Quarterly Water Quality Report – January-March 2024
Opuha Water Ltd publishes its quarterly water quality reports for Lake Opuha and the wider scheme catchment to share with the community the results of our extensive water quality monitoring program. This report focusses on the eDNA monitoring and biomonitoring (periphyton, macroinvertebrates and fish) that has been undertaken in the Kakahu River in March 2024. eDNA sampling was carried out by OWL and the biomonitoring was undertaken by SLR Consulting.
Key Findings
eDNA
- Kōura, freshwater mussels, longfin eel, shortfin eel, upland bully, common bully, Canterbury galaxias, torrent fish and brown trout were all detected in the Kakahu River using eDNA.
- The ecological health of the Kakahu River was rated as either Average or Poor using the eDNA method.
Biomonitoring
- The macroinvertebrate community index (MCI) scores in the Kakahu River were similar, with waterway ratings of Good and Fair.
- The quantitative macroinvertebrate community index (QMCI) scores in the Kakahu River were higher upstream of the discharge point compared with downstream, with waterway ratings of Good and Fair.
- Longfin eel, shortfin eel, upland bully, common bully and trout were caught in the Kakahu River. These fish were identified upstream and downstream of the discharge point.
- SLR Consulting concluded that the collective biomonitoring results from this survey and previous surveys do not indicate any consistent patterns or significant adverse effects of the consented discharge on the freshwater communities of the Kakahu River.
Download the full report here.
