LCT5 River Valley Floor
General Description
The River Valley Floor landscape character type is a prominent feature of the Test Valley Borough landscape, linking many of the other landscapes. The river valleys which extend through the Test Valley fall into two principal categories; the wider flat bottomed valleys of the main river systems and the narrower valleys with steeper sides and which contain either tributaries of the main river system or bournes/winterbournes. The valleys are predominantly under pasture, with characteristic waterside tree species such as willow and alder running alongside individual watercourses and areas of meadow grassland, reedbeds, marshlands and other wetland habitats.
The settlement pattern originally consisting of mainly nucleated villages and hamlets, which since the 18th century have expanded along their approach roads to become more linear in form.
Location
This landscape character type includes the River Test runs into Southampton Water (divided into three reaches) and six of its tributaries (Pillhill Brook, River Anton, River Dever, Wallop Brook, King’s Somborne Brook and the River Dun). The River Valley Floor covers the valley bottom, with the valley sides lying within the adjacent landscape character types (predominantly LCTs 3 and 10). The transition is marked by river terraces along the River Test and a change in slope at the edge of the valley floor. The ten Landscape Character Areas are as follows:
LCA5B Middle Test Valley Floor
LCA5E King’s Somborne River Valley Floor
LCA5F Wallop Brook River Valley Floor
LCA5G River Dever Valley Floor
LCA5H Pillhill Brook Valley Floor
LCA5I Upper River Anton Valley Floor
LCA5J Lower River Anton Valley Floor
Physical Influences
Geology and Soils: The underlying geology consists of river deposits of alluvium with side areas of river terrace gravel deposits, deposited over the solid geology of chalk or sands, clays and gravels.
Landform: Valley with a flat flood plain of varying width.
Drainage: Characterized by a single channel or a multiple braided system of streams.
Biodiversity and Vegetation Pattern
The River Valley Floor is a characteristically flat low lying area this type is typically pastoral bordering the river, often with wet swampy areas. There are frequent copses dominated by Willow, Poplar and Alder and often river banks are fringed by standard trees. The hedgerows have a much looser structure than other farmland areas and more use is made of water meadow ditches as wet hedges. This type is one of the most ecologically diverse in the District with a variety of wetland habitats, unimproved grasslands and carr woodlands.
Notable habitats
Chalk streams
Unimproved calcareous grasslands
Semi-improved grasslands
Historical Influences
The river valleys have in recent times offered fertile and freely drained soils with access to a generally continuous supply of fresh water. However, throughout much of the prehistoric period the river valleys were often dominated by dense forests with movement only possible via either the ridge ways or along the river network. Little survives of early human activity which is often buried beneath considerable deposits of alluvium or destroyed by the continuous cutting and recutting of the river channel.
The most prominent feature throughout this landscape is the numerous surviving systems of post-medieval water meadows interspersed by stands of valley floor woodland, rough grazing and what are termed ‘miscellaneous valley floor enclosure’. The water meadows (reputedly developed by Rowland Vaughn in the later sixteenth century) were a system whereby the growing season could be extended and two crops of grass could be grown instead of a single one.
The water meadows fall into two distinct categories; bedwork and catchwork systems. The bedwork system (Types 2 and 4) are generally found in wide open valley floors where extensive blocks of water meadow could be constructed and supplied by a complex series of sluices, leats and drains. The catchwork system (Types 1 and 3) tended to occupy narrower valley floor and sides, were fed often by a single leat and relied on gravity to move the water to (and from) the fields. This pattern of bedworks on the River Test and catchworks on the tributaries is largely repeated throughout the Test Valley Borough.
Settlement Pattern
Chalk and Clay River Valley Settlement Types are predominantly associated with this landscape character area. The settlement types are generally linear in plan and are located upon valley floors as the focus of a network of valley floor and side roads. Smaller settlements tend to occupy a single riverbank while larger examples can span river channels to occupy both banks. Such settlements can often retain one or more bridges which are either medieval in date or are early medieval structures with medieval precursors. River valley settlements often retain a historic core of sixteenth and seventeenth century date and possibly building of an earlier date including early medieval churches and manorial complexes.
Communication Network
The principal feature of the communication network within the river valleys is that they tend to align themselves with the main channel and only cross infrequently at fording or bridging points. A series of main roads extend along the valley floor of the River Test with short spur roads extending at right angles to these main routes.
Key Natural and Cultural Landscape Issues
Maintenance of water quality and flows and prevention of further pollution of water bodies from diffuse pollution, run off and aqua culture ventures (fish farms, water cress beds)
Impact of development and increasing traffic within the valley floor leading to loss of remoteness and tranquillity
Increasing pressure for recreation
Loss of unimproved mesotrophic grassland to arable or through application of fertilisers
Scrub through changes in land management
Increased silt loading through erosion of previously permanent pasture
Manicured river banks for commercial fisheries causing loss of aquatic habitat
Further loss of original nucleated settlement form to linear development
Increased need for water abstraction leading to wet grasslands and woodlands drying out causing a reduction in biodiversity
Potential for increasing biodiversity through sensitive land management
Presence of expanses of historically significant early/late post-medieval water meadow earthworks. surviving within the valley floor.