The River Mimram is one of our precious chalk streams. By one count, there are only 210 in the world, 160 of them in England, including many of the familiar streams of Hertfordshire.
The name is ancient and its origin unclear, certainly pre-Roman. In the recent past it has has several iterations. Only a dozen or so miles in length, the Mimram rises in Lilley Bottom and meets the Lea at Hertford. Along those few miles it hosts a wealth of bird life – kingfishers, egrets, herons and warblers below, kites, buzzards, and kestrels above. The lakes that draw from it attract dabchicks, teal, tufted ducks and pochard. Where it runs over gravel, you can spot brown trout. For the most part, I have not attempted to photograph the wildlife – I can’t do it justice. I started counting the tree species along or near the banks but gave up. All this is threatened by over-extraction and climate change.
With all these charms of nature, you might imagine the river to be as it was before The Fall. Far from it. The Mimram was – and, to some extent, still is – a working river, exploited, divided, re-routed over the centuries. In his excellent book River Mimram (Amberley, 2014), Tony Rook identifies the sites of 12 water mills along the course, each requiring the engineering of a mill stream, a chase and a pond. Fish ponds have drawn from the river from medieval times and water cress farms flourished in its pure water flow. Recently, the Panshanger stretch was exploited for gravel extraction. In the 18th and 19th centuries, wealthy landowners built a string of mansions along the high ground between Welwyn and Hertford, bringing in landscape gardeners who created new lakes and other ‘features’, including an artificial cataract below Tewin. The big houses needed water and this was supplied by creating weirs to drive pumps to carry it up the valley side.
Today, former mills are desirable residences, the big houses demolished or repurposed. The water cress farms are expiring and the gravel working has finished. But the Mimram still contributes to the local economy. Cattle and sheep graze in the water meadows. The water company extracts more than is sustainable. There’s a fish farm below Tewin. Anglers pay good money to fish for trout at Archers Green. At least one pub and one hotel gain custom from being riverside. And the benefits of walking or running in the vast Panshanger park keep the bill for health services down.
As with my series on Hertfordshire Greens, I haven’t tried to provide a comprehensive, documentary survey of the Mimram. I’ve walked the accessible stretches and I’ve taken photographs of subjects that caught my eye, be that a landscape, a stand of trees, the flow of the stream, or a reminder of our social and economic heritage. I hope you like the photographs.
The Mimram is a treasure. Friends of the Mimram works to protect it. The Chalk Aquifer Alliance brings together groups from around the country protecting chalk streams.
I will resume publishing posts on Wood, Structure, and Churches shortly.
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