Protection or relocation of habitats?

The Wash and surrounding area is fundamentally a man-made environment, resulting from the building of extensive coastal defences and mechanical draining of marsh and fen. However, it is important for a wide range of birds, animals and plants.

Climate change, sea level and the current ‘managed retreat’ policy for sea defences put most of these habitats at risk. The Barrier gives the opportunity to protect, relocate and improve these important biodiversity habitats and indeed create new ecosystems to host species displaced by climate change.

Flood protection

The Barrier will provide flood protection for more than 500,000 people, 300,000 hectares of grade 1 agricultural land and billions of pounds’ worth of assets. While building higher significantly adds to the cost, the probability of the Barrier being overwhelmed is greatly reduced.

"What height should the Barrier be?"

Electricity generation

Using the tide to generate power is one of the greenest and most dependable sources of sustainable energy. The Barrier has the capacity to generate over 1GW of electricity, equivalent to the output of two nuclear power stations!

A single lagoon system for generating electricity has the advantage of using a single barrier, and is thus the most economic option. However, the electricity generated will peak and dip four times a day with the tide. Tide movement behind the Barrier will be similar to that which we see today, though typically will be out of phase with natural tides and have a lower tidal range.

With a multiple lagoon system, electricity can be generated under full control, allowing the system to provide it at any time, with the option to turn off and on in a moment (spinning capacity). This could compensate for the variability of demand and supply from sources such as wind power. However, a multiple lagoon system would require more than twice the length of barriers needed in a single lagoon system and would radically change water movement.


The Wash currently provides a very limited sea fishery. The lagoon system could be managed to provide farmed sea fish, shellfish etc.

"To what extent should the lagoon system be tailored to food production?"


The Wash is very difficult to access for leisure. The large tidal range, treacherous currents and high levels of silting mean that access is limited.