The Government's long-awaited package of freshwater reforms dropped this morning, with tougher rules for farmers and higher bars for water quality. Science reporter Jamie Morton looks at why they were needed, what they mean, and how interest groups have responded.
How have our lakes and rivers been faring?
Across the board, not well. But trends tend to vary depending on what measure is looked at.
Levels of E.coli - the notorious bacteria linked to animal or human faeces that can leave swimmers suffering vomiting, cramping, nausea and diarrhoea - aren't going up or down at most sites.
But, when compared with the relatively unspoiled waterways that flow through our native wilderness, levels are 22 times higher in towns and cities.
And they're nearly 10 times higher in the pastoral countryside that wraps around much of New Zealand's 180,000km of total river length.
Just as important - if not more so - are two key nutrients linked to farming intensification.
Nitrogen and phosphorus come from livestock waste, fertiliser and eroded soil, as well as septic tanks and sewer systems.
If too much enters waterways - whether by leaching through the soil or being washed off roads and paddocks - algae can grow in large amounts.
This triggers a cascade of problems - notably decreased oxygen levels and reduced light - which can hurt or kill species, and fuel toxic blooms.
The latest Government stocktake showed that between 1994 and 2013 - a period that saw an explosion in cow numbers amid dairy's white gold rush - levels of nitrate-nitrogen in monitored rivers were getting worse (55 per cent) at more sites than were improving (28 per cent).
On the flip side, rates of dissolved reactive phosphorus were improving (42 per cent) at more sites than worsening (25 per cent).
When it comes to lakes, a recent five-year grading of 65 lakes using a catch-all trophic level index, showed 24 sites had good or very good scores, the same number had poor or very poor scores, and the rest were rated moderate.
All the while, three quarters of our monitored native fish species are now nearing extinction.
Nearly all of our natural wetlands have been wiped out, along with an untold number of plants and animals that depended upon them.
Cleaning up waterways has long been singled out as a target area for the Government, which has budgeted $229m to help reach its goal of turning the picture around within a generation.
But today was the day it told Kiwis how it wanted to get there.
So what's been announced?
The current centrepiece of our national legislation around freshwater has been the National Policy Statement (NPS) for Freshwater, introduced by the previous National-led government.
An overhaul of that rulebook for regional councils is among a raft of proposals in the just-announced action plan.
Yet, arguably the boldest would come with a new and entirely separate rulebook.
The National Environmental Standards for Freshwater (NES-FW) would effectively put the brakes on further intensification of dairy farms.
Under this, landowners wanting to convert to dairy or open up new irrigation would have to first prove there would be no increase in pollution.
That "interim" restriction, proposed from next June, would stay in place until 2025, when councils were expected to have set up new standards under the new National Policy Statement (NPS) on freshwater.
Also under these standards, farmers and growers would need to have a farm plan to manage risks to freshwater by 2025.
Farms in catchments with high rates of nitrogen loss would need to bring nitrogen levels down – by as much as 80 per cent - within the next few years.
A requirement to keep all stock out of waterways more than a metre wide would mean more fencing.
There would be fresh standards around winter grazing, feedlots and stock holding areas, with "sacrifice paddocks" required to be at least 50m from waterways.
Under the overhauled NPS, the health and wellbeing of water would be put first in decision-making, and providing for "essential human needs", such as drinking water, would come second.
The new rules would put a halt on any further draining or development of wetlands, and remaining streams in urban and rural areas would not be piped or filled in unless there was no other option.
River ecosystems would be better monitored and measured by an expanded range of indicators – among them, nutrients like nitrogen and phosphorus, sediment, fish and macroinvertebrate numbers, the amount of native, ecosystem metabolism, and dissolved oxygen.
There would be a higher standard for swimming in summer – specifically, 540 colony forming units of E. coli per 100ml at popular spots, which councils would also be required to better manage.
Elsewhere in the package, the Government proposed another new set of rules for wastewater discharges, which would set minimum treatment standards.
An accelerated planning process, already built into the Resource Management Act amendments, would push councils to make better, faster and more consistent freshwater management plans.
Councils expected the proposals would generally sharpen up policy tools, and help deliver what communities wanted for their environments.
"However, getting the detail and timeline settings right will be critical," Local Government New Zealand president Dave Cull said.
"We need to set our urban and rural communities up for success by right-sizing the new regulatory requirements and the deadlines so that they can meet them."
Cull argued the pace of freshwater change could ultimately only go as fast as a community's ability to pay.
"This is particularly so when you consider the tsunami of regulatory costs that rural and provincial areas are staring at, as well as ageing infrastructure such as storm water and waste water treatment plants across the country."
How have farmers reacted?
Predictably: with serious worries and questions.
Influential lobby group Federated Farmers went as far as arguing that New Zealand would have to abandon its reliance on the pastoral sector – and that the proposals would lead to wholesale land use change to meet what it called unnecessarily stringent targets.
"It becomes very hard to continue economically farming animals or growing vegetables under a regime like this," its environment and water spokesperson Chris Allen said.
"The long term targets for nitrogen reduction, are effectively unachievable in some parts of the country, and will end pastoral farming in these areas."
The group said while it was supportive of government efforts to improve water quality, the reforms went too far.
"Lumping regional councils, with an entirely new regulatory system to implement and manage puts up everyone's rates, and gives little additional support to actual water quality results," Allen said.
