Calls are being made for a clearer plan towards achieving the Government's water target.

Improving urban water waste management and farming practices are key focuses in making 90 per cent of waterways swimmable by 2040.

But Local Government New Zealand chief Malcolm Alexander said the Government needs to engage with the people on the ground for the plan to work.

He said people have to know what's required of them.

"Connecting the environmental debate with the on the ground debate about how this is going to be delivered. Unless we're all across it, and understand what's going to be required, this will not end well."

The plan to get the waterways in a cleaner state is going to cost $2 billion.

Mr Alexander said the cost will require extensive financial planning.

He said urban change is just as important as rural.

"The necessary upgrades that are going to be needed to wastewater systems, storm water etc and those are just as important as agricultural production is."

A key part of the plan is fencing all cattle, pigs and sheep off from waterways.

The required fences are set to cover more than 56,000 kilometers.

Federated Farmers said it welcomes the ambitious plan even though it will create capacity issues.

Its board member Chris Allen said the plan's not perfect and the Government should help farmers cover the costs.

"When we exclude stocks from waterways it means buying troughs. It's a huge investment and the government needs to acknowledge half the cost of exclusion."

Mr Allen said many farmers have already dedicated huge amounts of their money and time into making that happen and it's time communities got on board.

"The dairy industry, through a voluntary approach, has fenced off a huge number of waterways. [It’s] got the sheep and beef industries doing a huge amount of work."