Thread by @leeinthelakes

A thread on why nature conservation needs to go underground...

Yesterday, while I was kneeling in the grass putting tree cages together, I heard the sound of running water coming up through a hole in the soil, probably dug by a mole.

I grabbed a spade and started digging. Two feet or so down, the spade hit a flat stone with a hollow thud, the sound of running water now louder from below. I dug around it, to find the stone was interleaved with two others, making it hard to lift.

Enlarging the hole to expose all sides of the flat stone, I managed to lever it up and out, exposing a neat, square channel, through which a clear running stream was babbling away.

The channel was incredibly well made, and had likely had water flowing through it for centuries. Overlapping flat stones with small gaps between them, topped with a layer of gravel allowed water in, but prevented soil falling through, ensuring the drain would be maintenance free.

If I were to have kept digging, I'd have found that the channel would have run the whole length of the field, and it wouldn't have been the only one. Put a digger bucket in the ground almost anywhere in a field in a wet part of countryside, and you'll find the same thing.

Over the course of centuries, astonishing amounts of labour have gone into land drainage. The toil and the skill involved are easily comparable with the construction of the thousands of miles of dry stone walls which criss-cross our upland landscapes.

Imagine the work involved in digging trenches, hauling and sorting vast amounts stone, building the chambers, all of it by hand in wet mud. No maps exist of these drains, but there are undoubtedly thousands of miles of them flowing away beneath the ground.

Draining the land was one of the many innovations that allowed people living in the unforgiving terrain of the uplands to survive. The wetlands that existed prior to land drainage would have been near impossible to grow crops in, unappealing to livestock and hard to traverse.

The drainage network has lowered the water table, in many places by several feet, drying the soil to allow it to be worked, tilled and grazed. An incredible undertaking. But one that we are now paying a high price for.

In our rapidly changing climate, flooding is becoming more frequent and increasingly devastating. Drainage has optimised the landscape to shed water as quickly as possible, accelerating the speed with which it is shed from high ground to low.

Sending water downstream as fast as possible makes if you're an upland farmer, but downstream is where almost all the population lives.
BBC News - Carlisle flooding causes major travel disruption - BBC News
bbc.co.uk/news/articles/…

There is growing awareness of the harm done by moorland drainage, and of the need for restoration. In higher, steeper ground, drains were usually left open. Unless land was to be tilled, there was no need to cover them, or to make them as deep.

This makes the drainage of unenclosed land, and the damage it's done, far more obvious. But the buried drains running below enclosed land has done just as much environmental harm.

It's reckoned that we've lost 90% of our wetlands, and most of that will be down to drainage. I find it hard to envisage just how much wetter and richer the land must have been before it was drained. The abundance of wildlife would have been mind-blowing.
naturalengland.blog.gov.uk/2024/02/02/wet…

Anyone who has dug a pond knows just how quickly wildlife responds. Dragonflies and other insects find open water with astonishing speed. Birds and amphibians quickly follow. Imagine that scaled up to the landscape level, and how impossibly rich our countryside must have been.

Although there is no real prospect of restoring our lost wetlands in their entirety, there is still lots that can be done. While digging these ponds on the farm a few weeks ago, we found stone drains 7ft down. Blocking them has brought the water back into the light.

Here's another example, down the valley on the Lowther Estate. This tarn (as yet unnamed) sprung into being by removing a single large underground drain. Lapwing bred on its muddy edges the first spring after it was made, and it's busy with birds all year round.
(📷 Tony Rumsey)

When we did the river restoration work in Swindale, we cut through drains every few yards. There were deep stone drains, as well as, concrete, clay tile & plastic ones. Every digging project I've been involved with in Cumbria has found them. Basically, they're everywhere.

We refer to the thousands of miles of tunnels under the soil as drains, but we should really call them what they are - buried rivers, sunken lakes and vanished wetlands. And then we should accelerate the work of bringing them back to the surface.