The Severn Estuary: Where England Meets Wales

The **Severn Estuary** is a massive, dynamic tidal inlet forming the **border between South West England and South Wales**. It is the mouth of the **River Severn**—Britain's longest river—and a designated **Special Area of Conservation (SAC)** and **SPA** for its unique ecology.

Geographic Definition

• Extends: From **Second Severn Crossing (M4 bridge)** / **Severn Bridge (M48)** upstream to **Gloucester** (tidal limit), and seaward to a line between **Lavernock Point (Wales)** and **Sand Point (England, near Weston-super-Mare)** where it meets the **Bristol Channel**.
• Coordinates (approx.): 51°25'N – 51°45'N / 2°35'W – 2°50'W.
• Length: ~**35 miles (56 km)** inland from the Bristol Channel.
• Width: Up to **~9 miles (14 km)** at its mouth.

Key Features

• Massive Tidal Range: **2nd highest in the world (up to 15m / 50ft)**. Creates the famous **Severn Bore**—a surfable tidal wave rushing upstream.
• Major Ports: **Avonmouth, Bristol, Sharpness, Newport, Cardiff** (though Cardiff Bay is now impounded).
• Crossings: **M4 (Prince of Wales Bridge), M48 (Severn Bridge), Aust Ferry (historic), Severn Tunnel (rail).**
• Ecology: Vast intertidal mudflats, saltmarshes, rocky shores. Critical for **wintering wildfowl/waders (dunlin, shelduck, Bewick's swan)** and fish migration (salmon, eel, shad).
• Energy: Proposed **Severn Barrage** (tidal power) debated for decades; not built.

The Estuary is a working landscape: heavy industry, nuclear power (Hinkley Point, Oldbury), major ports, and internationally vital wildlife habitat, all shaped by one of the planet's most powerful tidal engines.