Environmental flow investigations
MidCoast Water Services has completed investigations into environmental flows in the Manning River to ensure that our pumping operations at Bootawa for the Manning Water Supply can be managed with no negative impact on the river itself. The work included studies of Australian Bass, Platypus, and Ribbon Grass distribution in the upper estuary.
Why are environmental flows important?
Environmental flows assess the volume of water needed in a river to maintain the health of the ecosystems which rely on it. In the Manning River the water level can be affected by natural processes such as droughts and floods, but also by human activities like extraction for irrigation and drinking water. Potential problems when flow is very low include an inability of fish to migrate up and downstream for food and spawning (see schematic on right); animals like platypus becoming more exposed to predators when they forage and travel; and the intrusion of salty water from the ocean in to the upper estuary (around Wingham) where it kills ribbon grass, very important fish habitat.
The NSW Department of Primary Industries - Water has used some of MidCoast Water Services' information, along with their own, to develop a water sharing plan for the region.