Protecting our water quality

City Forests has worked with the Otago Regional Council to set up an appropriate water monitoring system for key waterways in the company’s forests.  Semi-permanent sample points are established in streams that are adjacent to impending, current, or post-harvesting operations, and are intended to monitor for changes in water or water quality due to harvesting operations.

Attributes assessed are:

• Water clarity (SHMAK rating)
• Water temperature
• Water conductivity
• Any evidence of substrate sedimentation
• Indicator invertebrate species
• Condition of riparian vegetation.

Evidence of monitoring to date consistently shows the benefits of well-managed plantation forests to stream water quality, especially when compared to streams that cross other land uses.  Some of City Forests’ plantations form part of Dunedin’s water catchment network, including Flagstaff and Ross Creek forests, putting further need on ensuring water leaving the estate is of high quality.

Water monitoring for fish species presence is also done prior to harvesting areas where significant waterways exist.  This information impacts potential harvesting timeframes as harvesting must avoid fish spawning season in the case of some species.  This information also contributes towards continually updating the national freshwater species database.