Benchmark vertical datum is Lyttelton Vertical Datum 1937.The river benchmarks layer shows the location of survey
benchmarks used by the Council to monitor riverbed elevation change. These
benchmarks are protected by the Flood Protection and Drainage Bylaw, any work
proposed around these locations should be checked with the Environment
Canterbury River Engineering team prior to commencing. Most of these are iron
rods that are buried beneath the surface and will need specialist equipment to
be located.
