The Epping Forest Conservation Centre has compiled dragonfly records from the
Forest ponds since the early 1970s. Several observers, including J. Adams. D. Woodfall
A. McGeeney and J. Bratton have contributed records during the present survey period,
but E. P. Ryan, in particular, has done immensely valuable work in recording the
Odonata of the Forest over a number of years. Table 3:4 gives a summary of records from
the more thoroughly worked Forest ponds, but there is. of course, no guarantee of
completeness. Though it is somewhat misleading to single out particular ponds. Wake
Valley Pond, with nineteen species recorded and Lower Forest Pond, with fifteen species
recorded, are outstandingly rich sites by any standards. Apart from sheer numbers of
species, the Forest is notable as the only location for Cordulia aenea in Essex (it occurs
on at least four Forest ponds). Another very local species. Erythromma najas occurs on
several of the Forest ponds, and Libellula quadrimaculata another very scarce Essex
species, has also been recorded in the Forest. Possibly because it has been more
intensively studied than other parts of the county. Epping Forest is also the main
locality for sightings of rare migratory species, such as Sympetrum flaveolum, and non-
breeding wanderers into our county, such as Aeshna juncea and Cordulegaster boltonii. It
remains to be seen whether the elusive Sympetrum danae will be confirmed as a breeding
species in the Forest.
(b) The Lee Valley
The quality of the River Lee itself as Odonata habitat has already been mentioned.
but when this feature is combined with the numerous flooded gravel pits which have
been formed in the flood-plain of the river, together with the large artificial reservoirs
which run alongside the river in the Walthamstow area, the whole complex provides an
unrivalled diversity of habitat. Numerous observers, most notably E. P. Ryan. G. J.
White and B. C. Eversham have studied the dragonflies of the Lee Valley during the
present survey period. The total of seventeen dragonfly species seen in one day on the
Cornmill Stream and Old River Lee near Waltham Abbey hy B. C. Eversham in 1983
must be a county record! Eighteen species in all have been recorded from the Lee Valley,
some, such as the scarce Platycnemis pennipes, breeding in the moving-water habitat,
whilst others, such as Orthetrum cancellatum and Libellula depressa favour the still-water
habitat provided by the gravel-pits.
The total number of breeding species (as distinct from the number of species recorded
as merely present) exceeds the Epping Forest list, making the Lee Valley probably the
most important dragonfly locality in the county. The best-studied site within the valley,
the Cornmill Stream/Old River Lee complex at Waltham Abbey, is of outstanding value
both botanically and for other invertebrate groups. It is one of the very few Essex
moving-water sites for Erythromma najas: has one of the strongest colonies of the
nationally threatened Platycnemis pennipes in Essex: and is the site for the sole post-1980
sighting of Coenagrion pulchellum in Essex. A short distance upstream, at Fisher's
Green, is another very strong colony of Platycnemis pennipes on the Cornmill Stream,
together with a good representation of still-water species on nearby flooded pits.
Unfortunately, the quality of the Cornmill Stream is now threatened by dredging
proposals, the aim of which is to increase the flow of water and render the site more
suitable for angling. Dredging, clearing of marginal vegetation and any resulting
increase in fish populations could all have disastrous effects on this prime dragonfly
site.
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