Walthamstow Reservoirs is the name given to a group of various-sized bodies of water lies north of Stamford Hill, East of Tottenham, south-west of Walthamstow and is bisected by Ferry Lane. The site is also sandwiched between Walthamstow Marshes [to the south-east], and Tottenham Marshes [to the north-west].
There are three reservoirs north of Ferry Lane (in order from north to south):
- Lockwood Reservoir (TQ352901)
- High Maynard Reservoir (TQ354896)
- Low Maynard Reservoir (TQ351895)
and seven on the south side (in order from north to south):
- Walthamstow Reservoir Number Four (TQ353890)!!
- Walthamstow Reservoir Number Two (TQ351889)!!
- Walthamstow Reservoir Number One (TQ349888)!!
- Walthamstow Reservoir Number Three (TQ351886)!!
- Walthamstow Reservoir Number Five (TQ353886)!!
- Warwick Reservoir East (TQ348884)!!
- Warwick Reservoir West (TQ346881)!!;)
Of these, only Nos. 1 to 3 and Warwick Reservoir East on the south side, and Low Maynard on the north side, are still fully accessible without a permit.
The main entrance is on Ferry Lane N17 where there is a car park, and space for locking bicycles. Permits for birding purposes in non-public areas and for any access outside normal visiting hours (9.30 am to 4/5pm) can no longer be obtained at the gatehouse, and must be specially applied for via the visitor centre - Walthamstow Wetlands is 2 Forest Road, London N17 9NH. The nearest tube stations are Blackhorse Road and Tottenham Hale, both a 5 minute walk away. The complex is managed by Thames Water, and very popular with anglers.
The larger reservoirs are typical in having concrete banks and, at first glance, offer little to tempt any passing migratory wader. The other lakes have the appearance of those left after gravel extraction.
Although a visit at any time of year can be rewarding, the site can be quiet in the summer except for the large numbers of breeding Cormorant, Grey Heron, Tufted Duck, Lesser Black-backed Gull and Common Tern. The reservoirs hold nationally important numbers of Tufted Duck in the early autumn — during July to early September their numbers will peak at about 2000!
In winter, relatively large numbers of ducks and geese can be present, and it is always worth checking the adjascent filter beds on Coppermill Lane for gulls. March is the best time for Mediterranean Gull and November for Yellow-legged Gull, although both have been known to overwinter. There are a number of islands, each with its own character. The island on East Warwick usually holds breeding Lesser Black-backed Gull and Herring Gull, and Common Tern can be found on several purpose-built rafts around the site in summer; the island is also a favoured spot for Lapwing. Reservoir Nos.1 and 2 hold the famous heronry, nesting beginning in early February; No.1 island held London's first breeding Little Egret in summer 2006, with two pairs in summer 2007. The island on the No.5 holds the even more famous Cormorant colony - the population numbers around 300 pairs, with most activity from late February to late July.
If you wish to see passage waders, it is worth visiting the site at first light, as they have a habit of disappearing after flushing. If a reservoir is drained, anything could occur. Note that during persistent rain, waders appear throughout the day. If you fancy your chances of finding a scarce Diver or Grebe, keep your eyes open: the last Black-throated Diver crashed into pylons and landed in the Coppermill Stream, beside the Low Maynard.
With this group of reservoirs lying next to the river Lea [being part of the Lea Valley Regional Park], it is likely that birds use the river for navigation, and therefore anything can turn up. A sizable flock of Tree Sparrow used to frequent the centre of the site (near the island with breeding herons), but they died out during the mid-1990s. Other small birds to keep an eye out for are Wheatear, Whinchat and Stonechat, but it is also worth grilling any pipits and larks for waifs and strays.
Recent sightings are recorded on a blog: Walthamstow Birders