqui First Nation, and Leq’á:mel First Nation.
Field tour of farmland flooding in February 2020 Source: Whatcom County
Whatcom County is simultaneously leading a floodplain management planning process, referred to as Floodplain Integrated Planning (FLIP). The FLIP process is focusing on the 36-mile length of the Nooksack River from Deming to Bellingham and Lummi bays in Puget Sound - called the Lower Nooksack River – as well as the “flow split” corridor extending from Everson north through the Sumas River valley to the Canadian border at Abbotsford.
The FLIP process aims to develop long-lasting solutions that reduce flood risks to cities, farms, and critical public infrastructure, while also improving fish habitat. It includes continuous collaboration with representatives of tribes, cities, the agricultural community, state and federal agencies, and local universities.
Flooding between Everson and Sumas in November 2021 due to Nooksack River overflow Source: Northwest Hydraulic Consultants
To the extent possible, the FLIP work includes floodplain areas along the South, Middle, and North forks of the river, but its primary focus is the many issues to resolve along the Lower Nooksack River, downstream of Deming.
Flooding in the Nooksack River cannot be stopped, but together we can create a future landscape surrounding the river that is better able to withstand those floods, with thriving fisheries, farms, and cities. The best way to create that future is to work together, rooted in shared values. Whatcom County and its partners in this vitally important work invite your input through the FLIP Online Comment Form linked below.
Floodplain Integrated Planning (FLIP)
The FLIP process focuses on integrated solutions to improve the communities, farms, and fish in the Nooksack River’s floodplain ability to withstand the effects of flooding and rebound more quickly after flood events.
Integrated means addressing as many interests as possible while developing floodplain management actions. For example, a river levee modification project could also restore fish habitat and improve farmland drainage, instead of trying to address each need separately.
Solutions will be focused on creating resilience in the floodplain and reducing risks to communities even as flood events occur more frequently due to climate change.
FLIP Steering Committee and FLIP Teams of Contributors
The problems affecting the river and its floodplain areas cannot be solved by any one organization – it takes a coordinated group effort to achieve large-scale solutions. A steering committee representing all of the major interests in the Lower Nooksack River’s floodplains is guiding this work.
Members of the FLIP Steering Committee represent the following organizations:
- Whatcom County
- Nooksack Indian Tribe
- Lummi Nation
- Ag Water Board
- Cities of Everson, Ferndale, Lynden, Nooksack, and Sumas
- Washington State Department of Ecology
- Consultants
This committee meets monthly, and its members typically connect on a weekly basis in between meetings.
FLIP Steering Committee members, Lummi Nation members and staff, and University of Washington researchers during a field tour near Ferndale in February 2024, Source: Whatcom County
FLIP Mission and Goals
The FLIP mission is to develop a broadly-supported integrated floodplain management plan for the Nooksack River that will reduce risk to public safety, property, and infrastructure; with the goal to support healthy ecosystems and sustainable agriculture and fisheries that lead to viable communities now and into the future.
The FLIP goals are to:
- Reduce risk to public safety
- Optimize benefits to public infrastructure, private property, and to public resources such as salmon, salmon habitat, and water quality
- Provide a comprehensive understanding of the river, its form and functions and importance to resource-based economies including agriculture and fisheries
- Protect and maintain, and where feasible, restore river and floodplain habitats and habitat-forming processes
- Create a more resilient flood risk reduction system now and into the future
- Identify and prioritize a list of action items to implement the plan
- Build consensus around mutually beneficial outcomes
Reach Scale Work
FLIP covers a large geographic area that has high variability in river and floodplain characteristics. FLIP’s work is organized into several smaller geographic areas, called reaches.
For each of the five reaches, a “Reach Team” composed of 30 to 50 people (regulatory agency representatives, diking and drainage district representatives, elected officials and/or their staff, steering committee members, consultants, and others) meet several times to:
- Discuss shared values that provide a basis to develop strategies and specific actions tied to those strategies in the reach that can be widely supported
- Discuss and understand technical information that provides a foundation for defining problems and strategies to address those problems
- Define a range of potential actions to consider
- Discuss progress in analyzing potential actions
- Gain consensus on recommendations for strategies and actions to carry forward in the overall integrated floodplain management plan
Each reach has an initial meeting, called a design charrette, in which stakeholders attempt to resolve conflicts and conceive solutions. As of the start of 2024, detailed work in Reach 2 and the Flow Split (Reaches 1-3 and 5) was underway.
