The advantages of taking irrigation water from a series of bores along the length of the Lindis River rather than from existing water races are likely to be central to the deliberations of Environment Court Judge Jon Jackson over coming weeks.
Judge Jackson yesterday adjourned the hearing of, and reserved the court's decision on, an appeal brought by the Lindis Catchment Group (LCG) and the Otago Regional Council (ORC) against an ORC decision which, among other things, imposed a minimum flow of 900 litres per second for the Lindis.
The LCG is proposing a 550 litres per second minimum flow and the replacement of water races with the bores - referred to as ''galleries''.
It contends it would be uneconomic for irrigators to develop the gallery system if the 900 litres per second minimum flow limit remained.
Presenting almost 100 pages of evidence to the hearing, resource management planning consultant for the LCG Sally Ann Dicey said the 550 litres per second minimum flow was ''crucial'' to enabling irrigators to have sufficient reliability of supply.
She submitted the changes proposed by the LCG, including shutting down the large irrigation races and reducing allocation, would bring ''positive benefits to instream flows and associated values''.
Ms Dicey said compared with the existing regime, the LCG's proposal ''will result in enhancement to in-stream ecology, natural character, amenity, cultural [and] recreation values'' while farms would be ''likely to stay financially viable''.
And compared to the ORC's decision, with a minimum flow of 900 litres per second and the continuation of the races, the LCG's proposal would result in ''better outcomes for in-stream ecology, natural character, amenity, cultural and recreation effects and economic and social wellbeing''.
The Otago Fish and Game Council has indicated the gallery system would be better for trout than the water races, but has maintained the 900 litres per second minimum flow is needed so trout can migrate upriver over summer, when the lower reaches usually dry up.
The consultant planner for the council, Frances Lojkine, told the hearing in her written evidence the 900 litre per second minimum flow would lead to more water in the river and ''therefore in my opinion has a better chance of meeting the requirements of the national policy statement for fresh water management and the Resource Management Act''.
And, she said, ''it would not be appropriate to grant consents with the minimum flow of 550 litres''.
''Even if consents were to be granted with a minimum flow of 900 litres per second, a further process of phasing out over-allocation would be necessary.''
Resource management consultant for the ORC Brent Cowie supported, subject to conditions, the LCG'S suggestion of allowing a ''pulse'' of water down the river to help the migration of juvenile trout when the river level was low for a period of time.
Before adjourning, Judge Jackson gave lawyers a ''grab bag'' of questions still requiring answers.
