Ms Ruru and Associate Prof Richard Troughton, of Otago University's Christchurch campus, are the latest recipients of the university's Rowheath Trust Award and Carl Smith Medal, which recognise outstanding research performance by Otago early-career staff.
Ms Ruru's Carl Smith Medal lecture this week was on the topic "Undefined and unresolved: Maori legal rights to water".
After a wide-ranging talk, she concluded "while Parliament and the courts have not yet recognised Maori ownership of freshwater, it is well accepted as a live issue".
"While advancement has certainly occurred with the recently-enacted Treaty of Waitangi claim-settlement statutes geared towards co-governing water, the overall impression of water management in this country is still one of mono-cultural decision-making."
The Government had acknowledged Maori rights and interests in the matter were "undefined and unresolved", she said.
"The defining and resolving of these legal rights is a great legal challenge facing us right now."
Water was essential for the welfare of people, plants, livestock, farming activities, industry and power generation and had been termed an "essential resource" for New Zealand's economic, environmental, cultural and social wellbeing .
A recent Government-commissioned Land and Water Forum report had also stated water was a "taonga [treasure] which is central to Maori life".
Maori law had developed through the centuries to create strong rules for protecting the mauri (life force) of water, and it was "abhorrent" to mix waters from different catchments or with human sewage.
When Maori groups opposed water-related consents under the Resource Management Act they had some wins and partial wins. But a review of such court decisions showed "Maori are more likely to lose than to win".
The issue of Maori and water was "at the forefront of the Waitangi Tribunal right now", and had come to a head through "the proposed partial sale of four state-owned enterprise energy companies.
There were several options for discussing a "reconciled solution" to Maori contestation of "Crown assumed and asserted ownership of natural resources, including water".
One possibility was to proceed along the lines of a whenua topu trust, that could be established by the Maori Land Court, in respect of any Maori land or general land owned by Maori, to facilitate the use of such land in the interests of the iwi and hapu.
Such a trust could perhaps be extended to water, and the trust deed "could easily ensure the water is unalienable and public access, for the most part, is guaranteed", she said.
