What is underneath all that water on Sumas Prairie?

Photo courtesy Peregrine Aerial Surveys Inc.

• Our story on the potential for more flooding from the Nooksack River this winter

• Our investigation into the failure of the Sumas dike, and the reasons other levees are doomed to fail in the event of an even worse flood from the Fraser

• Our comprehensive story on the challenges Fraser Valley dairy farmers are facing

• Our comprehensive story on the history of Sumas Prairie, Sumas Lake, and the Nooksack River

When water from the Nooksack River poured into Canada last week, it flooded one of the most intensively farmed areas of Canada: Abbotsford’s Sumas Prairie, where hundreds of properties are now underwater. And we know quite well the composition of the farms that have been swamped with water the last week.

A wide-ranging survey recently conducted by the City of Abbotsford, combined with Census of Agriculture figures from Statistics Canada, allows us to see what grows where on the prairie at a level not possible in many other communities.

But first, let’s take a detour into why there are so many farms on Sumas Prairie—and you guessed it, Sumas Lake again plays a key role. (You can read our history of Sumas Lake and the impact it is having on the Fraser Valley’s flooding here.)

The Fraser Valley is one of Canada’s most fertile farming regions, for which it can thank periodic floods from the Fraser River. Those waters brought nutrient-laden silt with them, which enriched the soil as the flood retreated. (Dead fish left behind by floodwaters also did their part to enhance the soil.) Rich silt also came into Sumas Prairie from the floodwaters of the Nooksack, to the south.

Sumas Prairie’s fertile soil, however, is more a result of Sumas Lake. The region has varied soil types. Around the edge of the lake bed and near the highway, the soil is relatively sandy, allowing for crops like carrots and potatoes, which need more air in the soil. Further into the prairie, the soil has a finer texture due to the years of silt and clay build up from the relatively still water in the lake.

These waters deposited nutrients into the soil over the course of generations. Today, modern-day floods don’t bring so many benefits. The 2020 Nooksack overflow report noted that a major flood could spread bacteria from manure pits, chemical contamination like pesticides, and other pollutants like asbestos.

Until the waters recede, there’s no way to know what kind of contaminants will be settling on Sumas Prairie, soil scientist Rose Morrison explained. But even without the extra pollutants, the floodwaters will be creating major problems for the prairie’s farmland.

“Soils are a great big web of life, and that is being disrupted,” Morrison said.

The first change will be the physical effects. The sheer weight of the water will have compacted Sumas Prairie’s normally well-aerated soil, reducing the amount of oxygen available.

That will have killed the fungi, beneficial bacteria, and untold numbers of earthworms that normally live in the dirt. Plant roots will be starved of oxygen as well, and essential nutrients like nitrogen may be leached from the soil. Topsoil—the most important part of agriculture and a finite resource in Canada—will likely have eroded from fields and moved to places where it is less useful, such as roadways or even into the Fraser, where it will be dumped into the ocean.

Farmers and governments will only be able to begin analyzing the prairie’s soil once the water drains from the fields.“They’ve got a long, slow road ahead of them,” Morrison said. “I think they’re going to be looking very far into the future and making the best decisions they can.”

But we’re not there yet. And right now, farmers and residents are still focused on the crops and livestock trapped under the Nooksack floodwaters. Those include fields of carrots, potatoes, cabbage, broccoli, and lettuce, as well as barns of poultry and cattle, and corn fields currently planted with cover crops for the winter.

For now, this is what lies under the flood debris of Sumas Prairie.

Note: unless otherwise noted, all numbers are from the 2016 Census of Agriculture and for the City of Abbotsford as a whole—not just Sumas Prairie. Statistics Canada does not share agricultural data at a smaller level.

Vegetables

Nearly all of Abbotsford’s vegetable crops are grown in Sumas Prairie, largely centred in the former Sumas Lake bed. Sweet corn, potatoes, and cruciferous vegetables like cabbage and broccoli are the most common. The majority of the sweet corn in the Fraser Valley is grown in Abbotsford: 1,152 acres out of the 1,620 valley-wide. (Although this may seem counterintuitive due to the number of corn fields in Chilliwack and the marketing around Chilliwack corn, the Census of Agriculture has Chilliwack down for only 462 acres of sweet corn.) Combined, Abbotsford had 810 acres of cruciferous vegetables in 2016, with broccoli being the most popular at 558 acres. There were also 175 acres of potatoes being grown in Abbotsford—around half of all potato crops grown in the valley.

Berries

Berries are an important staple for Fraser Valley farmers—particularly blueberries, which make up 75% of all berry farms. In Abbotsford, there were 420 blueberry farms in 2016 growing more than 7,500 acres of crops. And although blueberries are the most common berry grown in Sumas Prairie, many more are grown in Matsqui. There were also a very small number of raspberry plots of Sumas Prairie, although these are more common west of Huntingdon.

Poultry

Each year, Abbotsford produces around 39 million table eggs—more than half of all the eggs produced by the province of BC. A significant number of those eggs come from farms on Sumas Prairie, though other parts of the city have an even higher concentration of poultry operations.. Across Abbotsford, there were 1.6 million laying hens producing eggs, as well as nearly 720,000 young birds that will be laying eggs when they reach 19 weeks old. There were also 7 million broiling, roasting, and Cornish hens in the region. In 2016, Abbotsford had 70 chickens for every one human.

Dairy cattle

The majority of Abbotsford’s dairy farms are located on Sumas Prairie—and these farms are typically the largest dairy operations by parcel size in the city. Across Abbotsford, there were more than 16,000 dairy cows, as well as 7,935 heifers for dairy herd replacement. Bulls, which are not typically kept on site at dairy farms but are vital for ensuring the cows can get pregnant and then produce milk, numbered just over 150 across the city. Across both the beef and dairy farms, there were more than 8,600 calves under a year old. (To see how the flooding has affected dairy farmers in particular, read the Current’s story on the dairy crisis from last week.)

Beef cattle

Most of Abbotsford’s beef herds are located outside of Sumas Prairie. Those that are on the prairie are sometimes raised in conjunction with dairy or horse operations. Across Abbotsford as a whole, there are 892 beef cows, as well as 927 steers (castrated male cattle which are primarily raised for beef, although they can be used as working oxen), 206 heifers for replacing beef herds, and 692 heifers for slaughter. Across both the beef and dairy farms, there were more than 8,600 calves under a year old.

Forage crops

In order to support the more than 35,500 cattle in Abbotsford, farmers grow forage crops. In Sumas Prairie, most of these crops are either corn or grass. A very few fields grow a mix of grass and legumes. Across Abbotsford, there were around 7,000 acres of corn that would be made into silage, a type of livestock feed that has been preserved by fermentation—essentially pickled—so the animals can eat it when natural pasture isn’t available. (The plastic-wrapped bales you see on fields are an important part of producing silage, as the plastic creates an environment where anaerobic bacteria can flourish and ferment.)

Other livestock

Not all livestock can be neatly divided into poultry and cattle; there are a number of farms on Sumas Prairie and elsewhere in Abbotsford that raise animals such as pigs, sheep, llamas, and mink. In all of Abbotsford, there are 39,760 pigs, 1,560 sheep, 476 goats, 139 rabbits, and 100 llamas and alpacas. (Abbotsford is also home to four of the region’s six mink farms, although it’s unclear if these are located on the prairie.)