Forecast to mull Rangitata water

Environment Canterbury (ECan) has been given the go-ahead to see whether getting water from the Rangitata River will improve water quality in part of South Canterbury.

Its Orari-Temuka-Opihi-Pareora (OTOP) Zone Committee has approved the forecasting exercise and it is set to begin soon.

The first ‘‘business as usual’’ scenario would have ECan scientists predict water quality and quantity within the zone if nothing were to change. The second would forecast where the zone was heading and how that might change with additional water coming in.

Water from the Rangitata River ‘‘looks like a viable option’’, ECan senior hydrology scientist Dan Clark told the zone committee this week. Details as to how it would work, and where the water would be introduced, were unavailable at the outset of what would be a forecasting exercise.

Forecasting each scenario could help the determine what was needed to achieve the aims of the OTOP healthy catchments project.

The scenarios would be developed and assessed by scientists against the outcomes they would help the zone to meet.

By way of example, Clark told the committee the scenario may consider how new water in the catchment would affect minimum flow levels.

It may also consider how the water flow forecast would affect discrete ecosystems, such as whether invertebrate communities might grow.

The zone committee would hear the outcome of the exercise later this year. It was likely some outcomes would be ‘‘met and acceptable’’, while others ‘‘would have people saying no way’’, Clark said.