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Opitonui Stream Suspended Sediment Analysis

TR 2005/45
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Report: TR05/45

Authors: Michelle Wild, Murray Hicks (NIWA)

Abstract

Over recent years, there have been concerns that suspended sediment (SS) from Opitonui Stream has impacted on the water quality of the Whangapoua Estuary. As a result, since 1991 Environment Waikato have sampled suspended sediment in the Opitonui Stream downstream of the Opitonui and Awaroa stream confluence to monitor the changes in sediment supply upstream of the confluence. The National Institute of Water and Atmospheric Research (NIWA) have analysed the data to assess whether any significant change in suspended loads and concentrations in the Opitonui catchment has occurred since monitoring commenced; determine whether forest harvesting has contributed to the change; and expand any findings to other sub-catchments in the Whangapoua catchment to estimate relative suspended sediment contributions from these streams. Also, NIWA advise on future monitoring for the Opitonui Stream and Whangapoua catchment.

Opitonui Stream Suspended Sediment Analysis [PDF, 1.1 MB]