Some Land Transfer Certificates of Title will record the edge of a stream as the legal boundary. Generally, this will not be a straight line, and there will be situations where the stream bed has become dry, for example where a drain has been cut through a meandering stream. Where the original stream was a non-navigable river, it may be possible for the adjoining land owner to claim a new boundary to what was the middle of the original stream. This is based on a common law presumption that ownership extended to the middle line of the bed of the non-navigable river. The legal principle is encompassed in the Latin phrase usque ad medium filum aquae (up to the middle thread of the water).
It is necessary to make an application to LINZ to bring the land into a new title. The guidelines are set out in LINZG20710 – http://www.linz.govt.nz/regulatory/20711
The position is more straightforward if the applicant owns both sides of the dry stream bed. Public Notice by LINZ of the application is required.
There are some complexities involved in dealing with such an issue, and it will be necessary to engage a surveyor and to seek legal assistance.