Mr Martin said water race licences were first issued to gold miners by the Wardens' Court in the late 1800s but purchased by the Public Works Department in the 1920s for irrigating farms, then privatised in 1989.
Mr Martin said a proposed bore or "gallery" system replacing the water races was designed to achieve reliability of irrigation while also providing "greatly improved river low flow conditions".
The new system would spell the end of the two main water races - Tarras and Ardgour - and the Beggs-Stackpole and Rutherford races.
Mr Martin said the new bores would be placed as close to the area of their intended use as practicable.
The gallery system held "unique complexity" because it replaced an old scheme owned and operated by a single company able to ration water with one consisting of individual water resource consents, Mr Martin said.
The LCG is offering to manage the new gallery system which would require a five-year "transition" period to allow many private investment decisions to be made.
"Final design detail and construction cannot proceed until farmers and their bankers have reasonable certainty about the availability of water," he said.
"They need to know the minimum flow parameters and resource consent conditions."
During cross examination, Otago Fish & Game lawyer Maree Baker-Galloway raised questions over water-sharing controls of those Lindis irrigators not part of the LCG.
Mr Martin said regulatory controls would be the responsibility of the ORC but, as well, the Lindis community had "an unparalleled will" to work together.
Department of Conservation lawyer Pene Williams, in her opening remarks, said the gallery scenario "better sustains the life-supporting capacity of the Lindis River's aquatic habitat" and the department supported the LCG's appeal which calls for a summer minimum flow of 550 litres/second in combination with a primary allocation limit of 1639 litres/second.
