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Habitat Creation in the Lea Valley Park
The Waltham Abbey Site
One of the most exciting examples of the Authority's regenerative role is currently taking place
within sight of Epping Forest, between Waltham Abbey and Sewardstone. The Authority has recently
acquired over 220 acres of formerly industrial land and is in the process of integrating it into the
Regional Park by restoring it to landscaped parkland. The land was previously owned by Royal
Ordnance and used for the manufacture of products for mil itary purposes. The processes involved i n
their manufacture led to contamination of the land with a variety of toxic materials. Since closure,
the site has been the subject of complete decontamination by Royal Ordnance. This involved removing
all buildings, most vegetation and large amounts of soil. Following decontamination the site was
'capped' with a layer of London clay. The work was highly visible from both the M25 and Sewardstone
Road as an orchestra of heavy plant moved thousands of tonnes of soil, creating in the process a true
'brownfield' site!
Following consultation, the Authority has produced a Master Plan for the restoration of the area into
a parkland of regional significance which integrates with Sewardstone Marsh to the south and the
wider Lee Valley Park. The scheme will enhance characteristic ecological, hydrological and landscape
features, provide improvements to access and provide facilities for visitors. It is anticipated that the
scheme will take over two years to complete but the Park assures would-be visitors that it will be
worth the wait.
The rationale for the restoration and creation of the habitats and landscape on site are the Biodiversity
Action Plan (LVRPA & MHWT 2000) and Landscape Strategic Vision for the Regional Park.
Habitat Restoration and Creation
Existing ecological interest is centred on Osier Marsh - an area of wet woodland that regenerated
naturally on pulverised fuel ash (PFA) dumped into holes created by the extraction of sand and
gravel. The fuel ash once supported marsh orchids but these were lost as the woodland canopy
closed. The woodland contains a variety of willow species that have remained unmanaged. As the
trees have fallen and re-grown over the years an almost impenetrable tangle of dense woodland has
formed. The wood lies wet in the winter and supports Woodcock, wintering thrushes and large
mixed tit flocks. Long-eared Owls have roosted in the past. Muntjac deer arc common and a single
red deer has been reported on occasions. A vast amount of dead wood lies slowly decomposing and
it is expected the invertebrate interest will be of great interest. The nationally scarce and spectacular
Musk Beetle Aromia moschata is of particular note. Two large areas within the wood were formerly
used as burning grounds for unwanted material resulting from ordnance manufacture. Following
decontamination, the holes in the ground have been profiled to create shallow ponds with features
aimed at providing habitats for aquatic invertebrates and amphibians. As the ponds were being
profiled with heavy machinery, Black-tailed Skimmer dragonflies were already prospecting for egg-
laying sites! Wherever possible, pulverised fuel ash has been left exposed with the aim of providing
potential habitat for marsh orchids once more.
As land rises to the north and becomes drier willow is replaced by birch, again present entirely
through natural regeneration. The more open nature of the trees allows a more diverse ground flora
with beds of Yellow Iris, particularly attractive when in flower.
Forming the western boundary of the site is the Cattlegate flood relief channel. Over much of its
length, the channel has natural banks swathed in luxuriant emergent vegetation such as Purple-
Essex Naturalist (New Series) 17 (2000)