Land Drainage

138 2012-22 Hauraki Long-Term Plan – Volume 1 of 2 Land Drainage What is the Land Drainage activity and why is the Council involved? Land Drainage and Flood Protection and Control activities both work towards achieving the same goals in terms of retaining the productive capability of the land, therefore these activities have been incorporated into one Group of Activities called Land Drainage. The Council also believes that Land Drainage is the most easily understood name for this activity for those who are affected. The legislative requirement for the Flood Protection and Control Works activities is set out in section 2 of the 10 schedule of the Local Government Act, 2002. Land Drainage is a particularly significant activity for Hauraki District Council, more so than for most other local authorities in New Zealand. The Council has Land Drainage standing committees that have representatives from both the Council and users that advise the Council on land drainage and flood protection and control measures. Land drainage and flood protection and control are key functions of the Council’s operation, as a considerable portion of the northern Hauraki Plains lies at or below the normal high tide level in the Firth of Thames. The remainder of the land on the Hauraki Plains is only slightly above this level, so protection against high water tables, extreme weather events, high tides and river floods is essential to the continuing occupation and use of the land for residential, agricultural and horticultural purposes. Flood Protection The majority of the Flood Protection activity in the Hauraki District is provided by the river schemes of the Waikato Regional Council, except in the northwest part of the District (Waitakaruru to Miranda) where it is provided by Hauraki District Council. The assets that provide direct protection from river and tidal flooding include stopbanks, floodgates and pump stations, and are referred to as primary flood protection assets. Land Drainage Land drainage assets collect runoff from the catchment areas of the District and convey it to the primary flood protection assets which discharge it direct to river or sea outlets. In addition to the drainage network, land drainage assets can include stopbanks, floodgates and pumps. The latter drainage assets perform a land drainage function, e.g. pumping from a minor drain into a major drain; they do not provide direct protection from river and tidal flooding, and are referred to as secondary protection assets. These services are provided by the Council in three Drainage Districts: The Western Plains Drainage District which lies between the Piako River and State Highway 27, from the Firth of Thames to the District boundary with Matamata-Piako District Council. The Eastern Plains Drainage District which lies between the Piako River and the Waihou River, from the Firth of Thames to the District boundary with Matamata-Piako District Council. The Paeroa Rural Drainage District which comprises three smaller former drainage districts east of the Waihou River. The former districts were the Komata North, Opukeko and Tirohia Rotokohu drainage districts. The Land Drainage activity provides protection in a sustainable manner, through achieving a high degree of public safety and effective protection of property, farmland and roads by draining excess surface water and managing ground water levels. The Land Drainage activity delivers services which the community needs to function productively and comfortably on a day to day basis, which meet high community health and safety standards, and which promote continuing productive use of the land. Land Drainage 139 There is a community demand for Land Drainage services, and also an expectation that sustainable management of the environment will be a key driver in the design and management of the systems. How does the Council provide this activity? The Council carries out the Land Drainage activity by maintaining drains, canals, control structures, floodgates, flood pumps, culverts and stopbanks. Maintenance of the drains ensures that effective performance of the drainage system in removing surface runoff can be relied upon in order to meet the agreed level of service. Council drains are maintained by a combination of spraying and machine cleaning programmes, conducted by the Council’s Construction and Maintenance business unit. Each drainage district has its own advisory committee of members elected to represent ratepayers specifically on drainage matters in their area. The Western Plains Drainage Committee also has responsibility for the management of the flood protection aspect of the activity. The drainage advisory committees report directly to the Council. The drainage committees establish levels of service with the Council and the community and recommend the annual or on-going works programme. The Council then sets the rates to be collected on their behalf to fund these works. The Council currently owns and maintains: The land drainage schemes which have a replacement value of approximately $15.6m (excluding land value). Overall there are 646 km of drains1, 49km of stopbanks, 92 floodgates and control gates, and 4 pump stations. The Flood Protection schemes have a replacement value of $7.4m (excluding land value). Overall there are 37.7km of stopbanks and 16 floodgates, and one pump station. In November 2010 Kaiaua area was incorporated into the Hauraki District. One small land drainage district (Taramaire Drainage District) was transferred to Hauraki District Council. This drainage district is essentially locally managed, but administrative support is provided by the Council. 1 As per the 2011 Infrastructure Valuation 140 2012-22 Hauraki Long-Term Plan – Volume 1 of 2 Map of Hauraki Land Drainage Districts and Flood Protection area Taramaire Flood Protection Komata North Western Plains Opukeko Eastern Plains Tirohia Rotokohu How does this activity promote sustainability? The focus of the Land Drainage activity is sustainable protection of high quality agricultural and horticultural land, and infrastructural services, to ensure on-going social and economic well-being for future generations. It also endeavours to support sustainable principles by mitigating adverse effects from these activities, and promoting a balanced set of well-beings including consideration of environmental, social, cultural and economic benefits in decision making processes. Some ways in which the activity acts sustainably are: Improved education to residents and ratepayers on sustainability and how the Council can help protect the resources of the District. Provision of land drainage, enabling the Plains to be farmed in a manner which provides both for today’s generation and future generations. Control of foreshore and stream stopbanks around Waitakaruru and Miranda. By protecting the area from the tide the Council performs a sustainable practice, as it enables continued habitation, farming practices and operation of tourist facilities. Land Drainage 141 Sustainability Tuner for Land drainage Well-being Dimension What does this mean? The Land Drainage and Flood Protection Group Scale Economic Environmental Social Cultural generally has positive effects on the four aspects of community well-being. This Group of Activities 5 enables farming to continue on the Hauraki Plains. 4 Farming is arguably a cultural tradition and has 3 significant economic benefits, both locally and 2 nationally. This Group of Activities does have a 1 significant negative effect on environmental well- 0 being, including the loss of natural habitat. -1 However, this negative effect is balanced by the -2 positive effects on well-being. -3 For a further explanation of the criteria and how to -4 use the sustainability tuner please see Appendix 7. -5 External issues that affect Land Drainage The capital and renewal works for Land Drainage can be influenced by a number of factors outside the control of the Council. These factors include obtaining resource consents, tender prices, weather conditions, natural disasters, climate change, changes in community expectations and legislative requirements including the Waikato Regional Plan. Capital Works programmes show specific years for undertaking the work, but actual timing may vary as a result of any of the above factors. Climate change and what it means for the Hauraki District Climate change remains a topical issue at an international, national and local scale. The gradual warming of the earth’s surface is associated with polar ice and glacial retreat, more frequent and intense storms, droughts and a rise in sea level. Whilst it is believed that the Hauraki District is unlikely to see any extensive changes in temperature or rainfall averages in the near future, extreme weather events may increasingly affect the District. An increase in the frequency of flooding and/or droughts, increased risk of tidal surges due to sea-level rise, and an increased risk of infestation of invasive flora species are some of the potential outcomes of climate change for this District which could have an effect on the Land Drainage activity. Although the extent of the effects of climate change are still being debated, the Central Government has given local government clear direction (through the Resource Management Act, 1991 and the Local Government Act, 2002) to plan for the effects of climate change. As a result the Council sought community feedback on a range of climate change policy scenarios during the development process of its Hauraki Community

Load more