The Rebirth of an Ancient Pond

The excavation of a pingo and what happens next.

Out where thigh-high grass sways in the breeze and thrums with crickets, a digger sinks its bucket into the soil. It cuts through the long grass, the roots beneath, the pale sandy earth below, strewn with flint and farm debris and spent military cartridges until its teeth touch a black, peaty surface. It stops there, revealing a black crater at the edge of the field.

Stepping down into the hole, we are standing on earth that was on the surface hundreds, perhaps thousands, of years ago. Over the next couple of hours, this new crater will fill with water, seeping through from beneath the ground until it creates a pool. This is when the black earth below will give up its secret: buried in this layer are ancient, dormant seeds. Now uncovered, they will wake and germinate and send up green shoots. In less than two years, this pool will be thriving with ancient plants reborn, teeming with insects and home to amphibians too, maybe even the extremely rare pool frog.

This is what Norfolk Wildlife Trust are doing, not digging new pools or even creating new habitats, but re-establishing ancient ones.

During the ice age, the area around Thompson Common was in flux, a constant state of freezing and thawing. This continual change created small, conical hills of ice all over the landscape which melted and collapsed into shallow craters which became natural pools. These are called pingos.

Since then, the land has been drained and used for farming. Generations of farmers and military units have filled in the pingos with stones picked from the fields, earth from elsewhere and even rubbish.

Norfolk Wildlife Trust has been slowly finding and returning the pingos to the land. Over the course of the BFER Lost Ponds project, 14 pingos have been restored and, in August, in a special showcasing event, a 15th was dug out, with land managers, ecologists, geologists and archaeologists present.

Pond-dipping in a 2 year old pingo. Image credit: Jimmy King

We also visited a few established pingos and learned that each one has its own character. Once dug out, left to grow themselves, they have their own unique qualities and habitats. Some are small and perfectly circular, some sprawling and higgledy-piggledy. One was wildly fragrant with water mint and covered with bees, another had none and, instead, was circled with the green pompom-bearing branched bur-reed.

Biodiversity surveys are currently being carried out and a final report for the project created – we can’t wait to see who is living in these beautiful ancient ponds!