Report: TR 2014/13
Author: M Wood (Wainui Consulting Ltd)
In the Waikato region there are many rural areas that are very flat and have limited natural drainage outlets. Over time, networks of drains have been developed within these areas to provide adequate land drainage to support pastoral farming and to alleviate flooding. Without these drainage networks, these areas of land would be unproductive and inaccessible. Many of these areas have been formalised to constitute land drainage areas.
Waikato Regional Council is responsible for administering many of these drainage areas, and at the time of this report's preparation was responsible for managing and maintaining drain networks within 92 separate areas in the region. Four drainage advisory subcommittees have been established to oversee the management of the drainage areas; Aka Aka/Otaua, Franklin Waikato, Waikato central and Thames Valley. Areas that are not managed by Waikato Regional Council are administered by the relevant territorial authority (TA).
Levels of service have been agreed upon for the drainage areas that relate to their rural use and the drainage requirements that are necessary to ensure the land’s productivity and accessibility without too greater financial burden on those that benefit from the drainage areas.
There are several drainage areas that are located in close proximity to Hamilton and proposed future urban growth within the city means that the extent of the urbanised area is encroaching closer to these drainage areas. The drainage systems in the drainage areas are designed for rural runoff and not for urban (residential and non-residential) runoff. Hence the interaction between urban drainage and the land drainage areas needs to be carefully managed by the TAs and Waikato Regional Council. Hamilton City Council is currently preparing Integrated Catchment Management Plans (ICMPs) for the new urban growth areas within the Hamilton city limits.
This report has been developed to provide background information about the Waikato Regional Council administered land drainage areas and to highlight the issues associated with land use change in close proximity to, and within, the land drainage areas. Discussion is provided about what assessment is required if a proposal is potentially impacting on a land drainage area and a process is mapped out on how to move projects forward in these circumstances.
The report includes the following sections:
|2||Land drainage areas|
|2.3||District council administered areas|
|2.5||Drainage area descriptions|
|2.5.1||Aka Aka drainage area|
|2.5.2||Franklin Waikato drainage area|
|2.5.3||Waikato Central drainage area|
|2.5.4||Thames Valley drainage area|
|2.7.2||Drain, culvert and floodgate capacity|
|2.7.3||Drain, culvert invert levels|
|2.7.5||Key operation issues|
|2.10||Review of land drainage areas|
|3||Land use change|
|3.2||Hamilton urban growth|
|3.3||Rural residential land use change|
|4.2||Scale of proposed development|
|4.2.1||Information requirements for small scale subdivision (Category 2)|
|4.2.2||Information requirements for larger scale development (Category 3)|
|Appendix 1: Hamilton future growth|
|Appendix 2: Information requirements for small scale subdivision|