Definition
Clanwilliam Dam is a large water‑storage structure on the Olifants River near the town of Clanwilliam in the Western Cape province of South Africa. The dam primarily serves municipal water supply, agricultural irrigation, and recreational purposes.
Overview
- Location: Approximately 15 km east of Clanwilliam, Western Cape, South Africa, within the Olifants River catchment.
- Construction period: Built during the 1970s; the dam was commissioned in 1978.
- Operator: Department of Water and Sanitation (formerly Department of Water Affairs and Forestry).
- Purpose: Provides potable water to the surrounding region, supports irrigation schemes in the Cederberg and Hex River valleys, and creates a reservoir used for fishing, boating, and tourism.
- Significance: The dam is a key component of the Western Cape’s water‑resource management strategy, particularly during periods of drought.
Etymology / Origin
The dam is named after the nearby town of Clanwilliam. The town itself was named in 1814 after the Earl of Clanwilliam, a title in the Peerage of Ireland, reflecting the British colonial practice of commemorating aristocratic titles in place names.
Characteristics
| Feature | Description |
|---|---|
| Dam type | Concrete gravity dam (with auxiliary earth‑fill embankments). |
| Height | Approximately 33 m (108 ft) above the riverbed. |
| Length | Roughly 300 m (984 ft) crest length. |
| Reservoir name | Clanwilliam Dam Reservoir (also known locally as the Clanwilliam Dam Lake). |
| Storage capacity | About 1 600 million m³ (1.6 km³) of water at full supply level. |
| Surface area | Approximately 13 km² (5 sq mi) when at full capacity. |
| Spillway | Ungated overflow spillway with a capacity of roughly 3 500 m³ s⁻¹. |
| Catchment area | Around 9 300 km² of the Olifants River basin. |
| Primary uses | Municipal water supply, irrigation, recreation, and flood control. |
| Environmental considerations | The reservoir supports a range of aquatic species, including the endemic Clanwilliam yellowfish (Labeobarbus seeberi); water‑level management incorporates ecological flow requirements downstream. |
Related Topics
- Olifants River (Western Cape): The river on which the dam is situated.
- Western Cape Water Supply System: The broader network of dams and pipelines that deliver water across the province.
- Cederberg Mountains: The mountainous region surrounding the dam, noted for its biodiversity and tourism.
- Clanwilliam Yellowfish (Labeobarbus seeberi): An endemic fish species of conservation interest within the reservoir and downstream waters.
- South African Dam Infrastructure: Overview of dam construction, management, and policy in the country.
All information presented reflects data available from South African governmental water‑resource publications and reputable geographic sources.