River Lake has been working with Palmerston North City Council for many years to help understand and reduce the effects of the Tōtara Road wastewater treatment plant (WWTP).

We have undertaken monitoring  of aquatic macroinvertebrates, periphyton, water quality, and diurnal fluctuation in dissolved oxygen. We have also undertaken investigations and experiments to understand river processes.

Learn about the role of nutrients in driving excessive periphyton growth in the Manawatu River, and how periphyton mine phosphorus from fine sediment captured within their mats. Click the link below:

In 2017 PNCC initiated a Best Practical Option (BPO) review of how to improve the treatment and disposal of wastewater in the future. River Lake is part of a team assisting with this process.

Here is our 2019 experimental setup to assess what concentrations of nitrogen are required to control periphyton growth in the Manawatu River.