"Millions of dollars raised from increased rates which could have been spent on more river and waterway restoration will now be spent on hearings, lawyers and other random water experts.
"Basically your rates will go up, while farmers are doing the work anyway."
The group was particularly worried about the proposed interim measures to clamp down on intensification, instead labelling it a ban that stopped landowners doing something with their property.
DairyNZ boss Dr Tim Mackle said his sector acknowledged water quality in some catchments had fallen short of community expectations – but he argued against a blanket, one-size-fits all approach.
His group also had concerns that the proposed approach of reducing nitrogen and phosphorus might not achieve improved ecosystem health and could have a significant impact on the viability of farm businesses and rural communities.
"We need to understand this better and what it means for our water quality, farmers and for the country."
Beef + Lamb New Zealand chairman Andrew Morrison claimed that plans to lock down current land uses would have a disproportionate effect on the majority of sheep and beef farms that were low input, extensive systems.
Morrison pointed to modelling that suggested 68 per cent of drystock farms in the Waikato/Waipa catchment would be converted into forestry as a direct result of the proposed regulations, while more intensive land uses largely remain the same.
"These proposals will undermine the viability of a low-intensity sector which supports over 80,000 jobs and generates exports of $9.1b a year," he said.
"Ultimately, we are concerned the sheep and beef sector will bear a disproportionate impact of the proposed policies, far outweighing the environmental impact of our farming systems."
What about green groups?
They're welcoming it, albeit cautiously.
Forest & Bird's Kevin Hague said while there were many details to be worked through, he backed the programme's overall intent.
"The Government set aside almost $300m in the Budget to help farmers transition to environmentally-friendly practices, but we also need strong rules to prevent the worst practices," he said.
"Report after report has shown the major driver of our freshwater crisis is intensive agriculture, but the current rules allow too many cows, too much fertiliser, and continued wetland destruction.
"To protect what we love, we need strong rules - no more half measures."
Environmental Defence Society chairman Gary Taylor expected some of the proposed measures would work and some wouldn't.
"Where there are important choices to be made after public feedback, the options include continuing with elements of industry self-regulation or moving towards stronger central and regional government regulation," he said.
"These deal with winter grazing, excessive nitrogen and whether freshwater modules in farm plans should be mandatory.
"The industry-led approach hasn't worked to date and should be firmly rejected. The NES-FW will need close scrutiny in this respect and weak options should be weeded out."
Overall, he said, the reform package on offer would lead to big improvements in freshwater quality if the stronger options were preferred at the end of the process.
"The interim measures can stop things getting worse and deal effectively with high risk land use activities."
Taylor backed the suggested establishment of a Freshwater Commission to provide oversight.
"That is the key structural change that is required: a dedicated specialist entity with wide-ranging powers to ensure regional councils perform."
That proposal was also supported by Fish & Game New Zealand, whose chief executive Martin Taylor summarised the wider package as having some good options - such as the 2025 deadline for farm plans - but only if they were picked.
"However, we have concerns regarding a number of bad options around industry set standards and enforcement. These need to be rejected," he said.
"The reality is that some intensive dairying operations are heavy polluters who do not want strong, mandatory rules because they want to maximise profit margins."
Taylor saw the NES as a way to "hold the line" and stop degradation getting worse now, while the NPS was about delivering better water quality down the line."
He added a recent poll commissioned by his group showed that two thirds expected the Government to set rules to protect water quality – and three quarters were either "extremely or very concerned" about the pollution of lakes and rivers.
"This is a once-in-a-generation opportunity to tackle an issue Kiwis are deeply concerned about. Let's get this right."
Greenpeace thought the Government should go further and put a sinking cap on synthetic fertiliser use.
And what do scientists say?
Niwa's chief freshwater scientist, Dr Scott Larned, described the package as ambitious – and probably challenging for councils and land and water users to implement.
"But it may be exactly what is needed to initiate or accelerate large-scale improvements in freshwater environments."
Larned said the proposed inclusion of multiple ecosystem indicators could improve how our waterways were protected – but more work was needed to ensure these were measured accurately.
Professor Richard McDowell, the chief scientist of the Our Land and Water National Science Challenge, expected regulation of some farm practices like fencing and grazing of winter forage crops would go some way towards "correcting" what has been missing in existing policy documents.
"We will have to see the result of consultation and assessments of what's practical to see if they go further," he said.
"For example, we know the majority of contaminant loads come from small streams, but fencing them off may not be the most practical nor sensible when other mitigations in headwaters are probably more cost-effective.
"We also know that 10 per cent of a farm in winter forage cropping contributes 30 to 40 per cent of the nutrient load, but suspect that this proportion may be greater if winter forage cropping is practised on floodplains."
He was encouraged at the move to require farm plans.
"We know that identifying critical source areas on a farm and targeting them with practices to mitigate contaminant loss is much more cost-effective than an untargeted approach," McDowell said.
"We've also recently calculated that if all known mitigations are implemented nationally by 2035, we will reduce nutrient and sediment losses by 30 to 60 per cent."
Iain White, a professor of environmental planning at Waikato University, also saw a lot to like in the proposals.
"It's catchment wide and inter-generational, which better reflects the scale of the problem and the length of time it may take to transition to a more sustainable relationship," he said.
"While a focus on shared responsibility reflects the reality of the situation, it also links to the practical political difficulties in aligning decision-making around a shared vision when this is such an intensely political issue."
• People can have their say on the proposals here .