Liz Hamilton of Herts Campaign to Protect Rural England continues her inspiring route following the river Lea on the Lea Valley Walk

Great British Life: Lemsford Mill, its waterwheel generates electricity (Photo: Liz Hamilton)Lemsford Mill, its waterwheel generates electricity (Photo: Liz Hamilton) (Image: liz hamilton)

On a bright morning in early May I returned to Lemsford to resume my route down the River Lea, following the Lea Valley Walk. Warmer weather had finally arrived and the trees were bursting into blossom and leaf. Before setting off I stopped at Lemsford Mill to admire its facade and listen to the steady sound of the mill wheel turning. The mill building was converted into offices in 2005 and as a very practival and green part of the refurbishment a new waterwheel was installed which generates electricity for the offices and also feeds into the National Grid.

Hertfordshire’s rivers once powered dozens of mills. Many produced flour but others used the power for other purposes including fulling (a process to finish woven cloth), saw milling, silk throwing and papermaking. Sele Mill on the River Beane near Hertford was the first British mill to produce paper for printing, probably from 1491, although later the focus of this industry shifted to rivers in the west of the county. Today only a few watermills in the county remain in working order.

Below Lemsford the path crosses a short stretch of peaceful pasture alongside the Lea, before crossing the old Great North Road and passing beside the river under the modern A1(M). I wondered how many of the drivers rushing along the motorway above my head were aware of the river beneath them. Beyond the road I emerged into the parkland surrounding Stanborough Lakes. The two lakes here, with the river running alongside, provide for watersports, fishing and birdwatching and on the day of my visit many people were out enjoying the spring sunshine. Construction of the lakes on former gravel workings began in 1969 as an amenity on the southern edge of Welwyn Garden City and today the paths around the lakes and beside the river are ideal for families, including those with pushchairs and wheelchairs.

The lakes offer opportunities to get close to the birds that live on or beside water. Many species I saw were either nesting or escorting young families. Canada geese, with their black necks and distinctive white chin stripes, were keeping a close watch on their adventurous lime-green goslings. And as well as mallard ducklings, there were young moorhens and coot families. Adult coots are dark grey and black apart from a white forehead and beak, but their young outlandish chicks have bright red heads surrounded by yellow fluff.

Great British Life: Coot chicks - not quite as elegant as mum (Thinkstock)Coot chicks - not quite as elegant as mum (Thinkstock) (Image: thinkstock)

Further on, I caught sight of the distinctive bobbing action of two grey wagtails, quite common waterside birds, and later watched a great-crested grebe on its nest of twigs and old stems just above the water. A short detour from the lakeside path took me into the Stanborough Reedmarsh, a Herts and Middlesex Wildlife Trust reserve based around one of the county’s largest reedbeds. In this peaceful spot I encountered a grey heron standing perfectly still beside the river, until as I came closer it quietly lifted its wings and flapped away.

Beyond the end of the southern lake the path leaves the park and heads under a railway line, then crosses open farmland. From woodland to my left a family of four buzzards flew out to greet me with their mewing calls. After a few minutes of roadside walking I rejoined the river bank, beside the watermill at Mill Green.

Like Lemsford Mill, the mill here stopped producing flour in the early years of the 20th century. The building then lay empty and neglected until its new lease of life started in 1973, when restoration of the mill and mill buildings began. Today, the mill is in full working order and mills flour every week, alongside the local history museum housed in the adjacent buildings. Formerly known as Hatfield Mill, it was once essential to the economy of the Hatfield Estate and is located a short step from the Hatfield House park. Now, sadly, mill and park are separated by the busy A414 dual carriageway. Inside, the milling machinery is the main attraction, arranged over three storeys and especially fascinating when operating.

As I sat in the carefully-tended garden in front of the mill, I thought about the two working mills I had seen at each end of my three-mile walk, and wondered whether more could be made of the water power potential contained in Hertfordshire’s many rivers.

Great British Life: Grey heron are a stirring sight on the riverGrey heron are a stirring sight on the river (Image: thinkstock)

Beyond Mill Green the official route of the Lea Valley Walk turns away from the river, skirting the edge of Welwyn Garden City to join Cole Green Way, a disused railway line. Below the mill the river slips under the main road, to emerge in Hatfield Park. The river here was dammed to power a watermill which stood on the eastern edge of the park. Once a corn mill, it later became a saw mill and from 1881 housed a dynamo which supplied electricity to Hatfield House. Take the blue or red route in Hatfield Park (admission charges apply) to reach the lovely Broadwater, the lake created behind the dam and stop to take in the ever-changing life of the Lea.

Take the Lea Valley Walk

Map: Ordnance Survey Explorer map (1:25,000 scale) 182 covers the walk described.

Book: The Lea Valley Walk, by Leigh Hatts, third edition 2015, Cicerone Press.

Mill Green Museum: https://millgreenmuseum.wordpress.com/visitor-information for opening and milling times.