Labor's water spokesman Tony Burke is threatening to make rural communities wear the consequences of his dissatisfaction with government progress on the Murray Darling Basin Plan.
This week Mr Burke said the federal Coalition government had failed to properly implement the Basin Plan and take water reform seriously, which had caused an "ecological disaster" in the river system.
"There is no doubt action needs to be taken and it needs to be comprehensive," Mr Burke said.
A new Labor policy document identified infrastructure projects state governments are required to deliver by 2024 under the Basin Plan.
"A Labor Government will strengthen the 2024 reconciliation process and buyback any water required if the projects that aim to deliver 605GL of environmental benefits fail to deliver the full amount of environmental benefits," policy said.
The projects are intended to ease pressure on irrigators by reducing the amount of buybacks by 605 gigalitres, while using infrastructure to deliver the equivalent benefits of water saving to the environment.
Mr Burke said in February new evidence on climate change could create a case to raise the volume of water to be recovered from irrigation under the Basin Plan.
National Irrigators Council chief executive Steve Whan said Mr Burke's threat to ramp-up water buybacks made local communities liable for the actions of state and federal governments.
Commonwealth water buybacks are opposed by many communities and irrigators across the Basin, and fallout from water market reforms has seen the rise of independent and minor party candidates in state and federal politics.
Mr Burke would assume responsibility for the projects from May 18, Mr Whan said.
"It is an insult to the industry and irrigation communities to have, as the only policy comment on those projects, the use of the 'big stick' of water buybacks," he said.
"Rather than focus on what they'll do if the projects aren't achieved, and pretend that someone else has to implement them, Tony Burke should focus on the fact that they would be his job as minister to get those projects get up and running.
"Serious parties, including alternative Governments, need to recognise that we will get much worse environmental outcomes if we destroy cooperation between Governments and communities."
The projects are an element of the Basin Plan designed to increase efficiency of water movement and deliver an equivalent boost to the river and riparian environments, and make space in the river to move increased water volumes without flooding towns.
State governments are responsible for the design and construction of the projects.
Under Basin Plan laws, water buybacks could be used to make up the shortfall if they aren't ready on time.
The projects are well behind schedule and could exceed the 2024 deadline.
In 2015 the Coalition created a new law to cap buybacks at 1500 gigalitres (the limit is yet to be reached).
This week Mr Burke emphasised Labor's preference to use buybacks and reiterated his party's commitment to abolish the cap.
Labor also pledged to invest $120 million for a wide range of initiatives, some new, some announced previously.
It includes an inquiry limited to the 2017 buyback of water from Eastern Australian Agriculture, which was initiated by former Agriculture Minister Barnaby Joyce.
It also pledged to invest $52 to increase water metering and monitoring, an independent review of the Murray Darling Basin Authority, commission CSIRO to re-run its Sustainable Yield study into the Basin, and commission a $26 million study into climate change's impacts, and "crack down" on illegal structure to harvest floodplain overland flows.