The stream channel is being mapped with the use of a Trimble Pathfinder GPS system, providing an accuracy within 2 m, exceeding the accuracy required for the finished product. In areas where GPS measurement is not reliable, bearing and range are taken until GPS positions can be recorded again.
Points are recorded at the beginning and end of the survey (Start Point/ End Point), wherever features that impact fish migration are present (Feature Points) (e.g. tributaries, culverts), location points to represent changes in the stream course (Location Points), and wherever cross-sections of the riparian zone are taken (Cross-Section Points).