Securing agreement for its desired environmental water flows in the new Murray-Darling Basin Plan, "is like winning the Olympics" for South Australia but now the hard work must begin to implement the plan, a CEDA forum has heard in Adelaide.

The historic agreement to allow the Commonwealth to manage water flows across state boundaries came into effect at the end of November 2012 after 10 years of fierce negotiation, surviving a last minute motion of disallowance in the Australian Parliament.

SA Minister for Water and the River Murray, Paul Caica said the South Australian Government had lobbied very hard for the commitment to return 3200 gigalitres (GL) of water to the river system rather than the 2750GL initially proposed.

"Throughout this (negotiation) process the South Australian Government has been unwavering that we need a plan; we need a plan that's based on the best available science and a plan that returns a minimum amount of water to develop a healthy river system," Mr Caica said.

"It is absolutely crystal clear that the Murray River water resources have been over-allocated and this is the cornerstone issue to be addressed through the Murray-Darling Basin Plan," he said.

Upstream states took 93 per cent of the Murray-Darling surface water, leaving South Australia with just seven per cent in total - with only one per cent for Adelaide, Mr Caica said.

While critics claim the scheme prioritises environmental flows over agricultural production, Mr Caica said the environmental flows would underpin the future of irrigation industries.

The forum heard that although NSW and Victoria "were not ecstatic" about the new Sustainable Diversion Limits (SDLs), the deal would:

• Provide agreed minimum flows across jurisdictions to protect the river from erosion and salinity during the next dry spell;
• Set new SDLs with a benchmark for water recovery of 2750GL but an agreement to ultimately deliver 3200GL;
• Establish rules for a water trading system to ensure water is allocated to its most productive use;
• Deliver $1.57b in new Commonwealth funding to assist in recovering water for the river system; and
• Address key constraints on water delivery to flood plains.

Mr Caica said much work remained to ensure that states implemented the new SDLs through their water resource or allocation plans by 2019.

"It's not a time to be complacent...we need to ensure we don't drop the ball on implementation and in delivering the plan," Mr Caica said.

SA Premier's Murray-Darling Basin Taskforce, Chief Executive, Scott Ashby, said guidelines and evaluation frameworks were being drafted to measure the plan's effectiveness in achieving a healthy river environment as well as productive, resilient industries and communities.

Developing clear rules around water trading would also be critical to the Plan's success, Mr Ashby said.

"This is actually a long term plan...The SDLs don't come into effect until 2019; (the plan) is funding projects out to 2024 and the benefits of those projects will flow on for many years,"  he said.

"You do need to think about this as a long term program and many of those measures will take many years to design, construct and implement."

The forum also heard:

• The Plan includes a suite of measures including removing constraints on water delivery to flood plains by raising low bridges and increasing dam outlet capacities, as well as complementary environmental and regional development projects to diversify industries along the river system;
• The Murray-Darling Basin Authority had established the flows required to meet critical human needs in communities along the river and had secured agreement for plans to preserve water as the system started to dry up; and
• Significantly, the Plan would aim to achieve its goals without forced reduction in water allocations, with the Commonwealth investing in infrastructure to reduce water loss and purchasing water allocations from willing sellers.

"South Australia has a great outcome here, not only for South Australia but for the basin as a whole and I do believe as Mr Burke and the Premier have said, this is a once in a generation opportunity," Mr Ashby said.

"Now the challenge for us is to pick this up and implement it as effectively as we possibly can."