People have relied on what we call Maxwell Lake and the surrounding watershed for thousands of years, for water, food, and other resources provided by the forests. These forests support a range of wildlife, cougars, bears, songbirds, waterfowl, amphibians, fish and beavers. The tall crowns of coastal Douglas-fir trees reach for the sky with large, drooping branches that cast shadows over the ground below. There are also open patches in the forest, where trees have fallen, allowing those left standing and understorey plants like salal and Oregon grape to thrive. Wet meadows and wetlands are common. In spring, when the Northern red-legged frog starts to call, the flowers of red alders growing along wetlands edges emerge, providing an important food source for native bumblebees. And seasonal creeks meander slowly toward Maxwell Lake.
Maxwell Creek Watershed Today:
This describes the Maxwell Creek watershed in full vibrancy. It describes how it likely looked a century ago, before 80 years of intensive logging, wetland draining, road construction and other land use activities modified the waterways, hydrology and local forest ecology.
Today, the Maxwell Creek watershed, located on Mount Maxwell at the heart of Salt Spring Island, is far from thriving. The watershed has experienced a history of logging, thinning, and replanting in the last Century, as well as agriculture, all of which altered the wetlands and watercourses. These changes have influenced the supply of water to Maxwell Lake, which provides drinking water for almost half the population of Salt Spring Island. Some former wetlands are now seasonal (also known as ephemeral), and the forest lacks the structural complexity it once had. As a result, the watershed is now more vulnerable to drought and fire. Climate change is expected to amplify these risks.
Current Work at the Watershed:
Currently, a diverse team of scientists and restorationists are working hard to undo the adverse effects of the past century and enhance healthy ecological functionality in the Maxwell Creek watershed. A main goal of this project is to enhance the forest’s resilience to wildfire by 1) re-naturalizing the Rippon Creek system and 2) re-establishing conditions that more closely resemble the historic watershed conditions.
More specifically, work will be undertaken to restore wetland pockets and riparian stretches that extend from Dry Lake in the southeast margins of the watershed, up to Maxwell Lake. By creating a more prominent riparian network, this will serve as a natural fire break and buffer zone that can prevent the spread of catastrophic wildfires across the landscape, protecting the forest and surrounding human residences. Additionally, the re-establishment of wetland habitat will provide more soil moisture to the forest area, making the forest less prone to future wildfires.
Learning from Nature:
Typically, nature does a remarkable job of restoring itself. Take the North American beaver (Castor canadensis) for example. Colloquially known as nature’s engineer, beavers play a crucial ecological role in creating and maintaining riparian and wetland habitats. Yet, this essential role has historically been misunderstood and overlooked. In the 18th century, beavers were nearly eradicated by the fur trade. Today, beavers are often viewed as a nuisance because of their tree-felling activities, which can sometimes cause local flooding.
As ecosystem engineers, beavers are one of the few animals that can change the geomorphology and hydrology of the landscape. Dam building modifies hydrology and local ecosystems in ways that increase biological ecological complexity and increase water retention in soils and ground water recharge. Further, the foraging habits of the beaver encourage the growth of plants and trees it prefers due to the cellulose content (their favourite foods). This leaves behind woody materials that provide habitat for other species and enhance soils. Perhaps their most important role is in reducing stream flows and water retention, reducing erosion and sedimentation, and slowing the movement of water in streams.
In other words, beavers are able to undertake the type of restoration needed to reduce fire risk and improve water supply. But very little beaver activity has been observed in the Maxwell Creek watershed. There is simply not enough of the red alders and other vegetation they need in this modified watershed. So, as we move toward restoring wetland areas, and alders and other beaver-preferred plants return, we hope to see the return of beavers to take back their role as hydrologic engineers.
Much restoration involves mimicking nature, in the Maxwell Creek Watershed example, one way we will do this is by temporarily taking on the role traditionally filled by beavers by installing beaver dam analogs. Beaver dam analogs can be formed in different ways, but usually make use of low-cost materials such as sticks, mud, and rocks found on site. Once installed, several dam analogs can be placed downstream from one another, achieving similar hydrological outcomes as natural dams thus restoring wetland areas.
Such installations are increasingly used as tools for wetland restoration. They can encourage natural repopulation by wetland species, including beavers, and help to slow and retain water within the watershed. Over time, water slowly infiltrates into the soils and rock fractures, restoring ground water. This delayed water flow below ground (ie. through aquifers) is important because it continues to deliver water through summer drought periods; this can help offset evaporative losses from waterbody surfaces during periods of drought and extreme heat. In this way, installing beaver dam analogs will support Dry lake throughout the year. This will improve climate change resilience in the Maxwell Creek Watershed.
To put it simply, restoration approaches to ‘managing land’ seek to establish conditions that will allow nature to ‘take care of itself in the long run. While dam analogs can increase initial water retention, they cannot outperform the long-term standards of beaver complexes, which are integrated with watershed systems. Due to the degraded state of the Maxwell Creek watershed and its lack of ecological integrity human intervention is needed to restore wetlands and functional watershed conditions. Ultimately, we aim to restore the ecosystem conditions that will attract and sustain new beaver families. Until then, our work here is far from over.