Webmap: Lower Nooksack River Reaches
Challenges with Predicting and Managing Flooding
Predicting and managing the effects of flooding for a dynamic river with a changing climate is a complex undertaking. Informed decision-making requires up-to-date scientific information, which takes time to prepare, evaluate, and share with others.
The decisions about how to manage flood hazards and risks must also reflect the wide range of opinions and perspectives of the affected communities and stakeholders- including those in British Columbia. It is similarly important to coordinate both within and across government jurisdictions and departments.
The FLIP process is bringing these parties together so that floodplain management efforts can be coordinated and comprehensive. Additionally, this enables elected officials to make the best decisions possible for projects and other actions that will provide long lasting benefits.
Photo: FLIP meeting participants sharing their personal values on a whiteboard in February 2020, Source: Whatcom County
Progress to Date
The FLIP effort began in 2017 with a series of large group meetings, resulting in a shared understanding of river processes and existing flood, habitat, and land use concerns among stakeholders.
More information can be found on the Nooksack FLIP web page:
Detailed work began in Reach 2 in early 2020. The major flooding in November 2021 led to prioritizing attention in the Everson area where the flow split originates; as a result detailed work in the Flow Split Reaches began in spring of 2022.
Information shared in reach-specific meetings can be found in these Nooksack FLIP web pages:
Photo: Nooksack River side channel enhancement project, Source: Whatcom County
Due to the November 2021 flooding, Whatcom County is proceeding to acquire several flood-prone properties (all with voluntary sellers), using funding from Federal Emergency Management Agency (FEMA) and Washington State grant programs.
Once those properties are acquired, the existing built features (such as homes and driveways) will be demolished, converting the land into open space.
Image: Site plan of an acquisition and demo project located south of Everson. Site plan is subject to change, Source: Whatcom County
Early Actions
While the reach-specific work is ongoing, the FLIP Steering Committee is emphasizing a need to implement projects and other actions that can reduce flooding risks and improve habitat conditions as soon as possible. These early actions have included:
- Improved drainage of floodwater and stormwater runoff on farmland by installing a larger flood gate in a levee, which also improves fish passage in streams draining to the river
- Levee repairs
- Enhancing a river side channel on a large gravel bar upstream of the Everson bridge
- Reinforcing an eroding section of river bank with log structures that enhance fish habitat while protecting a road and farmland
- Modifying comprehensive land use plans to strengthen flood protection requirements, so that future development and redevelopment is less vulnerable to flooding impacts
Photo: Duffner Ditch gate outlet, Lynden September 2021, Source: Mark Ewbank
The Landscape
Nature Conservancy Washington Episode: The Nooksack River Nature of Change
Natural processes create the landscape throughout the Nooksack River Watershed. Glaciers carve the valleys and carry volcanic sediment down from the mountains, depositing deep soils along floodplains and prairies. The temperate climate supports a rich and diverse ecosystem, including a wide variety of plants and animals.
Source: Richard M Hutchings (2003), Mid-Holocene River Development and South-Central Pacific Northwest Coast Prehistory: Geoarchaeology Of the Ferndale Site , Nooksack River, Washington. https://www.viurrspace.ca/items/56378fe6-fb5e-4237-ad1a-343283ba2eac/full
Yet, for most of the post-glacial period, the Lower Nooksack River followed a different path than it does today.
It used to flow north from the present-day City of Everson, north through Sumas Lake (which was drained to create extensive farmland in present-day Abbotsford, British Columbia), and ultimately into the Fraser River.
Most likely within the last 1,000 years, natural events led to the river gradually shifting its course to flow west into Bellingham Bay.
However, during large floods, the Nooksack River flow overtops its northern bank near Everson (at the “flow split”) flooding low-lying areas along its historic path through the Sumas River valley into Abbotsford.
For more information on the past and present course of the river and processes that have shaped its channels and floodplains, see this report:
Use the arrows to navigate through historic events that have affected the Nooksack floodplain.
