For the following reasons:

Ecology

  • The Mimram is a chalk stream, beginning near Whitwell and ending at Hertford, where it joins the River Lea.
  • Chalk streams are rare and special.  They are spring-fed rivers originating from chalk bedrock aquifers.
  • They are known for their crystal-clear, mineral-rich, consistently cool water, and gravel beds that support unique wildlife.
  • These ecosystems are vital for biodiversity, supporting species such as brown trout, water voles, and kingfishers.
  • Within the valley boundary that we have defined, are:
    • 1 Site of Special Scientific Interest (with one more just outside);
    • 5 Local Nature Reserves;
    • over 70 Local Wildlife Sites (with many more just outside).

Landscape

  • The valley landscape has virtually no recent major modern building, and no evidence of heavy industry; only the numerous old mills dotting the river’s course.
  • The valley is largely pollution-free.
  • The valley hosts a number of arable farms and areas of ancient woodland.

Heritage

  • Numerous settlements and areas along the length of the valley (or adjacent) are mentioned in Domesday Book (e.g.:King’s Walden, St Paul’s Walden, Bendish, Kimpton, Knebworth, Codicote, Welwyn, Ayot St Lawrence, Ayot St Peter, Digswell, Tewin, Hertingfordbury and Hertford).
  • Within the valley boundary are some 270 designated heritage assets (listed structures), ranging from the iconic Digswell viaduct, to the shop fronts and pubs on the High Streets of Welwyn and Whitwell (which include examples from the mediaeval through the Georgian to the late Victorian period).
  • Several long-standing churches (and churchyards) at Hertingfordbury, Tewin, Welwyn, Ayot St Peter, Ayot St Lawrence (Old and New!), St Paul’s Walden and Kings Walden.
  • Also, distributed along the valley are:
    • 5 registered and a further 9 unregistered (usually historic) parks or gardens.
    • 5 ancient monuments (perhaps most notably the Welwyn Roman Baths and adjacent villa complex);
    • The conservation areas of Hertford, Hertingfordbury, Tewin, Welwyn, The Ayots, Whitwell and Bendish.
    • There are many more listed structures just outside the area, notably in the conservation areas of Knebworth, Codicote and Kimpton.
    • Numerous old mills – both grain mills and fulling mills (for cloth).
  • The valley is particularly notable for the current and former large estates distributed along its length.
  • Some of the parklands in the Lower Mimram Valley were the result of work by Lancelot (“Capability”) Brown and Humphry Repton.  (Links are to Wikipedia pages).

Accessibility

  • There are views of the valley slopes, and the various parklands, country houses and villages, throughout its length.
  • It is possible to walk the length of the valley on public footpaths, with minor interruptions.
  • Creating a Mimram Valley Trail linking some of paths, to provide a signed walk along the valley’s length, is a future project that we expect to work on with some of our partners and in co-operation with the various landowners.  Subsequent publicity for the Trail will highlight the interesting places and buildings along the route, and encourage patronage of the numerous pubs, cafés and restaurants.
  • Access is facilitated by rail (The Great Northern Railway, with stations at Welwyn North and Knebworth) and by road (the Great North Road; the A1(M); the B1000 and B656 and a good network of minor roads running east-west, north oof Codicote).

Geography

  • The valley is twelve miles long and in the centre of Hertfordshire.
  • It is close to London as well as Hertford, Stevenage, Hatfield, Welwyn Garden City and Luton.