Environmental Engineering Reference
In-Depth Information
Therearetwomaintypesofstandingwaterbodies,eutrophicwatersandmesotrophicwaters,andboth
occur in Gower. Of the six largest bodies two are eutrophic and four mesotrophic. Eutrophic waters are
highly productive because plant nutrients are plentiful, either naturally or as a result of artificial enrich-
ment. Planktonic algae and zooplankton are abundant in the water column and the submerged vegetation
is diverse, with numerous species of invertebrates and fish. There is often a marginal fringe of reeds,
which is an important component of the aquatic ecosystem. Bottom-dwelling invertebrates such as snails,
dragonfliesandwaterbeetlesarealsoabundant.Incontrastmesotrophicwaterbodieshaveanarrowrange
of nutrients, but contain a higher proportion of nationally scarce and rare aquatic plants. Invertebrates are
particularly common, with important groups such as dragonflies, water beetles, stoneflies and mayflies
present.
According to the current Ordnance Survey map of Gower there are, or were, some seventy-five farm-
yard and field ponds, many near to or adjoining field boundaries, or tucked away in field corners. As
about one-third of these are shown as being very small, it is likely that many of these have been filled in
ornaturally silted upsince themapwassurveyed,probablyinthe1970s.Althoughpondsgradually fill in
with silt and debris and vegetation through natural succession it is best to maintain them in all stages of
succession, so that there are both new ponds and well-vegetated ones in the same area. Moreover, a num-
ber of medium-sized ponds seem to have almost completely disappeared. As a rough estimate therefore
about half of the ponds, fewer than forty, may survive. In addition to this total there are forty waterbodies
on common land and five ponds in woodlands.
BROAD POOL
BroadPoolisthelargestnaturalwaterbodyinthepeninsulaandoneofthebest-knownfeaturesincentral
Gower (Fig. 133). It was given to the Glamorgan Naturalists' Trust, as it was then, in May 1962 by the
Duke of Beaufort as the Trust's first nature reserve. Covering over a hectare, it is a very shallow pool,
less than 1.3 metres deep even at peak midwinter water level. The pool is situated on a flattish area of
limestone overlain with boulder clay and is surrounded by heath with bog-mosses in the wetter areas.
The earliest mention of Broad Pool is in an affidavit by John Long of 1 October 1705, showing that it
was a clear landmark at that date and suggesting that it had been so since the 1640s. The earliest map of
the area, an estate map of Walterston and Cilibion of 1785, shows Broad Pool clearly labelled as 'Cevan
y Brynn Pool', with the tenth milestone from Swansea beside it. This and all later maps show the pool
almostexactlythesamesizeandshapeitistoday.Ithasbeensuggestedthatthename'BroadPool'comes
from the name of the surrounding area, Broad Moor, and is not a reference to the size of the feature.
Whatever the origin of the name it is clear that the pool has been an important area of open water that has
existed for at least 400 years and has been maintained as such throughout this time.
