Information |
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| Date_registered |
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| 2026-02-12 |
| Brief_description |
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| The Onrus River Estuary, near Hermanus on the southern coast of the Western Cape, is a small estuarine system where the Onrus River meets the sea, historically forming a shallow lagoon with open water, reed beds, and wetland fringes that support diverse birdlife and aquatic habitats. The Onrus River Estuary forms part of the Cape Whale Coast IBA. The system has been severely disturbed by upstream water abstraction, reduced freshwater inflows, nutrient enrichment, bacterial contamination from aged and damaged sewage infrastructure, and extensive growth of common reed (Phragmites australis), which has reduced open-water areas and biodiversity. Urban development around the estuary and related recreational pressures further alter habitat and contribute to water-quality issues, underscoring the importance of integrated management and restoration for the estuary’s ecological health and recreational value. |
| Hydrological_features |
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| • Estuarine waters – permanent water of estuarine systems (90%)
• Intertidal mud, sand, or salt flats (10%)
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| Ecological_features |
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| WETLAND COMPOSITION:
• Emergent vegetation (60%) – Common reed
• Open water (35%)
• Sand/ mudbanks (5%)
• Surrounding vegetation: Fynbos, Strandveld, IAP cover, Trees, Shrubs, Grasses
• Dominant substrate type: mud
• Acidity: unknown
• Salinity: Brak – Saline (dependent on mouth conditions)
• Approximate size: 11 ha
• Approximate maximum depth: 1-2m (dependent on timing of dredging)
• Site/ wetland context: Single, discrete wetland |
