Conservationists fear a government plan to double groundwater extraction from the Martuwarra Fitzroy River catchment in Western Australia could jeopardise threatened sawfish populations. The untamed river, which flows 700km through the Kimberley to King Sound, is considered the last stronghold for sawfish globally and is home to four of the world’s five species. Sawfish, a type of ray named for their chainsaw-like snouts, are “probably one of the most unique looking animals on the planet,” said Dr Leonardo Guida, from the Australian Marine Conservation Society. The river, its estuary, and near-shore marine environment are home to largetooth, dwarf, green and narrow sawfish, all protected under national environment laws. Endangered largetooth sawfish – the largest and most imperilled – are born at the river’s mouth. The young spend several years inhabiting the river, its tributaries and deep aquifer-fed pools, before heading out to sea. Adults can reach up to seven metres in size. “What makes the Fitzroy rRiver incredibly special and unique from a sawfish perspective is that it is the baseline, not just in Australia, but globally of what a relatively untouched sawfish population looks like,” Guida said. But a state government proposal to increase the groundwater allocation from about 32GL to 75.7GL has raised concern among environmentalists and communities. Groundwater aquifers supply several large pools and wetlands that act as crucial refuges for sawfish and other species during long dry periods. “The underground water stores that feed these refuge pools are absolutely critical in a landscape that’s so hot and dry,” said Martin Pritchard from Environs Kimberley, which works to protect nature in the region. “Sawfish won’t survive without these pools, which also provide life support for barramundi, a whole range of other fish, freshwater prawns, and big trees and vegetation that sustain birds, possums, bats and insects. “We’re really concerned that the current proposal by the government is way too much and could cause significant damage to the river and the groundwater-dependent ecosystems.” The WA government’s draft water plan, now out for consultation, has proposed no additional surface water allocations and no dams on the river. Environs Kimberley supported these aspects of the plan, but called for a more precautionary approach to groundwater. Dr Anne Poelina, executive chair of the Martuwarra Fitzroy River Council, an alliance of elders and young leaders from traditional owners of the catchment, said the lived experience of Aboriginal people on country was that the river was already stressed. “Water is precious, it’s a life force, and if living water systems continue to decline it will continue to affect people’s lives and livelihoods as well as the environment, including access to clean drinking water and the rising cost-of living,” the Nyikina Warrwa woman said. Poelina said there were currently too many unknowns – about the connectivity of the system and about how much groundwater there was, and the potential impact of sea level rise – to start allocating groundwater for profit-making activities. Both communities andthe WA department of water and environmental regulation (DWER) needed a longer timeframe to be able gather information before the plan was finalised, or any additional licences given, she said. A similar water allocation plan in the Pilbara had failed, with groundwater aquifers in the region in decline, which didn’t offer much confidence about the plan for the Kimberley. “These are human issues as well as environmental issues – it does not make us confident when the science and lived experience stories of how these systems are changing right now. These are public interest matters. This is going to impact everyone that’s living within this system, we need to proceed with caution and not take risks, with the lives of all Kimberley people and our environment,” Poelina said. The river has national and Aboriginal heritage list status for its outstanding cultural and natural values. Farmers have sought greater access to the river’s surface and groundwater for agriculture and livestock, in various plans dating back to the 1950s. Recent proposals for unconventional gas developments, known as fracking, could also have implications for groundwater resources. Dr Ryan Vogwill, a hydrogeologist said groundwater played an “incredibly important” role supporting the high biodiversity and cultural values of the river ecosystem during dry periods. “In a big wet season, the whole system floods with water and goes all the way to the coast,” he said. “But in smaller years, when there’s not so much rainfall, the river may only flow a little, or may not flow at all. “In those periods when the surface water isn’t flowing and hasn’t flowed for some time, groundwater becomes key to the environment persisting and staying healthy.” Vogwill said interactions between the surface water and different layers of groundwater aquifers were highly complex and more monitoring would help to better understand the system and assess any potential risks – whether from increased use for pastoral industries, or proposals for unconventional gas. Applicants seeking a licence would need to demonstrate “sustainable groundwater use” and “protect water-dependent ecosystems and sites of ecological, cultural and social significance,” according to the draft plan. Guardian Australia asked DWER how the groundwater allocation was determined and whether the government would invest in additional monitoring but did not receive a response.