How Chimney Meadows plays an important role in preventing flooding

Chimney Meadows holding floodwater by Louise King

Nature reserves on floodplains play an important role in preventing flooding downstream, as well as providing homes for wildlife

Early on New Year’s morning 2020, mizzle fell on Chimney Meadows, but, after the last flock of conservation grazing sheep was fed, in a blink of an eye the sky cleared and the first rays of sun broke through. The warmth was deliciously discernible and the sudden light captivating.

Witnessing the first appearance of the sun felt like a symbolic moment, bringing a sense of hope and promise for the new year ahead – a moment in time worth cherishing.

Of course, the wet weather which dominated much of the later months of 2019 has continued, if not stepped up a notch, into January and February. Persistent drizzle, sudden squalls and prolonged periods of bucketing rain have gradually led to puddles becoming pools and temporary lakes forming a vast watery landscape.

Raindrops

Ditches have filled, water tinkering at the edges, creeping over, seeping through the vegetation, tentative at first, like an advance party, and then, a route found, confidently pushing forward.

The interpretation boards at Chimney Meadows tell us that the place name originally meant Ceomma’s Island, suggesting that the surrounding land was often submerged.

The meadows provide a natural floodplain for the Upper Thames and, with the nature reserve being on a floodplain, winter flooding is expected.

Chimney Meadows plays an important role in holding water back from entering the Thames and helps prevent flooding downstream.

Duxford Old River

Lapwing, golden plover and gulls on the flooded land at Duxford Old River by Louise King

Management of the reserve over the years has encouraged this wetland habitat, for example through the creation of scrapes, seasonal ponds and channels. This habitat supports a diverse range of plants, insects and birds.

Indeed, this winter, BBOWT surveyors have counted phenomenal numbers of gulls, geese and waders. Seeing these visiting birds on mass gathered at the water’s edge during rare interludes of sun, hearing the distant tinkling of teal, and watching lapwing and golden plover rise and swoop in kaleidoscope swirls is a wonderful experience.

What’s been fascinating is how the birds regularly change their feeding locations in response to the fluctuating floodwater levels across the reserve.

One of the perks of volunteering as a stock watcher for BBOWT is being treated to special encounters with nature. Stood among the cows this morning, a barn owl hovered nearby and then flew so close the sound of its wing beats were audible. At this time of year they are pairing up. Their main food source of field voles and wood mice, despite all the habitat piles our volunteers have made, is likely to have fared badly in the flooding.

Barn owl in field

Barn owl in field. Photo by Jon Hawkins Surrey Hills Photography

While it is always a thrill to see a barn owl, spotting them out hunting in daylight hours is a bit of a concern. To survive and breed successfully they must intensify their hunting efforts.  

The mammals at Chimney Meadows must also adapt to the wet conditions. Badger setts have filled with water and these nocturnal creatures, whose cubs are born around February, have been excavating new burrows. Brown hares, always living entirely in the open rather than underground, are having to find drier spots away from the waterlogged ground where they can hunker down undisturbed.

There have been recent local reports of otter fatalities on the roads. Perhaps, conditions have pushed them into being more active, onto different routes or into new territory. Investigating some fresh, jasmine-scented otter spraint, made up of tiny bones and fish scales and placed prominently on a log today was a distraction from counting sheep and a pleasing indication of an otter’s presence.

Chimney Meadows

Wild flowers at Chimney Meadows by Andy Fairbairn

It’s hard to picture how the hay meadows, after this prolonged period of being awash, will be filled with colourful wild flowers, insects and butterflies come June. However, over the years, the traditional methods of hay cutting, winter grazing and nature’s seasonal patterns have combined to create the conditions for an amazing transformation of the landscape as the year unfolds.