Determination of mean high water mark within New South Wales

Abstract

The boundary between water and land is one of the most ancient boundaries used by society. Despite the long history of usage, society has found that the land/ sea zone is not a definite boundary. The influences on a tidal boundary are many, from gravitational and centrifugal forces acting on the earth to the many local variations that can shape a tide. From this active interface between water and land, a surveyor must determine a precise boundary. The aim of this project is to develop a system of procedures that will help to define this dynamic boundary. Developing a procedure manual will involve researching and evaluating the current guidelines, regulations and survey techniques used in determining tidal boundaries. This research will allow the development of a system that will guide a land surveyor when determining Mean High Water Mark boundaries along tidal land. These guidelines will be applied to a tidal boundary on the Central Coast of New South Wales, so as to validate the procedures. This project has found that using tidal information collected over a long period of time at a tide gauge would increase the accuracy of determining a tidal plane. By comparing the tidal data of a site that does not have long term tidal data with a control gauge, which does have long term tidal data, a reliable answer can be achieved. Therefore a procedure was developed to guide a surveyor through the determination of a Mean High Water Mark within New South Wales. The procedure manual will introduce a system in the techniques to follow in determining a water boundary. The user of the manual will be aware of the various issues faced in establishing a tidal boundary and this manual will allow them to make the informative decisions. It is recommended that this manual be incorporated into any survey company's quality control management system.