Sediment management in the Waikato region, New Zealand

摘要

The Waikato region covers much of New Zealand's central North Island and has a land area of about 25,000 square km. The region encompasses about 44,000 kilometres of waterways, including three larger river catchments — the Waikato River (11,353 km2), Waipa River (3092 km2) and the Waihou River (1275 km2). The soil resource is vital to the Waikato region's wellbeing, and safeguarding it requires sound knowledge of the resource and effective erosion and sediment management. The sediment regime within the Waikato region reflects both natural processes and modification of natural processes (under present climatic and landscape conditions), including changes in land use, hydro-electric power development, sand and gravel extraction and channel management works. Waikato Regional Council (formerly Environment Waikato) has several sediment management roles, including regional monitoring and research, policy development and management implementation. Information about sediment sources and sediment movement through the region, as well as ways to prioritise decision-making, are an integral part of regional sediment management. Policy development and implementation through education and rules need be evidence-based and practical. To achieve this, continued monitoring and research, including collaborations with external research providers, is critical. Examples of how sediment-related monitoring and research has assisted sediment management in the Waikato region are summarised in this paper.