A reedy big project…

Before the reservoir was created the northern area of the reserve, specifically the tip of the north arm of the water, was part of a number of fish ponds belonging to the Burley Estate. Among the fishponds were some naturally occurring areas of reed bed. During the early development of the nature reserve in the 1970’s, reeds were transplanted from the fishponds to lagoon 3 where they were nurtured until they became established. Over time the reed spread and today form a dense red bed of Phragmites and Typha (“bulrush”) along the northern edge of the lagoon and supports a wide array of wildlife including overwintering bittern, otters, water voles, water rail,  reed warblers and sedge warblers to name a few.

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Lagoon 3 reed bed

Not only is the reed bed an important habitat for wildlife, it is also an important part of the water purifying process as water enters the nature reserve. As water passes through the reeds it is cleaned by the micro-organism’s living in the root systems (a mix of bacteria, fungi and algae) which digest sewage and cleanse the water – helping to provide optimum water quality for the biodiversity of the lagoon.

Over time, reed beds will naturally dry out as plant litter and silt build up,  and are encroached by scrub if regular management is not undertaken. Each year our staff and volunteers cut and clear a large section of reed on rotation (to ensure there is still plenty of mature reed available to for wildlife) to ensure leaf litter and dead plant material does not build up.
However, during the past 30 years silt has built up in the lagoon and has begun to affect the flow of water in through the vegetation and the water quality in the lagoon.  We knew we needed to undertake more drastic action to sort this out and that we would need the help of specialised machinery.

Thanks to very generous funding from Anglian Water, we’ve been able to hire a floating amphibious excavator which is adapted to the difficult terrain of the lagoon. The excavator has large floatation tracks which allow it to work comfortably on the water and access the reed bed with ease. The excavator is clearing large section of the reed bed where water enters the system, slugging out the silt and constructing a series of bunds which will hold water back in the remaining vegetation and ensure the area remains hydrated. The rhizomes will remain in the soil and in a couple of years’ time the Phragmites will return bringing the reed bed back in to optimum condition.

Photo: Joe Davis

Floating amphibious excavator (Photo: Joe Davis)