Project Summary and
The fen restoration has been a mammoth task, involving
a wide range of innovative measures. The total cost of the restoration
was approximately £3.4 million.
The restoration has received critical acclaim,
with the Project being chosen to demonstrate wetland recovery by
the EU LIFE fund, which also awarded 50% of the Project costs. In
1997, the project was the overall UK winner for the Henry Ford European
Conservation Award. The East of England Tourist Board highly commended
the project and new Visitor Centre in their 'Tourism and the Environment'
category for the 'England for Excellence' awards 1998. In March
2000, the project was highly commended for the Chris Binnie Award
for Sustainable Water Management (granted by the Chartered Institution
of Water and Environmental Management). In October 2001, the most
recent accolade has been to win the Eurosite 2001 award for habitat
restoration on a Natura 2000 site. Such accreditation helps reinforce
that the future of this spectacular reserve now looks very bright
Back in late 1950's, there was an increasing local
demand for good quality water in the locality, primarily for housing
and local business. The natural supply of pure groundwater in the
aquifer below Redgrave and Lopham Fen was seen as an excellent source
of water to meet this demand. In 1957, a borehole and pumping station
was sited within 30m of the fen, being commissioned in 1959 to remove
removed approximately 3600 cubic metres of water on a daily basis
from the chalk aquifer below the fen.
Project aim: To re-establish
the original fen water regime by moving the borehole
At the start of the restoration project, the search
began for a new borehole. It had to provide enough water of the
right quality to supply the Company's customers. It had to be near
enough to the old site to be economic to build, yet far enough from
the Fen and other wetlands to be safe. The search involved enormous
scientific investigations. Many candidate sites were drilled and
tested; most were rejected. One favourite emerged. It was tested
in great detail, including extensive environmental monitoring. It
failed because it did not produce sufficient water. A second site
was tested, and succeeded.
Project aim: To ensure that
the new borehole provides a secure public water supply without damaging
By far the most important recent restoration success
has been the relocation of this borehole 3km southeast of the reserve.
The planning, development and construction of the new borehole cost
the Project approximately £1.2 million, and has been a significant
achievement not only in financial terms, but in the fact that this
has been the first time a public water borehole has been relocated
on environmental grounds alone.
Borehole relocation and changes seen on
The borehole was shut down in early July 1999. The
event was marked with a large ceremony attended by Prof. David Bellamy
and set in motion the long-depleted artesian groundwater supply
upward to the fen soils. Within a month, significant physical changes
were occurring on the fen surface and large increases in water levels
were recorded in the 50 dipwells on the reserve. Massive flushing-out
of ochreous sediments from the fen soils resulted in the River Waveney
appearing 'brick' red for almost 2 months, and then continuously
brown ochre-coloured for another 30 months.
The groundwater cleaning-up process
has been fascinating. Relating field observation to theory, it is
likely that the extreme drop in water levels in the fen soils that
had occurred every summer for 4 decades, had resulted in regular
deposits of ochre (oxides of iron) precipitating in the fen soils.
In early summer 2002, the appearance of ochre in the river ceased.
It is believed that the maximum level of groundwater recharge has
now been attained, and that the level has settled slightly. It is
now expected that only extreme rainfall or drought events will be
the determinant factors in producing significant quantities of ochre.
To date, the hydrological recovery in the river catchment has responded
closely to groundwater modelling undertaken by ENTEC UK as part
of the restoration project.
In many respects, the return of the natural artesian
groundwater supply has solved the major hydrological problems of
the fen. Peat soils now remain significantly wetter during the growing
season than before, with tolerable drawdowns in the surface and
chalk water levels. The formerly desiccated sedge beds typically
have water at, or near fen surface, as opposed to a minimum of 0.5m
below fen surface prior to borehole relocation. Old peat cuttings,
which exist in their thousands all over the reserve, now resemble
small ponds in various stages of ecological succession, many of
which will be left to close over with a floating mat of fen vegetation.
The River Waveney
Project aim: To raise
water levels in the River Waveney and restore the river habitats
Redgrave and Lopham Fen is divided by the River Waveney, the river
corridor habitat is extremely important within the framework of
Between the late 1960's and
70's, long before the restoration project began, 2 simple sluices
were installed in the River Waveney to help reduce the effects of
water loss from the reserve. Although these structures helped maintain
higher water levels in the river for some years, they were not ideal
in the long term, having little in the way of fine adjustment.
