SUMMER 2014 PEG | 53

Like humans, the North American beaver — Castor canadensis — can alter the natural landscape to meet its own needs. In the remote wildlands of northern Alberta, a bevy of busy beavers has been doing just that, and with great success. For the past four decades or so, they’ve been hard at work building the world’s longest beaver dam

Visit the Town of Andrew and you’ll find the world’s

largest mallard duck. There’s a giant baseball bat in

Edmonton, a nine-metre tall cornstalk in Taber and a

replica of the Starship Enterprise in Vulcan, among dozens

of roadside attractions across the province.

And in the remote wetlands of Wood Buffalo National

Park, about 190 kilometres northeast of Fort McMurray

near Lake Claire, you’ll find the world’s longest beaver

dam. A real beaver dam, that is. At approximately 850

metres long, it’s about the length of 14 NHL hockey

rinks.

Ontario ecologist Jean Thie discovered the

lengthy lodge in 2007 while studying Google Earth

satellite images, part of a project to track melting

permafrost in Canada’s boreal and sub-Arctic

wetlands. By analyzing old aerial photos, he was able

to determine that the eager beavers started their work

in the 1970s.

LOCATION, LOCATION, LOCATION

How did the world’s largest beaver dam remain hidden for

so long? Well, for one thing, Wood Buffalo National Park is

larger than Switzerland, and the area the beavers built their

dam in is remote and undisturbed. The rascally rodents must

be pleased with their accomplishment: no significant growth has

occurred since the dam was discovered.

The previous record holder was a dam near Three Forks,

Mont. It was 652 metres long and four metres tall at its highest

point.

Leave It To BEAVERS

FOCAL POINT

54 | PEG SUMMER 2014

FOCAL POINT

Ecosystem

EngineersOver the years, their habit of flooding

roads and farmland and chopping

down trees has earned beavers a

bad rap. Love them or hate them,

research shows that they’re also

amazing ecosystem engineers,

helping preserve water resources,

reduce the effects of drought and

increase ecological biodiversity.

University of Alberta biologist Dr.

Glynnis Hood, author of The Beaver

Manifesto, calls beavers hydrological

engineers. Her research examining

the historical records of beaver

populations and climate data in Elk

Island National Park found that ponds

with active beaver lodges had nine

times more water during periods of

extreme drought than ponds without

dams.

Beavers may also help with flood

mitigation. Dr. Cherie Westbrook, an

ecohydrologist with the University of

Saskatchewan, has studied beaver

activity in Kananaskis Country

since 2006. In an interview with the

Calgary Herald in March, she said

that when flooding hit the region last

June, beaver dams in the area acted

like a storage system, retaining and

slowing the flood water.

Other research has found that

beaver ponds help remove sediment

and pollutants from streams, reduce

soil erosion and provide habitat

for birds, insects, fish, amphibians,

reptiles and other mammals.

wetlands

The dam

is situated

in prime

wetlands between

the Birch Mountains Wildlands to

the south and the Peace Athabasca

Delta to the northeast. On its

website, Parks Canada notes that

run-off from the wildlands provides

the beavers with plenty of water

while the dense boreal forest

provides them with food and wood.

The beaver, coincidentally, is also

the symbol of Parks Canada.

The Surficial

Geology Map of

Canada shows the

parent materials

present in this area

are silty and sandy

alluvial material

washed down

from the hills and

slopes of the Birch

Mountains Wildlands

to the south and

modified by glacial

lake action.

SUMMER 2014 PEG | 55

FOCAL POINT

Special thanks to Jean Thie (geostrategis.com) for statistical information on the world’s longest beaver dam.

The dam has at least two

or more lodges and was

formed when two original

dams merged into one.

The world’s longest beaver dam is approximately 850

metres long, or about the length

of 14 NHL hockey rinks. It’s

virtually inaccessible, located in

the remote wetlands of Wood

Buffalo National Park, about 190

kilometres northeast of Fort

McMurray near Lake Claire.

Despite its length, the dam

is no more than one to two

feet in height, which is

common for wetland dams.

There are several other

dams in the area; the next

longest is about 400 metres.

wetlands

wetlands

wetlands

Water flow in the area is

slow and spread over a wide

area of wetlands, forcing the

beavers to build longer dams

to stem the flow.

direction of ground water flow

56 | PEG SUMMER 2014

FOCAL POINT

Beaver SymbolismParliament made the beaver an official emblem of Canada

in 1975 but beavers have long been a symbol used by

Professional Engineers and Geoscientists in Alberta.

An image of a beaver is available on APEGA’s stamp and

seal. APEGA history buff Dr. Gordon Williams, P.Geo., FGC,

FEC (Hon.), a past President of APEGA, did some digging.

Here’s what he was able to track down about the origins of

the beaver on the stamp and seal.

APEGA has both a corporate stamp and seal, used on

the Association’s official documents, and another used by

Members to authenticate their work.

The original Engineering Profession Act of 1920

underwent a significant revision in 1930 and the APEGA

Council of the day decided a new stamp and seal was in

order. Why they selected a beaver cutting down a tree in a

field of stumps to characterize

the Association remains

a mystery, but it was

first used as early

as 1931.

The Member

stamp has also

changed over

the years. The

current design,

with the symbolic

beaver, has been in

use at least since the

1950s.

COLLECTORS ITEM

This antique brass seal, designed by

APEGA’s predecessor, the Association

of Professional Engineers of Alberta,

shows a beaver chomping down on a

tree. It was for sale online for $125,

but was purchased by a lucky collector

— perhaps an APEGA Member?

-photo courtesy aubreysantiques.com

CLASS ACT

The University of Alberta Faculty of

Engineering logo features a beaver

gnawing on a stump.

-image courtesy University of Alberta

ROYAL RODENT

Various military regiments use the

beaver as their emblem, including

Canada’s Military Engineering Branch.

-image courtesy Canadian Armed Forces