A river runs through it
PUBLISHED: 09:48 10 February 2015 | UPDATED: 09:48 10 February 2015
Restoration work on the important River Purwell in Hitchin is helping to bring back iconic species, Countryside Management Service projects officer Zoe Channon gives a guide
The Countryside Management Service has been focusing efforts on chalk river restoration in and around Hitchin, particularly on Purwell Meadows and Walsworth Common. The group has been working with the landowner, North Hertfordshire District Council, to undertake several elements of restoration on the River Purwell, which links the two sites.
Chalk rivers are globally rare. There are only about 200 in the world, most of which flow in the south east of the UK. They rise from underground aquifers lying deep in chalk, meaning their waters are alkaline with an even temperature that flow swiftly over gravel beds. Because of these unique conditions, they house a specific set of flora and fauna including iconic species such as water vole, brown trout, water crowfoot and kingfishers, to name but a few.
Over time, it’s common to find that rivers have been modified or moved, often to make space for recreation, landfill or roads. Modification has caused rivers to become canalised and wide, losing their vegetated banks and in turn causing the river flow to slow down and for silt to build up. All over the country, chalk rivers are losing their characteristics and attractive features and, more importantly, losing their associated wildlife, meaning action needs to be taken.
Purwell Meadows and Walsworth Common are popular spots for visitors who enjoy the combination of a peaceful relaxing meadow with a river meandering through and fun recreational areas for children. Joining both commons is the River Purwell, which starts its life at springs that rise up from the chalk bedrock in the nearby village of St Ippolyts before flowing down Ippolyts Brook to form the River Purwell. Eventually it joins the River Hiz downstream at Walsworth.
Improving the environment
Various restoration activities have taken place along the length of the river Purwell from Purwell Meadows to Walsworth Common. At Purwell, focus has been placed on riverbank restoration, in particular to provide a suitable habitat for water voles who like to burrow into the riverbank.
Alongside this river work, wetland enhancement has taken place with the creation of scrapes (shallow depressions with gently sloped edges that seasonally hold water), which support a variety of invertebrates and are important feeding areas for wading birds such as snipe and little egret.
At Walsworth Common, the focus has been around reducing the width of the river. Flow deflectors made out of logs and brush are pinned to the river bed using chestnut stakes. These have been installed by CMS and Environment Agency volunteers to help reduce the width of the river and thereby speed up and create diversity of flow. Increased flow flushes away silt and scours out channels, ensuring deeper, narrower channels in summer and autumn when water levels are low. This will ensure river levels are still high enough to allow the movement of fish and invertebrates. The characteristic gravel bed is now returning, which is the spawning ground for many trout and other fish species, so things are looking up.
If you visit in summer, look out for grey wagtail with their characteristic lemon yellow under-tail foraging in the faster running parts of the river for mayflies, water beetles and water snails. It’s a fine sight.
Visiting the River Purwell
Purwell Meadows Local Nature Reserve is in the heart of Hitchin on Purwell Lane. The site is a complex of grazed pasture, marsh, wet grassland, scrub, hedgerows and trees alongside the River Purwell. A leaflet which gives a helpful overview of the greenspace, along with a suggested walk, can be downloaded from hertslink.org/cms/getactive/placestovisit/purwellmeadows
Situated on the Purwell Valley floodplain in the north east of Hitchin, Walsworth Common on Woolgrove Road has a car park and numerous opportunities for play, recreation and sport, such as a children’s playground, football pitches, a basketball court and skateboard ramps.
The common is an important link in the local sustainable transport network. Walkers can venture out of town south along the Purwell valley towards St Ippolyts and Little Wymondley via Purwell Meadows and Purwell Ninesprings or can gain access to the north and the rivers Hiz and Oughton via the Hitchin Outer Orbital Path and the Hicca Way.
More information and a link to the Hitchin Outer Orbital Path can be found at hertslink.org/cms/getactive/placestovisit/walscomm