The world’s largest beaver dam was discovered in 2007, and it lies within Wood Buffalo National Park, a remote section of the Canadian wilderness spanning Northern Alberta and the Northwest Territories.

The dam is almost a half mile across, and its arcing build is composed of smaller, interconnected arcs. Its discovery was the work of Jean Thie, a Canadian landscape ecologist. By comparing images from NASA’s Landsat satellite taken in the 1970’s with Google Earth views, Thie identified the dam and its companion 17-acre lake.

Beaver dams, much like human made dams, help to minimize flood risks and store water during periods of drought. In instances of flooding, beaver dams lower flood risk by slowing the flow of water, which can reduce peaks further downstream.

Yet, the world’s largest beaver dam in Wood Buffalo National Park serves a different purpose: it’s a larder. Drawing from the Black Mountains’ spill off, the beavers have created a lake ripe with plants to eat.

When it’s time for the beavers to change grazing grounds, they relocate to another one of the dams in the complex. These smaller constructs are about a third the size of the beaver’s record-breaking dam, and they are believed to be components in the animal’s ability to adapt to drought.

The lake formed by the world’s largest beaver dam in Wood Buffalo National Park, Canada. (Image courtesy of Parks Canada)

DRAWING FROM THE SOURCE

Inspired by the benefits of beaver dams, beaver dam analogs (BDAs), which are human-built structures, have been implemented by conservation groups to mirror the natural benefits of beaver dams by slowing streamflow and gently raising water levels.

Constructed from materials local to the area, like logs, brush, and mud, BDAs create small pools and backwaters that improve fish habitat and increase overall stream health.

These low-tech approaches reflect the same ecosystem-shaping role beavers play naturally by enhancing habitat, improving resilience after disturbances (wild fires), and supporting diverse plant and wildlife communities through nature-based design.

The National Forest Foundation have utilized BDAs in their work, targeting areas where the benefits of beavers would be a boon, and then employing low-tech, process-based restoration. In Colorado’s Trail Creek, two years after application of BDAs, beavers began to move back into the area, where they constructed dams of their own.

A beaver dam analog on Soda Creek, White River National Forest, Colorado. (Photo courtesy of Kellon Spencer)

PLANTING THE FLAG

Only one person has ever been to the world’s largest beaver dam: Rob Mark, a blueberry farmer and member of the New York City-based Explorers Club, which was founded in 1904, and has a history of “supporting scientific expeditions of all disciplines” ever since its inception.

In 2014, Mark, who planned the expedition for over three years, faced the true challenge of the wetlands when he was brought by boat to a remote section of Wood Buffalo National Park. From his drop-off point, Mark trudged for more than two days to reach the dam.

When he came across the dam, Mark estimated it stood about three feet high. After taking a selfie with the Explorers Club flag, Mark began the three-day process of hiking back to his pick-up spot, becoming the 851^st member in the club’s history to carry the flag on an expedition – a notable group of alumnae that includes director James Cameron.

Selfie of Rob Mark at the ‘World’s Largest Beaver Dam’ (Photo courtesy of Rob Mark)

EXPLORING THE PARALLELS

The world’s largest beaver dam underscores a simple truth: the intelligent management of water is foundational to resilient landscapes and thriving communities.

Hydro applies this time-tested relationship between water and infrastructure at a larger scale, transforming managed flows into dependable electricity while continuing to provide flood moderation, water storage, and system stability.

Just as beaver dams quietly work in balance with their surroundings, hydropower projects can serve both the needs of humans and river systems, offering durable, long-term foundations for energy and water resilience.