Farms show 224% better water infiltration, challenging NZ dam-first strategy

Farms under regenerative management have recorded an average 224% improvement in water infiltration rates over five years, according to nine years of data released by āta Verified Regenerative. The figure, drawn from repeat measurements across the company's ecological monitoring programme, is being pitched directly into New Zealand's debate over a national water strategy — and it argues for soil, not just storage.

Dr Hugh Jellie, founder of āta, said a national water strategy that focuses solely on dams, storage and irrigation infrastructure will miss half the equation. Individual farm improvements in the dataset ranged from 42% to 500%.

"With farmers preparing for the possibility of a dry summer, there's understandably a lot of focus on securing water supplies and managing feed," Jellie said. "But we also need to be looking at how effectively our land is capturing and using the water that's already available."

What does this change for farmers?

The short answer: irrigation demand can fall without touching the irrigator.

One dairy farm working with āta has measured a 35% reduction in annual irrigation water applied over three years after adopting regenerative management practices.

The pattern repeats at Lincoln University's Ashley Dene Research and Development Station, where different dairy farming systems run side by side. Ecological monitoring there reported 20% lower irrigation water use on the Integral Health Farm compared with the conventional system.

For farmers weighing infrastructure investment against land management change, that's a meaningful comparison. It's also cheaper than concrete.

Soil as a system, not a sponge

Jellie's argument rests on the connection between water and everything else happening underground. Water cycling doesn't operate in isolation; it depends on plant growth, root systems, soil biology and nutrient cycling.

"When those processes are functioning well, we can make much better use of rainfall and irrigation water," he said. "When they deteriorate, simply applying more water is ineffective and can contribute to further land degradation."

The mechanics are unglamorous. Living ground cover protects soil from erosion and moisture loss. Healthy root systems and soil organisms build the structure and pore spaces that let water infiltrate rather than run off. Improve those processes, Jellie said, and farms build resilience to both ends of the weather spectrum — dry spells and heavy rainfall alike.

One caveat worth underlining: results vary with soil type, climate and land management. A 224% average is not a guarantee, and nobody in this dataset is claiming otherwise.

Nine years, 245 farms, 500,000 hectares

The scale behind the numbers is substantial. āta has spent nine years monitoring ecological outcomes across approximately 245 New Zealand farms covering more than 500,000 hectares.

Its Ecological Outcome Verification programme tracks four interconnected ecosystem processes:

• energy flow
• mineral cycling
• water cycling
• community dynamics, including biodiversity and succession

Notably, the programme doesn't prescribe practices. No mandated grazing rotations, no approved-inputs list. It uses monitoring results to help farmers make their own management decisions and to assess, with data, whether the ecological health of their land is actually improving.

That outcomes-based design is deliberate, and Jellie believes it should shape how the national water strategy is built. Measure whether land is improving, rather than dictating how farmers farm, and the policy follows the evidence.

Why infrastructure alone won't fix it

The timing of āta's intervention is pointed. With a dry summer possibly ahead, attention has turned to securing water supplies and managing feed — the classic storage-and-supply conversation. Jellie's data suggests the conversation should widen.

Rainfall and irrigation water only have value if the land can absorb and use it productively. Water lost through runoff is water paid for and wasted, whether it fell from the sky or came through a pivot.

Jellie's findings show improving the ecological function of farmland is fundamental to effective water management — not a nice-to-have bolted onto the infrastructure plan.

What to watch next

The question now is whether the government's water strategy picks up the monitoring-led, outcomes-based approach āta advocates. Farmers watching the dry summer ahead should also watch the Ashley Dene comparison trials, where the irrigation gap between regenerative and conventional systems continues to be measured.