summary

 
©Crown Copyright. All rights reserved. Hertfordshire County Council, LA 076678, 2001

LOCATION

This area is situated south of Colney Heath, west of the A1(M) and includes the section of the Shenley Ridge east of the M25.

 
©Crown Copyright. All rights reserved. Hertfordshire County Council, LA 076678, 2001

LANDSCAPE CHARACTER

An area with strong historic continuity, combining parkland on the lower slopes with extensive woodlands on the slopes and crown of a pronounced ridge. Area of arable estate farmland to the south east.

KEY CHARACTERISTICS

• pastoral parkland with mature trees
• extensive woodland cover at Redwell Wood complex
• Elizabethan house set in ornamental grounds
• estate farmland associated with Home Farm

DISTINCTIVE FEATURES

• bridge over seasonal upper Colne
• swallowholes on ridge

North Mymms parkland (J. Billingsley)

assessment

PHYSICAL INFLUENCES

Geology and soils. The geology to the north of the area on the flatter vale comprises Aeolian silty drift and till, with a mix of deep stoneless well-drained silty soils over gravel (Hamble 2 series), and stoneless slowly permeable coarse loamy soils and silty soils over clay (Gresham series). On the elevated ridge the soils are slowly permeable and seasonally waterlogged with some brown subsoils (Windsor series) overlying Tertiary clay.

Topography. The northern area is gently undulating with a shallow valley to the upper River Colne. To the south west of the parkland the slopes rise significantly to the pronounced end of the Shenley Ridge, which has a number of secondary valleys.

Degree of slope. Less than 1 in 40 over the parkland and typically 1 in 14 on the wooded slopes.

Altitude range. 75-90m within the parkland and up to 30m on the wooded ridge.

Hydrology. There are a number of springs, streams and associated swallowholes on the wooded ridge. In the parkland there are a few ponds. The acidic Colne rises to the east as a seasonal overflow of the Mimmshall Brook, which disappears into a series of swallowholes near Water End. The Colne bed is normally dry through the parkland but there is a fine ornamental bridge at the park entrance.

Land cover and land use. The area comprises a mix of grazed parkland, woodland and arable. Within the parkland there are areas of ley and arable between woodland plantations.

Vegetation and wildlife. The natural woodland type on the acidic wet ridge is oak/hazel. To the south-east at Mymmshall Wood there is a transition towards hornbeam. Redwell Wood is an SSSI and a number of the other woods are ancient, including Cobs Ash and Hawkshead Wood. Species include ash, sycamore, field maple, holly, sweet chestnut and stands of conifers which include pine. Some of the woodlands are semi-natural with areas of wood-pasture origin and heath species in some of the woodland rides. Banks and ditches mark historic boundaries within the woods. Potwells, in the centre of the wood complex, is an area of secondary grassland, having been previously ploughed for set-aside. Within the parkland there are a number of fine mature oaks, and an avenue of lime trees more closely related to the house. Most of the boundaries of the park are marked by timber and stock-proof fencing. Where present, hedges tend to be hawthorn, elder and elm with individual field oaks.

HISTORICAL AND CULTURAL INFLUENCES

There is a strong sense of historical continuity. North Mymms Park was recorded as a medieval deer park as late as 1766. The area extended up the slopes to the woods.

Field pattern. The arable area to the south east associated with Home Farm comprises mainly pre-18th century organic enclosure with some larger prairie fields which have been created since 1950. Fields are medium to large. The parkland is open with occasional wire fencing.

Transport pattern. The park is bounded by Tollgate Road to the north east. Elsewhere there are no public roads but a number of estate and woodland tracks.

Settlements and built form. The settlement pattern is dominated by the estate. North Mymms House is an 'H' plan Elizabethan house, set in the grounds of the medieval deer park. The main gardens were designed by Sir Ernest George in the 1890s, while the rose garden and pergola garden were designed by the influential Victorian garden designer, William Robinson. Other estate properties include Home Farm and the parish church of St Mary, around which there is a cluster of traditional properties. Within Redwell Wood isolated foresters' lodges have developed, e.g. Oak Lodge.

