06/25/2026
Take the trees out β then ask where the water went. The connection between the two is almost never explained. π
What a tree actually does with rain:
Tree roots open vertical channels in the soil, reaching as deep as two to three metres under mature trees. When rain falls on wooded ground, it follows these channels downward instead of running off the surface. It percolates through the organic humus layer, which works like a sponge, then through clay and silt, then slowly down to the subsoil and rock beneath. That water feeds the groundwater. A spring lower down keeps flowing because the water table above it is constantly being topped up.
What happens when the trees are removed:
Rain falls on bare, compacted ground. With no root channels to guide it down, it runs across the surface β and takes the soil with it. It reaches streams as fast run-off, causes flooding lower down, then pours away towards the sea. Nothing reaches the groundwater. The water table stops recharging, springs dry up, and the compacted soil loses its ability to soak up water at all.
Why this matters in your own garden:
Every mature tree in your garden works as a small water-infiltration system. Its root network helps direct rainfall down into the ground rather than letting it sheet off towards the road or drains. Removing a large tree β especially on a slope β doesn't just change how the garden looks. Over time it changes how that piece of ground handles water, and you may notice more surface run-off or a wetter, more compacted lawn afterwards.
Replanting with deep-rooted native trees rebuilds this function over the years: pedunculate oak on general ground, alder in damp spots, white willow along water, ash where it's healthy to do so. The result shows over decades β not at once, but measurably.
A tree doesn't hold water on the surface. It sends it underground, where it lasts π³