In 1956 the Pitsford stream was dammed and Pitsford Water created. The 2.85 square miles of water quickly accrued wildfowl, and it was declared a site of special scientific interest in 1970.
Today the air is still, the water gently rippling, the ground frosty, and the low sun shines brightly in a clear blue sky. Along the northwest shore, grey trunks and the reddish branches and twigs of bare willows glow in the sunlight; they are flecked with black and white – perched cormorants and little egrets. The radiance picks out noisy skeins of Canada geese and flashes back bright and green from the heads of drake mallards.
A grey heron perches, hunched on a dead branch projecting over the water’s edge, out of the icy water but watching it intently, its yellow dagger of bill pointing straight, horizontal and motionless. A smew swims past; small, grey, with a reddish crown and brilliant white cheeks; it lifts away on delicate grey-ended, black and white striped wings.
Overhead hundreds of wood pigeon stream past, making me imagine how impressive it must have been to see billions-strong flocks of passenger pigeons black out the American sun, before they became extinct 101 years ago.
The reservoir shore, subjected to fluctuating water levels, is known as the drawdown zone. Here at Pitsford the shingles and clays became home to a considerable range of wildlife that thrives only on erratically flooded water margins, particularly orange foxtail, golden dock and mudwort: very uncommon plants. Mudwort is a particular little treasure; the rosette of thin paddle-shaped leaves and tiny white star-flowers would fit in your palm, but it is sought by eager botanists.
However, this drawdown zone has a problem. Green lawns of New Zealand pygmyweed swathe some of the exposed patches of sediments. This invasive alien is a worry for the delicate shore ecosystem, swamping out plants in its vicinity.
But the convoluted margin of Pitsford Water is extensive, so there is hope that the special plants will weather the invasion.
