Environmental Engineering Reference
In-Depth Information
Birds recorded along the rivers and streams include grey wagtail Motacilla cinerea , grey heron Ardea
cinerea andkingfisher Alcedo atthis ,althoughthelatterisascarcebirdinGower.Dippers Cinclus cinclus
have also been recorded on the Clyne River and Pennard Pill.
OXWICH MARSH
The origin of the marsh goes back some 2,500 years, to when the sea deposited a shingle ridge across the
westernendofOxwichBay.Dunesgraduallyformedontheridgeastheonshorewindsblewinthedrying
sand from the beach at low tide, a process that is still occurring today, though at a much reduced rate. The
lagoon trapped behind the dunes eventually silted up with sand blown inland, and this led to the creation
of freshwater and salt marshes. By the twelfth century the salt marsh and dune meadows had sufficient
grazing value to be shared by the manors of Oxwich, Penrice, Nicholaston and, even though it lay some
distance away, Horton. This grazing was important because of the shortage of meadow land for fattening
stock and providing winter hay, and the hayward, who supervised the grazing, ensured that the dunes re-
mained stable. The fact that the marsh was originally salt marsh is confirmed by a warrant issued in 1694
by Sir Edward Mansel of Margam to Thomas Vosse, which appointed Vosse as his water-bailiff 'within
the Port of Oxwich and creeks within the Bay of Oxwich'.
The common reed was frequently used for thatching cottages, and a number of such cottages still ex-
isted in the early 1900s, though all these have now been reroofed, mostly with slate. Only a few cottages
with straw thatch survive today, one of them, Margaret's Cottage in Oxwich village, situated close to the
reedbed that may have supplied its first roof. Although the reedbed in its current form is only 70 or 80
years old, and even though there were small reedbeds in places before this date, the reeds might not have
been of roofing quality (Fig. 130).
Two hundred years ago the current freshwater marsh was mainly salt marsh, and the sea was able to
flow around the end of the dunes to flood the low-lying land almost as far as the village. Most of the salt
marsh was reclaimed from the sea by Thomas Mansel Talbot, then owner of Penrice Estate, at the end
of the eighteenth century. As early as 1769 he was contemplating 'erecting a Sea Wall or Bank across
NicholastonPilltopreventtheflowingoftheSeaonhighSpringTidesoverOxwichMarshsoastomake
it of greater Value by the Acre than what it is at present' (Davies, 1814). In earlier periods drifting sand
had blocked some of the creeks and the return of stormy conditions in the seventeenth century led to the
rate of siltation increasing, which prompted Talbot to take action. Around 1794 he instigated a series of
works that included digging a ditch around the perimeter of the marsh to contain spring and stream wa-
ter, together with a series of internal drainage ditches. He then excavated a meandering ornamental lake
runningthe length ofthe marsh, twosmaller pondsinPenrice Parkandanextensive ditch system todrain
away the fresh water flowing into the marsh from the numerous small streams and springs along the old
cliffline. The land was gradually converted to rough pasture, dissected by drainage channels, which was
mostly used for cattle grazing. Walter Davies was highly enthusiastic about the success of the operation
from an agricultural viewpoint 'Before the tides were excluded, the marsh afforded healthy pasturage for
sheep but it is now quite the reverse … it has now become excellent pasturage for cattle and horses.'
The system worked very well, the vegetation changing from salt marsh to pasture, and for about the next
hundred years provided rich grazing for cattle, though not without cost. Three men had to be employed
throughoutthesummertokeeptheditchesclear,andtheseawallandsluiceneededregularattention.The
channel below the sluice also had to be dredged out each winter using a horse-drawn wooden plough.
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