How UK River Restoration Can Keep Wetlands Green During Drought
When a river is straightened, deepened and separated from its floodplain, water moves quickly through the catchment. That can worsen flood peaks after heavy rain and leave less water stored in the surrounding soil and wetlands when dry weather arrives.
The Holnicote Estate in Somerset offers a different model. Since 2018, the National Trust has restored parts of the Aller and Horner Water catchments by reconnecting rivers with their floodplains, expanding wetlands and reintroducing beavers in enclosed areas.
The river is given room to spread
The centrepiece is a 1.2-kilometre section of the River Aller restored using a method known as “Stage 0”. Instead of forcing the river to remain in one engineered channel, the project filled the old channel and allowed water to form a network of shallow channels, pools, marshes and wet grassland.
This creates what the National Trust describes as a natural sponge. During wet periods, water can spread across the floodplain, slowing its journey downstream. During dry periods, saturated soils, ponds and wetlands can release water gradually rather than losing it all through rapid drainage.
The Environment Agency’s evidence review supports the basic mechanism but warns that results vary by site. Floodplain restoration can delay or reduce some flood peaks, while improved connectivity may also increase local inundation. The effect depends on the restored river’s length, the catchment’s geology and the size and position of the floodplain.
Why the restored ground can stay greener
Wetlands hold water close to the surface, creating cooler and moister conditions for plants during heat and drought. Beaver dams can add to this storage by slowing streams, raising local water tables and spreading flow into side channels and ponds.
A 2025 Environment Agency case study reports a 38% reduction in flood peak and a large increase in groundwater measurements at the restored Aller site. Those figures describe a particular project and monitoring method; they should not be treated as a guaranteed result for every rewilding scheme.
The wider evidence is also stronger for flood-risk reduction than for water-supply benefits. In a 2026 position statement, the Environment Agency said nature-based approaches can improve drought resilience through better soil retention, more sustained river flows and groundwater recharge, but noted that fewer studies have examined water resources than flooding.
A buffer, not a cure-all
Restored catchments cannot end a drought caused by prolonged rainfall deficits, high water demand or depleted reservoirs. Nor can wetlands protect every downstream community from extreme floods. They work as one part of a wider system that may include water conservation, conventional flood defences, better soil management and careful land-use planning.
Holnicote’s significance lies in showing how river restoration can serve several purposes at once: creating habitat, improving water quality, supporting farming and making parts of a catchment less vulnerable to both very wet and very dry weather. The results are encouraging, but long-term monitoring will determine how reliably those benefits persist as the restored landscape matures.