Public access and reserves
Archers Green
In September 2023, Herts and Middlesex Wildlife Trust secured a philanthropic loan to purchase Archers Green, a new nature reserve with flower-rich meadows, flanking the beautiful River Mimram. Archers Green sits in the Mimram Valley, near the village of Tewin in Hertfordshire, within a priority area for conservation action. It includes priority habitats, identified in Hertfordshire’s State of Nature report – lowland meadows, wet woodland, marsh and a chalk river – all of which support a great range of rare plants and animals. Such is the importance of Archers Green, that it has been designated as a Local Wildlife Site. Sadly, these habitats have been declining over recent decades and with them so have the species that call them home. Archers Green is on the route of the Hertfordshire Chain Walk. Whilst public access to the site itself is restricted to protect the sensitivity of the site and to allow conservation management, you can experience the sights and sounds from the public footpath and, in particular, the vantage point of the old stone bridge, which spans the Mimram and forms part of the route. Find out more about the route of the Hertfordshire Chain Walk here.
Singler’s Marsh
Singler's Marsh is a Local Nature Reserve just outside the village of Welwyn. The river runs through lowland flood meadows, a rare habitat in Hertfordshire. The underlying chalk rock and damp conditions support a range of specialist plants, such as meadow saxifrage, meadow sweet, bistort and sedges. Specialised grazing and mowing regimes allow these plants to flourish. The river itself is an important resource for insects and birds, and various species of willow also grow on the marsh.
The site is owned by Welwyn Hatfield Borough Council. Volunteers from the Friends of the Mimram Singlers Marsh Special Interest Group ensure that footpaths through the reserve are maintained, and also regularly carry out habitat enhancement work.
Parking is limited, but some roadside parking is available. Access points are found on the south, west and north sides of the marsh.
Tewinbury SSSI
Adjacent to the Mimram, Tewinbury is a Site of Special Scientific Interest and a Herts & Middlesex Wildlife Trust reserve. It is one of the best places in the Mimram valley for wildlife. Habitats include reedbed, swamp, fen, wet woodland and wet meadows. As well as supporting a range of different plants, this variation in habitat make it a fantastic place for birds. In winter, reed buntings, yellowhammer and pied wagtail form night-time roosts, and siskins and redpolls feed in the woodland. In spring and summer, breeding species include reed bunting, reed warbler, sedge warbler and occasionally grasshopper warbler. Mallard, coot, and moorhen also breed. Other species of note include kingfisher, water rail, snipe and woodcock, and many migrating warblers. Otters have also visited here in the past.
Although access to the site itself is restricted, there is two-storey hide at the south side of the reserve, accessed via the lane to Tewin Bury Farm Hotel. It gives fantastic views down into the reedbeds and is also one of the best sites in the county for spotting water voles. The lower storey of the hide is fully accessible, and with nearby parking (thanks to the Tewinbury Hall Hotel) it can now provide wildlife watching opportunities for visitors of all abilities. You can also access the river itself through the reserve just downstream from the hotel. (The gate is at the bottom of the carpark)
Find out more here.
Panshanger Park
Panshanger Park is a 1000 acre country park that was designed by Repton and the Mimram runs right the way through it. The park was closed in the early 80's for gravel extraction, but the agreement was that it would be restored as a county park with access for the public. The first 200 acres were opened in Spring 2014 and the strategy for how the remaining acres will be opened up is still being planned. Restoration is being co-ordinated through an advisory management committee which includes Herts and Middlesex Wildlife Trust, Herts County Council and the Environment Agency.
The Park contains a rich variety of wildlife habitats including ancient woodland, veteran trees, flower-rich and wet grasslands, fen and marsh, lakes and one of the best stretches of the River Mimram. Wildlife includes water voles, otters, many types of birds and bats.
Walks and guided walks are available. The entrance and car park is in Thieves Lane, Hertford, off the A414. Postcode: SG14 2WN
Public access
Footpaths
Public footpaths along the Mimram are limited, as the river mainly flows through private land. However, a public footpath does run alongside or near to the upper river, between Codicote Bottom and Rye End Cottages.