Channelsea Island is an unexpected haven of green, hidden away on a dead end tributary of the River Lea and Bow Creek. The island sits between Abbey Mills Pumping Station and a razed flatland of former chemical works.

The island cannot be reached on foot, although it can be viewed from nearby footpaths. We visited using kayaks, wearing appropriate safety gear and buoyancy aids.

The Bow Back Rivers

The Channelsea is a remnant of the Bow Back Rivers, a web of waterways which once fanned out from the River Lea. The many rivers drained the boggy Stratford marshlands, before entering the Thames at Bow Creek.

Over the years, the Bow Back Rivers have been embanked, re-routed and culverted. Most have now been incorporated into the Olympic Park. As a result, much of the Channelsea’s former riverbed is now buried below Stratford.

Most of the Bow Back Rivers have been cut off from the salty waters of the Thames, but the remaining stretch of the Channelsea is still tidal. As a result, Channelsea Island can only be reached by boat, at high tide. The island is completely overgrown, and access is not easy.

Ancient water mills

A series of tidal mills stood at the northern tip of the island, perhaps as far back as the 11th century. These mills were located where Abbey Road is now. However, the island no longer reaches this far north. Some say Channelsea Island was built to support the original mill, but this seems unlikely. The western channel around the island is called Abbey Creek, and this could have been cut to allow an additional water wheel to be added to the mill, thus creating an island below the mill.

The mill went through many rebuilds, before finally burning down during World War 2. Most of the ruins were removed in 1967 when Abbey Road was straightened, and a new bridge built.

Abbey Mills Pumping Station

Until recently, Abbey Mills Pumping Station was discharging 16 million tons of overflow effluent into the Channelsea River every year. These overflows occurred when the sewage system was overwhelmed by rainfall. The turbulent discharges may have eroded Channelsea island, or the island could possibly have been manually cut back to facilitate the overspill. Fourteen huge overflow pipes can still be seen here, if the tide isn’t too high, facing the river.

These days, the majority of overflow sewage spills into the Lee Tunnel instead of the Channelsea. The tunnel was opened in 2016 to funnel excess effluent to Beckton Sewage Works in the east.

Under normal circumstances, Abbey Mills Pumping Station pumps the majority of north London’s sewage towards Beckton via the Northern Outfall Sewer, built in the 1860s. The pipes of the Northern Outfall Sewer bridge the Channelsea, north of the island. The Greenway footpath now allows walkers to follow the route of these pipes, almost all the way to Barking Creek.

Abbey Mill Chemical Works

Aside from the mill, Channelsea Island seems to have remained unoccupied until the early 20^th century, when the neighbouring Abbey Mill Chemical Works expanded onto the island. Aerial photographs from 1923 show a series of four interlinked buildings, with ancillary structures. In these images, the edges of the island have been re-enforced with piling, which exists today.

Abbey Mill Chemical Works opened around 1870 and produced sulphuric acid. Records indicate that the buildings on Channelsea Island were used for chemical production and storage. The remnants of thick glass pipes on the island suggest the processing or storage of corrosive acids here.

Tales of secret military experiments on Channelsea Island during World War 2 are probably just rumour, but the chemical works may well have supported the war effort.

Abbey Mill Chemical Works was decommissioned in the late 1980s, and the majority of the site demolished in 1992. The buildings on Channelsea Island were emptied and abandoned to decay. Nature and wildlife have reclaimed the island.

Beware of the plants

The buildings are in a very poor state, with collapsed and collapsing roofs. In places the soil is unnaturally red and friable. The undergrowth is thick and in places, dangerous. Giant hogweed grows here. If you accidentally brush against the plant the sap can badly blister your skin. This blistering can recur over months and even years and occasionally features in lurid tabloid tales.

From chemical works to mega-mosque?

The former chemical works and Channelsea island now belong to a missionary movement known as Tablighi Jamaat, which hopes to build a large mosque on the site. However, Newham Council has repeatedly refused permission for construction. One reason for the refusal is the chemical contamination across the site, which will require extensive and expensive remediation.

A temporary mosque known as Abbey Mills Mosque currently operates from the former chemical works, but its days may well be numbered. Newham Council has long-term plans to develop the site for residential and commercial purposes.

Channelsea Island’s wild future?

Channelsea Island’s future as a rarely visited and wild island will hopefully be secure. The island is best left as a green oasis. Little egrets perch on branches over the river, their brilliant white feathers contrasting with the dirty greys of the larger herons.

Smaller birds nest amid the tangled branches, and the surrounding reedbeds provide shelter and sustenance for all sorts of wildlife.

My thanks to Karina Townsend for joining me on this trip and for additional research.

Thanks also to the friendly faces at Cody Dock, who allowed us to launch from their pontoon. Their café will hopefully reopen soon. Cody Dock is well worth a visit, offering wide views of Bow Creek and the London skyline.

Note: Strong tidal flows, mudflats, exposed conditions, pollution and river traffic can present significant problems for the paddler. As experienced kayakers we undertook this trip using kayaks in June 2020. Exploring derelict buildings comes with obvious risk.