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Good practice Imported

Wallasea Island Wild Coast — Crossrail Spoil Used to Rebuild Saltmarsh and Mudflat in Essex

United Kingdom · Wallasea Island · See the United Kingdom profile

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Three million tonnes of London Crossrail tunnel spoil raised farmland before the sea wall was breached in 2015. RSPB reports 650+ ha of lagoon, mudflat, saltmarsh and grassland and a record 38,000 waterbirds in Dec 2023.

Wallasea Island Wild Coast — Crossrail Spoil Used to Rebuild Saltmarsh and Mudflat in Essex

Details

Promoter
RSPB with Crossrail, Environment Agency and funders
Period
2008–2018 (ongoing monitoring)
Keywords
managed realignment, saltmarsh, mudflat, beneficial reuse of spoil, waterbirds

Description

The RSPB's Wallasea Island Wild Coast Project in Essex reused about three million tonnes of excavated material from the Crossrail (Elizabeth line) tunnels to re-profile low-lying farmland, then breached the sea wall in July 2015 to restore tidal habitat.
The RSPB reports over 650 ha of lagoons, mudflats, saltmarsh and coastal grassland created across the works (2015–2018). Monthly Wetland Bird Surveys recorded a record 38,000 waterbirds in December 2023, above the previous 32,770 (January 2020).
Secondary sources describe avoided sea-wall maintenance and carbon-storage benefits, but they differ on areas and costs (for example 115 ha of tidal habitat in the NbS Knowledge Hub versus 650+ ha reported by the RSPB), so those numbers should be treated cautiously.
Caveat: bird counts demonstrate biodiversity gain but there is no independently verified carbon or flood-damage figure in the sources used.

Read the full analysis: https://www.rspb.org.uk/whats-happening/news/record-number-of-birds-at-wallasea-island

Implementation

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