Specialists in Water Management for Landscapes, Fisheries, Leisure and Conservation
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Case Study 6. Lake Restoration Work |
Client: The Royal Parks
Location: Bushy Park, Hampton
Description of Contract:
Working for the Royal Parks through their facilities contractor Carillion
Services we carried out a pumped desilting operation in Waterhouse
pond.
Three unifloates were mobilised to site and lifted into position
using a 25t all terrain crane. Space constraints and poor access to the site
necessitated the use of a small crane which had to be positioned very close to
the water. The unifloates were joined to form a pontoon and spud legs were
added. A 6t, long reach excavator was then positioned and chained onto the
floating pontoon.
Silt was dredged from the base of the pond and loaded into the pump
skip on the pontoon, the silt was then pumped approx 1km through a pipeline to a
disposal area within the park. Approximately 3500m3 of silt was removed in 1
week with minor disturbance to the area around the lake.
On a return visit to Waterhouse Pond we installed 2,500, 100mm
diameter, machine rounded timber posts up to 2.5m long. The posts formed a
revetment to stabilise the bank of the pond and create a safe edge for
pedestrians. The top of the revetment was restrained using ground anchors driven
up to 4m into the weak banks. The area between the posts and bank was then
filled with spoil, cultivated and seeded. A precast concrete headwall and 300mm
diameter penstock were also installed to provide another outlet from the pond
and greater control of water levels.
Waterhouse pond is situated at the
end of The Longford River which flows south from Heathrow, and distributes flow
to numerous watercourses in the park before flowing into the
Thames.