The most significant
achievement on the river corridor has been the removal of the old
sluices and the installation of 2 fully adjustable sluices on the
river. One of the new sluices has been sited in a new location on
the river, affording increased protection to the eastern-most region
of the reserve. Prior to the restoration Project partnership, this
area had no sluice to protect it from rapid drainage of the fen
soils. The installation of this new structure would also have been
dismissed as unachievable, there being several private landowners
potentially being affected by restoration of this section of the
river channel. Much work has gone on behind the scenes during the
Project negotiating with landowners. The Ramsar and Special Area
of Conservation (SAC) designations have significantly helped in
raising the international profile of the fen, and its essential
requirement for a suitably intact hydrological regime.
Reprofiling the banks
of the River Waveney
As part of the restoration project
works, sections of the almost vertically-sided river bank have been
graded back to an angle of approximately 25 degrees, affording a
wider channel with greater marginal interest for wildlife. Material
removed from the bank has been incorporated into a discrete flood
defence bund, that channels eutrophic winter floodwater downstream,
away from the sensitive fen habitats. Other work has been undertaken
in autumn 2002, with shallow shelves also being incorporated along
sections of the channel between the two river sluices. These recent
works have been deliberately undertaken prior to operation of the
new river sluice, and will provide immediate additional bankside
burrowing habitat for water voles when the river level is restored.
We are monitoring the quality
of water that comes off the surrounding agricultural fields so that
controls can be adopted in the future. Between them, these measures
should cure the problems caused by agricultural intensification
in the surrounding catchments.
The fen habitats
Project aim: to re-create the habitat conditions
which will allow the most important fen communities to reestablish.
Scrub and Tree Clearance
The restoration project identified approximately 80
hectares of invasive scrub and trees that required complete removal.
Over 36 hectares had already developed into mature scrub and young
secondary woodland with the remainder being scattered throughout
the remaining pockets of open fen vegetation. The scrub removal
programme has been completed successfully, with all the targeted
dense and scattered scrub felled and removed from the reserve. This
was a massive undertaking, particularly considering the extremely
awkward wet soils and hazardous topography that had to be to negotiated.
Many hectares of scrub and woodland edge will remain
on the fen as a valuable contrasting habitat to the open fen vegetation.
Annual scrub clearance now focuses on maintaining the open fen,
and preventing rapid reinvasion of young scrub species again, rather
than trying to remove all the scrub from the reserve.
Peat Stripping Operations
At the start of the project,
Sheffield University measured the fertility of the peat. This was
compared to the fertility of peat associated with fen vegetation
types we wanted to reestablish As expected, four decades of significant
groundwater abstraction from the reserve had resulted in a significant
percentage of the surface fen peat becoming highly desiccated, oxidised
and very eutrophic. The only restoration option was to strip off
the degraded surface layers down to undamaged, saturated peat.
By late 2002, a total of some 26 hectares has been stripped, removing
approximately 250,000 tonnes of peat. These areas currently comprise
predominantly open water. In all these areas the annual cycle of
vegetation growth and dieback will gradually restart the process
of fresh peat formation.
Peat Path and Bund Creation
A by-product of many of the peat stripped areas on
the reserve has been a number of relatively linear, landscaped peat
baulks, comprising the degraded peat. The majority of these have
been utilised to form a combination of protective flood banks, or
public, livestock or machinery access paths. Due to the volumes
of peat arisings, some baulks have remained on site more as visual
intrusions than practical solutions. Additional work has been undertaken
in 2001 and 2002 to restore several kilometres of degraded access
and management paths, utilising material from these features. This
has had the combined beneficial effects of removing unattractive
strips of peat whilst vastly improving access and management possibilities.
The majority of restored paths have had a 4m wide polymer geogrid
laid under the surface, affording greater stability, and restricting
'poaching' of path surfaces by livestock, machinery wheels and visitors'
feet. The raised paths have also had several pipes laid in at the
path base, to prevent ponding of surface water within the open fen
beside them, and to prevent wet and structurally-weak areas forming.
Regular flooding and the soft, uneven terrain means
very specialised equipment was required to undertake all the project
work. A great deal of time was spent developing innovative yet cost
effective machinery, from the digger, through to transporters, tractors
and cutting gear. These developments have been made widely available
to wetland managers, through site visits, articles in relevant journals
and in the press.
on the diggers and large machinery
grazing regime has been introduced to maintain the vast expanse
of the Fen at low cost - mowing is too slow and expensive. To maximise
fen diversity, we graze with Hebridean sheep, Sussex cattle and
on the Tarpans
Fen Raft Spider
maintain the population of fen raft spider, Essex and Suffolk Water
installed an irrigation network to their core breeding pools. This
combined with management work on the pools stabilised the population
during the restoration work, particularly during the very dry summers
in the mid to late 1990's. It is extremely
rewarding to report that this irrigation pipe network has not been
required since the borehole was relocated in July 1999, as the natural
groundwater levels have been recovered.
on the fen raft spider