Babbling brook attracts wildlife after restoration

A NEW “magical” wetland has been created next to Hamble Brook in Hambleden.

The 2,500 sq m site forms part of ongoing work by the Chilterns Conservation Board’s Chilterns Chalk Stream Project to restore the stream to a more natural state.

The project has reinstated natural wiggles in the channel, created new backwaters, removed embankments and planted trees to help with temperature control.

This has helped restore the natural character of the stream and better connect it to its landscape.

Hamble Brook is a rare, winterborne chalk stream that flows periodically.

It is sometimes dry along its entire length but currently benefits from high groundwater and is flowing from Turville to Mill End, where it joins the River Thames at Hambleden Lock.

Wetlands and meanders provide refuges for threatened native plants, insects, fish and mammals.

So far more than 1km of the Hamble Brook has been naturalised, taking in two former swimming sites, two ponds and 150m of connecting channel.

Three landowners have joined forces to complete the project with the help of the Environment Agency with support from the National Trust and funding from the Green Recovery Challenge Fund.

They include Maria Spink, of Colstrope Farm in Hambleden.

She said: “We bought the farmland back in 2020 and walking round the fields and seeing the brook for the very first time, it was clear that it had been man-made and pushed into a straight channel at one side of our fields.

“We later learnt that this had happened probably 140 years ago to create more space for farming.

“Its natural function and ecology suffered the ill-effects of the channel straightening and agricultural pollution, like so many watercourses.

“I was keen to create a tiny nature reserve [or] wildlife corridor along the Hamble Brook to give back its own original eco-system and ‘voice’ by rejigging and rejuvenating it.”

In 2020 Mrs Spink contacted Allen Beechey, head of the Chiltern Chalk Stream Project, and made enquires with the neighbouring landowners to take the project further.

In early 2021, with funding from the project, the work to rejuvenate more than 1km of the brook began. Mrs Spink said: “The change in the landscape has been fantastic. It has become a magical place where you can hear the brook singing and bubbling along.

“Water birds have arrived this spring and some very special water insects have returned.

“The amazing thing is that the Hamble Brook is a winterborne chalk stream so it normally only runs when the groundwater is high.

“Because these are temporary and dry up at times, it creates unique conditions along with the chalk bedrock and supports an unusual diversity of wildlife with many specialist insect species.

“Because chalk is rare worldwide, there are very few winterborne chalk streams globally.

“We have a very rare precious asset that we need to be good custodians of.

“The Environment Agency and National Trust have been very supportive and all three landowners contributed to the funding of the project.

“The project started just over a year ago, so it is amazing to see how quickly nature has bounced back.”

Mrs Spink said the aim was to allow the brook to run as it would have done before it was dug up and redirected into its straight jacket of the channel.

Using light detection and ranging maps, a remote sensing technology used to acquire elevation data about the earth’s surface, they were able to see where the brook had meandered before. Mrs Spink said: “The idea was to renaturalise these areas along the brook to allow the water to go where it wants to go and to improve the connectivity of the brook with the landscape it sits in.

“From special LIDAR maps we could see where the brook had meandered before and to recreate these tributaries, a digger shallowly scraped out the fields into lower areas where streams have now sprung up, creating the wetland mosaic you can see today.”

She hopes more landowners and custodians of the brook will join the project.

Mrs Spink said: “I love seeing the stream run as it is supposed to in its current shape.

“It makes one realise how little needs to be done to help nature reinstate itself and come back with all the habitats that used to be here.

“It would be amazing if we can get fish back in the stream. as I was told used to happen not that long ago.”

Charles Hussey, a Hambleden parish councillor and retired member of the scientific staff at the Natural History Museum, has been involved with the project from the start.

He and his wife Kate have been testing the wildlife in the brook since 2021 in partnership with the Environment Agency.

He said: “It was a scheme that was aimed initially at anglers where anyone could come and be trained to identify eight different groups of invertebrates.

“The survey involves going into the stream and doing a kick sample and count, which is a timed sample and recognised by the Environment Agency.

The agency sets a trigger level and if the count falls below that it will investigate because that would mean there is potential for pollution in the stream.

“Walkers will like to see the bubbling brook when it is in flow but below the surface it is absolutely teeming with life and it is in a pretty good condition.

“There are currently three landowners engaged with this project and if we can get more upstream and downstream much more can be done.”

Adrian Porter, rivers officer at the Chilterns National Landscape, said: “Working with the natural undulations of the landscape, we created lowered areas which will be wetter for longer, providing a valuable habitat for plants, birds, insects and small mammals.”

Pippa Tucker, catchment co-ordinator at the Environment Agency, said: “Chalk streams are globally rare and fragile habitats that require sensitive management.

“We were delighted to be able to carry out this important piece of work and it’s fantastic to see the site already showing significant promise.

“It’s a great example of what can be achieved through a successful partnership and we hope this will pave the way for similar restoration projects along the brook and throughout the wider Chilterns landscape.”