01 / 09
Tribes
Reservation lands for Lummi Nation and the Nooksack Indian Tribe are home to many tribal members and tribal-owned businesses. Many more tribal members reside and operate businesses in other areas beyond the reservation boundaries. Flooding threatens their safety and livelihood, and historical river management and development affects their livelihood at all times of the year.
The intention of the Point Elliott Treaty as established in 1855 – to enable productive fishing, hunting, and gathering to continue for the tribes that signed it – has not been realized. This is because of:
- Subsequent land development caused dwindling opportunity for historically abundant fish, wildlife, and other native food sources to survive, and
- An inability of tribal members to access locations they historically used to fish, hunt, and gather.
Treaty fishing rights are as important as ever today, serving as a basis for the Nooksack and Lummi peoples’ attempts to maintain fishable populations of the once abundant salmon and trout in the river and several tributary streams.
Through Salmon Eyes Source: NW Treaty Tribes
Lummi Nation's Return to Reef Netting Source: NW Treaty Tribes
Historic Nooksack woven basket found on the river bank near Everson Source: Burke Museum
The Nooksack Indian Tribe is also concerned about preserving historical artifacts that could be unearthed in the river corridor. Many former tribal village sites, and places frequently used for fishing and hunting, were along the river.
Historical artifacts are prized cultural resources. An example of this concern is a basket that was found several years ago. It was determined by the University of Washington Burke Museum to be 425 years old, woven by a Nooksack ancestor.
See Lummi Nation’s website for information on their programs, interests, and cultural heritage:
See the Nooksack Indian Tribe’s website for information on their programs, interests, and cultural heritage:
Agriculture
The Nooksack River valley is one of the most productive agricultural areas in western Washington and its agricultural uses collectively provide the main source of income for many of the valley’s residents and workers. The area is known for its grains and hay, dairies, berry fields, and flower bulbs.
View of the Nooksack River and farmland between Hampton Rd and Polinder Rd, southeast of Lynden Source: Whatcom County
Agriculture is generally a compatible land use in the Nooksack River’s floodplains, with fewer homes and buildings, and lands that can more readily accommodate floodwaters. Flooding tends to occur outside of the crop growing season in the months of November through March.
However, flood events can directly impact the income of farmers and their employees in many ways. Some examples of flood impacts to agriculture include erosion of or sediment deposition across fields and croplands, flooding that prevents access along agricultural roads, or damage to crops, soils, or irrigation equipment from inundation or high flow velocities.
Mount Baker, Dairy Cows Source: Whatcom Farm Bureau
For dairy operators, inundation of pastures and barns can cause death and illness among their cows, reducing dairy productivity for extended periods of time. Slow drainage of flooded farmland is a common issue in the Nooksack River valley, preventing use of some of the land for livestock grazing and growing crops.
Farms in the Nooksack River valley are also affected by urban development pressure, increasing stormwater runoff from urban lands, and a lack of affordable living conditions for local workers. Future sustainability and potential growth of farming in the valley is directly affected by water resource issues.
See Whatcom Family Farmers website for information on their programs and advocacy work:
Fisheries
The Nooksack watershed supports eight species of salmonids (salmon, trout, and char) that are represented by more than 20 distinct stocks. Yet, three of the anadromous species (meaning fish that are born in fresh water and migrate to sea before returning to spawn in fresh water) found in the Nooksack River system are listed as Threatened under the federal Endangered Species Act (ESA): Puget Sound Chinook, Puget Sound winter and summer run steelhead, and Coastal/Puget Sound bull trout.
Other anadromous salmon and trout species in the Nooksack River and its tributary streams include sockeye, coho, even-year and odd-year pink and chum salmon, resident rainbow trout, and coastal and resident cutthroat trout. A coalition of groups has been working together for over 25 years planning and implementing salmon recovery projects throughout Water Resources Inventory Area (WRIA) 1, with a priority on early chinook habitats in the Nooksack River Watershed.
Maintenance and recovery of fish populations and fish habitat in the Nooksack River, and its tributary streams, is important to a wide variety of people who live in and visit the watershed. It is particularly vital to the Nooksack Indian Tribe and Lummi Nation, as both tribes rely on salmon and trout for subsistence, cultural, ceremonial, and commercial uses.
