New Zealand has over 50 native freshwater fish, and several sports fish. Around 70% of our native fish are Threatened or At Risk.
Many of our iconic native fish species, such as whitebait and eels, need to move between the sea and rivers to complete their lifecycles.
They also migrate upstream and downstream between different habitats within freshwater.
If these movements are delayed or blocked completely, fish may be unable to reach critical habitats for completing their lifecycle. As a result, their numbers can be reduced, or they may be lost from a stream completely.
Fish passage barriers
We have changed our rivers. Structures, such as tide and flood gates, road crossings, culverts, weirs, fords and dams, are commonly found in streams and rivers throughout New Zealand.
If they are not installed correctly they can obstruct fish migrations to upstream and downstream habitats. Fish can also be sucked into water intake structures that do not have suitable fish screens.
Who manages fish passage
DOC and regional councils have specific responsibilities to manage fish passage in our waterways under the Freshwater Fisheries Regulations 1983 (FFR) and Resource Management Act 1991 (RMA) respectively.
Under the FFR, culverts and fords, and dams and diversion structures in any natural river, stream or water may need approval from DOC.
- Culverts and fords may not impede fish passage, unless that impediment has been approved or exempted by DOC. That requirement applies to newly built and existing structures that do not already have an approval or which can no longer meet the requirements of the approval (eg, because the river has changed). Culverts and fords must be maintained by the occupier to prevent the development of fish passage barriers, unless removed or exempted.
- All proposed or built dams and diversion structures built after 1 January 1984, may require a fish facility, and set conditions on their design and performance, excluding;
- any net, trap, or structure erected and used solely for the purpose of taking or holding fish
- any dam constructed on dry or swampy land or ephemeral water courses for the express purpose of watering domestic stock or providing habitat for water birds
- any water diversion not being incorporated into or with a dam, that is solely and reasonably required for domestic needs or for the purposes of watering domestic stock and that empties, without dead ends, into any viable fish habitat
- any dam or diversion structure subject to a water right issued under the provisions of the Water and Soil Conservation Act 1967 (prior to 1 January 1983) or any structure authorised by a Regional Water Board not requiring a water right that in no way impedes the passage of fish. This Act was the primary legislation governing the use of water resources prior to the enactment of the RMA 1991.
- Approval is required for any person to make a structural change to a fish facility
A fish facility means any structure or device, including any fish passage or fish screen inserted in or next to any water course or lake, to stop, permit, or control the passage of fish through, around, or past any dam or other structure impeding the natural movement of fish upstream or downstream.
Under the RMA, regional councils control environmental effects relating to the construction of structures. Rules implemented in regional plans include consideration of fish passage and protection of areas that are important habitats for indigenous fauna.
In addition to specific fish passage requirements it should be noted that there are other statutory requirements that need to be considered in any proposals for the development and management of physical structures (see page 161 of New Zealand fish passage guidelines (PDF, 8,700K) for some examples).
See Fish passage authorisations to apply for:
- an exemption from requirement to maintain a culvert or ford to allow fish passage
- to construct a dam or diversion structure, or
- modify an existing fish facility.