| Cardiff Bay Barrage | |
|---|---|
 Bascule Bridges | |
| Official name | Cardiff Bay Barrage |
| Country | United Kingdom |
| Location | Cardiff, Wales |
| Coordinates | 51°26′53″N 3°09′53″W / 51.44812°N 3.1647°W |
| Status | Operational |
| Construction began | 1994 |
| Opening date | 2001 |
| Construction cost | £120m |
| Owner(s) | Welsh Government |
| Operator(s) | Cardiff Harbour Authority |
| Dam and spillways | |
| Type of dam | Barrage |
| Impounds | Cardiff Bay |
| Height | 7.96 m (26.1 ft) |
| Length | 1.1 km (0.68 mi) |
| Spillways | 5 |
| Spillway type | Controlled |
| Spillway capacity | 2,250 m3/s (79,000 cu ft/s) |
| Reservoir | |
| Creates | Cardiff Bay |
| Surface area | 200 hectares (490 acres) |
| Normal elevation | 4.5 m (15 ft) OD |
Cardiff Bay Barrage (Welsh: Morglawdd Bae Caerdydd) lies across the mouth of Cardiff Bay, Wales between Queen Alexandra Dock and Penarth Head. It was one of the largest civil engineering projects in Europe during construction in the 1990s.