Keeping an eye on river quality
Environmental Monitoring Officer Michael Rogers checks the Wakamarina River sensors.
Council has installed sensors at strategic sites in the Te Hoiere/Pelorus River catchment to allow continuous monitoring of turbidity.
This allows investigation of sediment inflow into Havelock Estuary from the Te Hoiere/Pelorus, Rai River, Wakamarina and Kaituna rivers.
Turbidity is a proxy measure for sediment in the water column. When paired with flow measurements and sediment sampling, continuous turbidity monitoring enables the calculation of sediment loads and enhances understanding of sediment dynamics, according to Senior Environmental Scientist Steffi Henkel.
“This knowledge is essential for determining appropriate mitigation measures to reduce sediment inputs,” she said.
“The Wakamarina site needed the most extensive installation work. It included setting up turbidity monitoring and the establishment of a new flow monitoring site, consisting of continuous water level recording and a number of flow gauges to establish the relationship between water level and flow.
“As a major tributary, the Wakamarina’s flow data is also important for understanding flow contributions within the catchment particularly during flood events.”
The installation of turbidity sensors marks the first phase of the project. The second phase, currently under development, involves specialised sampling of the water column during different flow conditions.
This will help establish the relationship between turbidity measurements and actual sediment concentration and distribution.
