The Ōtaki River catchment drains about 400 square kilometre of the steep western slopes of the Tararua Ranges -- an area stretching from Mount Aston in the south to Mount Pukematawai in the north.
The river is joined by two major tributaries at Ōtaki Forks and flows through deep valleys and gorges in the foothills to the coastal plain, where it meanders to the Tasman Sea between Te Horo and Ōtaki townships.
Human influences on the floodplain, such as forest clearance, urban settlement and some river management practices, have resulted in significant changes to the landscape. These changes, combined with natural floods, have created a flood hazard. Even with the protection that was put in place between 1945 and 1955, following a series of floods during the 1920s and 1930s small to medium-sized floods continue to cause damage. This problem has been made worse by recent settlement, which has been located in areas susceptible to flooding.
We oversee river management activities including gravel extraction, erosion prevention and repair works, and maintenance of stopbanks that have reduced the flooding risk to the Ōtaki community.
To find out flood hazard information about a specific area, please view our GIS maps online: GWRC GIS flood Hazard Areas or here: KCDC GIS flood extents.
The activities undertaken to manage the river are detailed in the Ōtaki Floodplain Management Plan jointly developed by us in conjunction with Kāpiti Coast District Council (KCDC).
Ōtaki Floodplain Management Plan was developed in June 1998 to analyse the problem of flooding, looking at preferred options to mitigate and manage risks, and also look at the environmental and economic impacts. The Plan took six years to develop and remains as a living document, which means it can be reviewed, changed and developed further over time.
Key to implementing the Plan is your continuous involvement, which will keep the Plan alive and will reflect your changing needs as well as keep you informed and prepared.
You can download the plan here: Ōtaki Floodplain Management Plan.
Ōtaki Environmental Strategy, jointly developed by us and KCDC, guides our environmental enhancement programmes in that region. The strategy, developed in 1999, recognises that numerous agencies, community groups and landowners have a role to play in protecting the Ōtaki River and its environs.
To ensure opportunities and priorities for environmental enhancement are consistent and realised, an overall coordination of the different roles of the partners, stakeholders and interested groups are necessary. The strategy, which is a living document that can be reviewed and updated from time to time, is a first step towards providing the overall coordination. Find the document here.
Our operation and maintenance activities in Ōtaki River are carried out under consent. Here is our land use consent form.
This consent has been extended until a new consent is granted.