First Salmon Ceremonies and Blessings of the Fleet Source: NW Treaty Tribes
The FLIP work focuses on improving fish habitat conditions as it is essential for future floodplain management projects to integrate habitat benefits for a variety of fish species along the Nooksack River and its tributary streams. Projects that are defined and implemented as part of the FLIP process represent the best and perhaps only large-scale opportunity to accomplish WRIA 1 salmon recovery goals.
For more information on the WRIA 1 Salmon Recovery Plan, see link below:
Detailed information on fish habitat conditions in the Lower Nooksack River and its tributary streams is contained in this report:
Why the Nooksack River Floods
Flooding and flood risks along the Lower Nooksack River are caused by many interacting characteristics related to both natural processes and human actions. Understanding these characteristics is important for defining the most effective flood management strategies, while also protecting and enhancing the ecological and cultural integrity of the river ecosystem. Future Nooksack floodplain management actions need to address the causes in addition to the symptoms of problem flooding.
1. Flooding as a Natural Process
River flooding is a natural process. Floodplains connected to a river channel enable the flow to spread out and slow down, reducing the extent of flooding that occurs downstream.
Flooding in the lower river is driven by:
- The amount of rainfall over a few days to a week, especially in the upper watershed.
- The temperature when rain falls on snowpack in the mountains. Rain at higher elevations and melting snow adds to the runoff volume.
- Sediment effects as it moves through the system, reducing channel capacity along the way. The “flow split” that occurs when river water overtops its northeastern bank at Everson, is a natural situation tied to the historical flow connection of: the Nooksack River to the Sumas River valley and the Fraser River in British Columbia. This is described further in the “The Landscape” section above. This area appears to be particularly sensitive to sediment impacts.
- High tides in Bellingham and Lummi bays during high river flows. This often worsens flooding in Reach 1.
- Ice jams in the lower river can also affect portions of Reach 1, sometimes resulting in flooding when they break up.
Webmap: Nooksack River and tributaries
2. Human Factors
Traditional flood management strategies have relied on engineering controls, land use and development regulations, and floodplain drainage and backwater prevention systems to reduce flood risks in the Lower Nooksack River. These strategies are often successful for the smaller, more frequent floods, but less effective for the larger, less frequent flood events. Traditional strategies often come at a cost to habitat, water quality, and overall ecosystem health and function. They can also sometimes worsen damage due to larger floods when they provide a false sense of security, leading to increased land development in flood-prone areas.
- Engineering Controls- Levees and bank armoring have narrowed and straightened the river, forcing it to flow along a shorter path, and isolating it from historic channel pathways. These changes have reduced the river’s natural capacity to convey floodwaters. Most of the levees overtop in moderate flood events, storing floodwaters in the floodplain, but the levees often prevent them from getting back to the river. Levee repairs are often needed to continue providing a moderate level of flood protection.
Whatcom County completed a detailed study of levees along the Nooksack River and the forks that defined the locations and functional conditions of them:
- Floodplain Drainage and Backwater Prevention Systems- Flood gates are located on culverts that convey tributary streams through levees and are typically located near where the tributary enters the river. They are designed to close when the river is running high to prevent high river levels from backing up and flooding the lands behind the levee. This is important to protect crops during the growing season, but during flood season these areas are typically flooded by tributary runoff and upstream floodwaters. Webmap: Flood Gates and Levees
3. Sediment Effects on Flows and Flooding
Based upon analysis by the US Geological Survey (USGS), the Nooksack River carries the second highest sediment load – consisting of silt, sand, gravel, cobble, and boulders - of all the rivers draining the Cascade and Olympic mountain ranges into Puget Sound. When the slope of the channel flattens in the lower river, sediment settles into the river bed. Sediment movement and deposition occurs constantly there, with big flood events causing larger-scale changes.
Flow Split (Reach 5)
Over the past 20 years, sediment has accumulated upstream of the Everson bridge. The bank protections built constrain the river's ability to move side to side, hindering its ability to transport sediment downstream. With less capacity in the river channel for floodwater, the river overtops the bank at lower flows than it took 20 years ago. As a result of that change in the flow split, the volume of flow through the lower river has decreased during major flood events in this same period of time.