OTHER SOURCES OF AREA-SPECIFIC INFORMATION

English Nature SSSI notification.

Pevsner, N., rev. Cherry, B., Hertfordshire, Penguin (2000).

evaluation

VISUAL AND SENSORY PERCEPTION

The woods are a prominent feature in this landscape, cloaking the horizon of the elevated ridge. The parkland is more locally visible, particularly from Tollgate Road where there are some longer views through to the more open Vale of St Albans to the west. This is a largely contained area, with the most open aspects to the north and on the lower arable slopes to the east. Ancient woodland and plantations frame views, and in places provide a sense of confinement. Despite the visual continuity of the vegetation and strength of landform the area is adversely affected by noise from the M25 and A1(M).

Rarity and distinctiveness. The combination of grazed parkland and extensive woodlands is rare in the county

VISUAL IMPACT

There are a number of detracting features within the landscape, of which the adjacent motorways are perhaps the most significant.

ACCESSIBILITY

There are few rights of way across the parkland. However there are a number of routes including bridleways up to and through the Redwell Woods complex. These become wet and muddy after rain.

COMMUNITY VIEWS

These are valued and distinctive parkland and woodland landscapes (C).

LANDSCAPE RELATED DESIGNATIONS

SSSI Redwell Woods.

Watling Chase Community Forest.

 

CONDITION
Land cover change:	insignificant
Age structure of tree cover:	mixed
Extent of semi-natural habitat survival:	widespread
Management of semi-natural habitat:	variable
Survival of cultural pattern:	intact
Impact of built development:	low
Impact of land-use change:	low
ROBUSTNESS
Impact of landform:	prominent
Impact of land cover:	prominent
Impact of historic pattern:	continuous
Visibility from outside:	locally visible
Sense of enclosure:	partial
Visual unity:	coherent
Distinctiveness/rarity:	unusual

guidelines

STRATEGY AND GUIDELINES FOR MANAGING CHANGE: IMPROVE AND CONSERVE

• prepare and implement a conservation and restoration plan for the historic parkland. Scheme to fully address landscape, historic and ecological issues
• restore historically appropriate and high-quality boundaries to parkland, e.g. metal estate railings
• promote recording and management of veteran trees for biodiversity value and visual amenity
• encourage new planting to maintain structural and age diversity of the parkland trees. Landscape improvements should respect the historic context of existing features and the form and character of the parkland and gardens. Ornamental species should only be used to replace damaged or over-mature specimens, where appropriate
• within parklands, encourage the reversion from arable to pasture
• restrict ploughing of grasslands within parklands
• encourage landowners to retain and increase ponds and wetland areas to enhance their visual and wildlife functions
• encourage appropriate management measures to benefit the upper reaches of the Colne
• promote hedgerow restoration and creation throughout the arable areas to provide visual and ecological links between existing and proposed woodland and parkland areas. Pattern to follow historic field boundaries where possible
• promote the creation of buffer zones between intensive arable production and important semi-natural habitats and the creation of links between semi-natural habitats
• support the Watling Chase Community Forest in the realisation of its objectives for the area
• promote appropriate woodland management for existing woodlands, including the replacement of softwoods with indigenous native deciduous communities and hedgebank management
• ensure that a wooded skyline is preserved
• promote the appropriate management of coppice woodland in order to re-establish a rich ground flora and the distinction between different management systems, such as high forest, coppice, coppice-with-standards and wood pasture
• promote the expansion of woodland beyond ancient woodland boundaries, especially where this will help in creating habitat links and will not disturb historic features or valuable wildlife habitats
• establish realistic and attractive countryside management schemes for sites with heathland and acid grassland communities
• review public access arrangements to woodlands and parkland including low-key but enhanced car parks
• maintain local patterns of species diversity within woodlands
• promote the continued use of stock grazing as the preferred management for the parkland
• promote crop diversification and the retention/restoration of mixed livestock/arable farming
• ensure a strong presumption against development within or adjacent to the area and in particular that which could lower the water table within river valleys and affect wetland habitats
• establish tree-planting measures to minimise the impact of the M25 and A1(M)

Redwell Wood from the south (J. Billingsley)