The site and its birds
Rye Meads is an area of flood plain beside the River Lea near the town of Hoddesdon in Hertfordshire. The Lea Valley has been extensively worked for gravel extraction, leaving a legacy of flooded pits along a north-south axis which forms an attractive natural migration route for many waterfowl and waders, and indeed for many other species of marsh and scrub habitats.
About the site
The study area covers the former extent of the Rye Meads Sewage Treatment Works, covering several hectares of sludge beds, lagoons and meadows, and these in turn are adjacent to active and abandoned gravel pits and marshes. The area is shown on this Google Map.
In the 1990s, most of the land to the north of the Rye Road was passed from Thames Water to the RSPB for their management, and is now the bulk of the RSPB Rye Meads Nature Reserve. The Ringing Group continues to study the birds in this part of the site in active co-operation with the RSPB reserve management.
We also continue to study the southern area of the site, comprising the treatment works and settlement lagoons, by arrangement with the site owner, RWE Thames Water.
Much of the site and the surrounds have been designated a Site of Special Scientific Interest (SSSI). In addition, on the 22nd September 2000, a number of sites in the Lea Valley were designated as Special Protection Areas (SPAs) and also listed as Wetlands of International Importance under the "Ramsar convention". Rye Meads was one of these, the others being Amwell Quarry, Turnford and Cheshunt pits, and Walthamstow Reservoirs. The Rye Meads designated site covers the current SSSI, which includes the south lagoons, the RSPB reserve, the North Lagoons, and the Meadows.
The birds of Rye Meads
Rye Meads has been given this special protection because of the internationally important wintering populations of Bittern, Shoveler, and Gadwall, and nationally important numbers of Cormorant, Great Crested Grebe, Tufted Duck, Pochard, and Grey Heron. The lagoons are an important refuge for many other species of wildfowl, and also attract some inland passage waders; and some of these are also trapped for ringing.
Conservation work has developed a number of the smaller north lagoons that were no longer required by the Works and were incorporated into the RSPB reserve into a large area of shallow water with reedbeds, nicknamed "The Scrape". This attracts various waders and water rails, and with the maturing of the reedbeds a breeding colony of reed warblers has become established, and we have seen the first winter flock of bearded tits.
The main trapping areas are in scrub around the lagoons, mainly willow with some sallow, hawthorn and oak. This scrub is managed to prevent its degeneration into mature trees. These areas contain significant breeding populations of many wet scrubland birds, particularly warblers.
Rye Meads also has a small but significant winter population of Chiffchaffs, thanks to the sewage treatment works' outflow of relatively warm, insect-rich water through the winter months.
Finally it is worth mentioning that the location of Rye Meads, in the north-south running Lea Valley, is in an inland migration corridor, which leads to modest influxes of migrant birds in the spring and autumn.