This is the second part of the three-part series Water-Smart Regeneration: Bridging Soil Health and Irrigation Efficiency by Adrian Vargas, RRG NBS Water and Irrigation Expert.

Where Part 1 focused on soil health and on-farm practices, this piece looks at the landscape scale: how we shape landforms, routes, and storage to slow, spread, and sink water. Thoughtful land design turns rainfall from a risk into an asset – capturing water in wet years so it’s available in dry ones, reducing flood peaks, and recharging soils and shallow groundwater.

Why landscape design matters

Water flows across a farm before it becomes irrigation water. If we work with that flow, by observing contours, soil types, vegetation and natural catchments, we can redirect and store water where it benefits crops and ecosystems. Good design reduces erosion, limits nutrient loss, and increases the window of water availability for plants. In an era of climate volatility, these landscape measures act as shock absorbers: they reduce vulnerability to both intense rains and prolonged dry spells.

Keyline design: use the land’s shape to move water

Keyline design is a practical, low-tech way of using topography to spread water outward from valleys toward ridges. The method identifies the “keypoint” on a slope (where the land changes from convex to concave) and then uses contour-parallel cultivation or ripping to encourage lateral flow and deep infiltration.

How to implement keyline design

• Survey: start with a topographic map or a basic contour survey to locate ridges, valleys and the keypoint.
• Design: lay out keylines that follow contour offsets from the keypoint to guide water laterally.
• Implement: use ripping, subsoiling or contour cultivation along keylines; combine with perennial plants to stabilise soil.
• Combine: add swales, infiltration trenches, and small farm dams where appropriate to hold and store excess water.

Out-the-ground impacts:

• Increased infiltration and deeper soil moisture profiles.
• Reduced surface runoff and soil loss.
• More stable root zones and improved drought resilience.

Swales, ponds and infiltration features: store where it falls

Swales (shallow, vegetated channels dug on contour) and connected infiltration basins slow runoff, allowing water to soak in rather than rush away. Ponds and small dams capture seasonal flows for later use, and properly located infiltration trenches or rock bunds help recharge subsoil moisture.

Practical steps

• Place swales on contour where runoff gathers, with vegetative cover to stabilise banks.
• Size ponds to match catchment area and expected inflow; include spillways and sediment traps.
• Use native grasses and deep-rooted plants in and around structures to increase infiltration and habitat benefits.

What to expect

• More capture of stormwater into profiles rather than quick runoff.
• Stored water for slow release to crops and the landscape.
• Reduced peak flows and downstream erosion.#

Biodiversity, corridors and non-chemical management

Landscape design that holds water also benefits ecological function. Hedgerows, polyculture strips, wetlands and refugia interrupt surface flows, filter sediments, and create microclimates that retain moisture. Avoiding blanket herbicide use and restoring native plant corridors increases soil life, which in turn improves infiltration and water-holding capacity. They also create habitat for pollinators, whose role in maintaining plant diversity strengthens vegetation cover and root systems, improving soil structure and ecosystem resilience.

How to get started

• Map existing habitat patches, riparian zones and movement corridors.
• Design hedgerows and shelterbelts to reduce wind and shade sensitive areas.
• Prioritise native species and staggered flowering to support pollinators and predators of crop pests.
• Replace blanket herbicide approaches with targeted mechanical and ecological methods.

On-the-ground impacts:

• Improved water filtration and infiltration.
• Increased natural pest control and pollination services.
• Stronger, more resilient on-farm ecosystems.

Integrating earthworks with irrigation and farm operations

Landscape earthworks change how and when water is available; that will alter irrigation timing and volumes. Work at this scale needs coordination: topographic design, soil-building practices, plant choices and irrigation systems should be planned together. Landscape water-holding measures are practical adaptation tools. They reduce the immediate impacts of heavy storms by slowing and storing flows, and they extend plant-available moisture during dry periods.  Data-driven design land reduces risk, stabilises yields and lowers reliance on costly supplemental water during droughts.

RRG NBS data-driven approach to support farmers and agribusiness:

• Survey & design: topographic mapping, hydrological modelling and on-farm design to locate keylines, swales and ponds.
• Implementation support: contractor coordination, earthwork supervision, planting plans and technical advice.
• Monitoring & verification: sensor networks, soil moisture monitoring and simple hydrological indicators to show changed infiltration and water storage.
• Capacity & finance: farmer training, co-design with communities, and assistance aligning projects to financing or incentive mechanisms where available.

This blended approach (ecological design plus data and implementation support) is how RRG NBS brings scalable, verifiable landscape solutions to farms and catchments.

Thoughtful earthworks and biodiversity-led design close the gap between rainfall and usable water. In Part 3, “Smart Irrigation Meets Regeneration,” we’ll bring these landscape changes together with sensors, crop coefficients and irrigation strategy, showing how data and biology create a low-input, resilient water system.