About water, plants and time
Across Grimsby and much of the Niagara Region, the last couple of weeks brought significant rainfall.
Flash flooding damaged roads, overwhelmed creeks, and left many gardens with washed away soil, displaced stone, and debris carried in by fast moving water.
In one garden I work in, the force of the water was enough to move large potato stones. Seeing rocks that size carried away by water is a reminder that landscapes are not nearly as static as they often appear.
We often think of land as something permanent. Our homes stay in the same place. The furniture inside rarely moves. At the pace of everyday life, it is easy to assume the landscape is equally still.
It isn’t.
Waterways shift. Slopes slowly change. Wind moves sand. Streams carve valleys. Floods happen, and as our climate changes, many places are experiencing them more often.
As gardeners, we often think of erosion as something to repair after it happens. Replace the soil, put the stones back, tidy the garden, and move on.
But storms ask a different question.
Not How do we repair this?
Instead:
How do we prepare for the next one?
That is where erosion control really begins.
Or perhaps more accurately, where we begin designing with water instead of against it.
Water is always moving
Water has always shaped the landscape.
Niagara Falls exists because of erosion. Over thousands of years, the falls have slowly carved their way upstream through the Niagara Escarpment. Smaller waterfalls, like Beamer Falls here in Grimsby, continue the same process today, only on a different scale.
Erosion is not unusual.
It is one of the ways landscapes change.
The goal is not to stop that change entirely. The goal is to understand how water moves through a landscape, and to work with those patterns.
Thinking in functions
When water moves across a landscape, it usually removes the lightest material first.
Sand moves before gravel.
Loose soil moves before larger stones.
Even clay can be washed away when the flow is strong enough.
When thinking about erosion, I find it helpful to think less about specific materials and more about the jobs they perform.
Some elements are obstacles.
Large boulders, mature trees, berms, and well placed hardscape slow or redirect water. They absorb energy and protect what lies behind them.
Other elements are facilitators of flow.
A smooth stone surface, or a stand of grasses, allows water to move through. Some surfaces accelarating water, some reducing its energy. Either way, rather than forcing water to stop, they guide it where we want it to go.
Good erosion control usually combines both.
Some elements redirect.
Others allow movement.
Together they shape how water travels through the landscape.
The real work happens below the surface
Most of the important, influential, and reliable work often happens below the surface.
What holds a landscape together is not simply what we see above ground, but the relationships beneath it.
Roots connect individual particles of soil into something much more difficult for water to move.
Different plants do this in different ways.
Trees and shrubs anchor the deeper layers of soil.
Grasses and sedges create dense fibrous networks that hold the surface together.
A healthy landscape uses both.
It is a multi layered system where different root depths and different root textures work together. The deeper anchors stabilize the slope, while the finer roots knit the surface together.
The real work is happening below the surface.
Small decisions, long consequences
One of the best known examples of this is the Dust Bowl of the 1930s.
Large areas of native prairie were converted to farmland, removing the deep rooted grasses that had held the soil together for thousands of years. When drought and strong winds arrived, enormous amounts of topsoil were carried away.
Closer to home, a similar story unfolded at Sandbanks Provincial Park. Trees were cleared and cattle grazed the dunes, removing the vegetation that stabilized the sand. Over time, the dunes began to move, burying roads, orchards, and even buildings before restoration efforts eventually began.
Different places.
The same principle.
Small decisions made upstream often have consequences that appear much later.
Designing for the next storm
When clients ask me how to control erosion, I understand the question.
But I often find myself asking a slightly different one.
How do we design for the next storm?
Sometimes the answer is immediate.
Large boulders, retaining walls, or reshaping the land can quickly redirect water and protect vulnerable areas.
Those are important tools.
What interests me most, however, is what plants quietly accomplish over time.
A native grass like big bluestem (Andropogon gerardii) or switchgrass (Panicum virgatum) may not look like much in its first year. Give it three years, and it has developed an extensive root system that is quietly holding the landscape together beneath the surface.
In shaded areas, various native Carex species perform a similar role, weaving dense fibrous roots through the upper layers of soil.
For structure, especially in frequently flooded sites, red osier dogwood provides both strong roots and resilient growth.
These are upstream decisions.
A relatively small action, taken at the right time, whose effects may not become obvious until years later.
That is one of the things I enjoy most about gardening.
The best solutions are often the small, simple ones, that evolve over time.
Good erosion control is less about fighting water than it is about helping the land hold itself together. It continues working long after we’ve gone home.