The Chess Valley Walk reaches from Chesham down to Rickmansworth, a distance of approx 9 miles. Following the meandering line of the river Chess it runs through some of the Chilterns most stunning scenery – here we feature the section from Chenies Mill Farm to Sarratt Bottom that also includes the Frogmore Meadow Wildlife Trust Nature Reserve.
Mill Farm Water Meadows
Chalk streams are fed here by mineral rich springs which leave the ground at a constant temperature of up to 10 C. In winter the meadows in front are flooded, the water level being controlled by a system of ditches and sluices. This helps to warm and fertilize the soil, promoting the early growth of grass in the spring. The low bank across the field to the left may have been created to retain the flood water.
Cattle graze from early spring to autumn, helping to create ideal conditions at Sarratt bottom just downstream from here; you can see how this habitat is rich in birds, plants & flowers. In Summer Marsh Marigolds can be found blooming all along the banks of the Chess.
About Frogmore Meadow
Flower and insect-rich water meadows like this are now rare in Hertfordshire and nationally. Untouched by modern agriculture Frogmore Meadow has probably remained the same for hundreds of years. No chemical fertilisers or pesticides have even been used here, so that many uncommon plants including grasses and sedges have survived - Lots of Life in a little site!
In summer, the meadow is alive with butterflies, grasshoppers and dragonflies and in the winter, Fieldfare Redwing and little Egrets may be seen.
Frogmore Meadow is cared for by the Wildlife Trust.
Volunteers always welcome – call on 01727 858901
Watercress Beds
 
The clean, warm water of the Chess creates ideal growing conditions for watercress, once a common crop along the river but now grown only here at Sarratt.
Water from the Chess is diverted into a series of growing compartments – “beds”. The cress takes root in the shallow beds, taking minerals from then calcium rich water. The flow is added to by spring water from deep in the aquifer which is at a constant temp of 10 C. In years when the air temp remains high enough the warm water allows cultivation throughout the winter.
The beds support some interesting wildlife, notably the elusive and secretive water rail which benefits from the warm water, particularly in Winter. Buying local watercress helps to keep this environmentally friendly industry alive. The watercress beds are open daily (and usually on Saturday mornings) for customers to buy local and great value produce.
Sarratt Bottom & “Lynchets”
 
The eastern slope of the valley here is dominated by the “Lynchets” ancient terraced field systems thought to date from the 9th Century. Here on flat areas of the terracing wheat and barley was grown. Between the 9th and 13th Centuries when the climate in the Chilterns was much warmer, local wine may have been produced from vineyards which are thought to have been cultivated here.
The water meadows opposite need regular grazing by cattle in order to create ideal conditions for wildlife. Only with appropriate grazing and management of the water levels can wet land- loving birds such as Snipe, Water Rail and Redshanks find food and shelter here. The diversity of plant and food in the meadows also increases if they are grazed. Without this management, meadows such as this become dominated by woody plants and coarse grasses and then wildlife diminishes.
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