Environmental monitoring technical reports

Monitoring and reporting on the state of the regional environment is a core activity for the Council.

Freshwater ecological health

Ecological health is assessed using an internationally recognised index based on tiny animals – including insects, crustaceans, molluscs, worms and leeches – called macroinvertebrates. The index is called the Macroinvertebrate Community Index, or MCI. The Council uses the MCI at 59 key sites on 26 rivers and streams.

Freshwater ecological monitoring 2016-2017 (5.9 MB pdf) Earlier reports

Freshwater physical & chemical state

Physical and chemical ('physicochemical') measurements are used to assess pressures on the health of rivers. The measures include bacteria levels, water clarity, conductivity and acidity (pH levels), nutrient levels, dissolved oxygen levels and the amount of oxygen consumed in the breakdown of organic matter. In all, there are 13 individual measures, which the Council now monitors at 13 sites.

Freshwater physicochemical monitoring 2016-2017 (3.3 MB pdf) Earlier reports

Periphyton (algae)

Algae (periphyton) provide much of the food/energy for aquatic ecosystems. But excessive algae has adverse effects on aquatic habitats and aesthetics. The Council monitors long strands (filaments) and mats of periphyton at 21 sites.

Periphyton monitoring 2016-2018 (4.6 MB pdf) Earlier reports

Rocky shore

Lake Rotorangi

The Council monitors the water quality and ecological health of Lake Rotorangi, which was formed when the Patea hydro scheme was established on the Patea River at Hurleyville in the 1980s.

Annual report 2015-2016 (2.9 MB pdf) Earlier reports