Reach 1
Sediment has been accumulating near the river’s mouth in Reach 1 ever since the river occupied its current channel alignment. The rate and extent of sediment deposition have increased in recent decades, resulting in shallower flow depths in the river channel throughout the year and causing former sloughs and side channels to fill in with sediment. This can impact flood conveyance during high flows and access to tribal fishing grounds during lower flows. Research and analysis by the USGS and the University of Washington Climate Impacts Group indicate that major, previously rare flood events will be more common in the future in this reach. This is due to warmer air temperatures, potential for increased rainfall intensities, and sea level rise. Sea level rise will cause more coastal flooding and will raise river flood levels when high tides coincide with major river floods downstream of Ferndale.
The results of a study by the USGS on sediment transport and deposition patterns in the Nooksack River between the years of 2006 to 2015 are provided in this report:
Webmap: Whatcom County 2022 Imagery. Pan or zoom into the map to navigate
4. Climate Change
Climate change is forecasted to increase the frequency and size of flood events in the Nooksack River watershed in the future. The glaciers on Mount Baker are shrinking due to increased rates of melting, which exposes more erodible soil to precipitation and increases sediment loads that are delivered to the Lower Nooksack River.
Research and analysis by the USGS and the University of Washington Climate Impacts Group indicate that what was previously understood to be a major, but rare flood event, will be more common in the future. This is due to warmer air temperatures, potential for increased rainfall intensities, and sea level rise. Sea level rise will cause more coastal flooding and will raise river flood levels when high tides coincide with major river floods downstream of Ferndale.
For more information on what causes flooding in the Nooksack watershed, see this storymap prepared by the University of Washington Climate Impacts Group:
Interact with the NOAA Sea Level Rise Viewer by clicking the "GET STARTED" button on the right or the link below. Zoom into the area of interest to toggle sea level rise predictions.
Source: NOAA Sea Level Rise Viewer
Flood Preparedness
Preparing for flood events is a critical effort to reduce the impacts on people, communities, and farms when flooding occurs. A lot of work goes into providing information to prepare for flood events and in planning for and executing emergency response activities during floods.
Measuring Flows
A primary source of information used to prepare for Nooksack River floods, and to inform response actions during floods, is using stream gages. A stream gage records flow rates at a specific location. This information allows for evaluation of the frequency and size of different flood events over long periods of time, and is used in real-time to support response actions when a flood wave is forming and moving along the length of the river system.
The US Geological Survey (USGS) operates and maintains several gages in the Nooksack River watershed. Some of these measure the water surface elevation only, whereas others measure flow rates (also called “discharges”).
Webmap: USGS Stream Gages 2024. Click the blue dot icons to see gage information. Click the "Real Time Reading" link in the Pop-Up box to see water data current conditions and 2023 conditions.
- The North Cedarville gage, located at the Mount Baker Highway crossing of the river at Nugents Corner, is the most useful for understanding the flooding that can occur in the lower river and Everson overflow. This gage has been in operation since October 2004.
- The Ferndale gage, located near the Main Street crossing of the river, has been in operation since October 1989.
- The Deming gage was operated from 1935 through September 2005.
- The USGS also has long-term discharge gages in place in each of the forks.
This chart shows the largest flood flows that have been estimated for the Deming, North Cedarville, and Ferndale gage locations since the USGS began operating them:
Whatcom County’s Flood Preparation Efforts
Emergency preparation for Nooksack River flooding is led by the Whatcom County Sheriff’s Office, through its Division of Emergency Management (DEM). DEM is responsible for providing emergency management services for all of unincorporated Whatcom County and for the cities of Lynden, Ferndale, Blaine, Sumas, Everson, Nooksack, and the Port of Bellingham.
This large geographic area includes all of the Nooksack River floodplain areas addressed by FLIP. DEM coordinates its work with a variety of local and regional utility providers, cities, the Whatcom County River & Flood Division, fire stations/districts, hospitals, schools, electrical substations, and other “critical infrastructure” owners.
Whatcom County’s River & Flood Division provides additional information and resources specific to preparing for flooding hazards as described on its website:
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