Villa park water research
Why does one mango tree produce abundant fruit, while another tree only a hundred meters away produces almost none?
This was the exact question that we faced during an agricultural consultancy project on a resort island in the Maldives last fall. That question became the starting point of a groundwater research project together with our partner Tewaii.
Understanding your water source is important for agriculture everywhere in the world, but for island-based agriculture it becomes even more critical. Small island environments are uniquely vulnerable. Most islands in the Maldives are small, often no larger than 1 km², and consist mainly of porous coral rock and sand. There are no rivers or freshwater lakes, yet freshwater still exists underground in the form of groundwater lenses. These freshwater lenses float on top of the surrounding seawater and are the hidden foundation of many island ecosystems.
Trees and vegetation tap into these freshwater reserves through their roots. On some islands, freshwater even reaches the surface and creates wetlands and lush vegetation zones. These ecosystems not only support biodiversity but also help stabilize the island itself by reducing erosion and protecting coastlines.
At the same time, these freshwater systems are fragile. Overextraction, salinization, pollution, or poor water management can damage or even collapse a groundwater lens. Once degraded, recovery can take years, while the impacts on agriculture, ecosystems, and island stability can be immediate.
To better understand the island’s water system, we conducted a practical groundwater assessment using field methods adapted to remote island conditions. With some makeshift tools, we drilled several shallow wells across different locations on the island and collected groundwater samples. Conducting research on remote islands often requires creativity and practical problem-solving with the tools available on-site.
Additional samples were collected from rainwater storage systems and RO (Reverse Osmosis) water sources used on the island. The samples were transported for laboratory analysis in the Netherlands, where the chemical composition of the water was analysed in detail with support from Tewaii.
The results revealed several interesting patterns. Overall, the groundwater quality was acceptable for potential agricultural use, with no major indications of chemical contamination or sewage pollution. The groundwater samples showed relatively low salinity levels and no significant sodicity risks, which is important for maintaining healthy soil structure, especially in sandy island soils.
At the same time, the research clearly showed how dynamic and variable island groundwater systems can be. Even within relatively short distances across the island, differences in groundwater composition and crop performance became visible. One groundwater sample showed noticeably higher salinity and mineral concentrations than nearby locations, while another area showed elevated nitrate concentrations that may indicate localized human influence.
The groundwater samples also showed relatively high pH values, which is typical for coral island environments where carbonate minerals naturally buffer the groundwater. This highlights why groundwater research is essential before developing agriculture or designing fertigation strategies on islands. Water that may appear suitable at first glance can still influence nutrient availability, fertilizer efficiency, or long-term soil conditions.
An important observation from the assessment was that the groundwater samples mainly represented the shallow upper layer of the freshwater lens. Because this upper layer is strongly influenced by recent rainfall recharge, salinity levels may temporarily appear lower due to dilution effects. This means that a single sampling round only provides part of the picture. Seasonal rainfall, groundwater abstraction, tidal influence, and long-term climate conditions can all influence groundwater quality over time.
For this reason, groundwater monitoring and sustainable yield assessments become essential before groundwater is structurally used for irrigation purposes.
The research also highlighted the importance of rainwater as a strategic agricultural resource. The rainwater sample showed exceptionally high quality and low salinity, making it highly suitable for greenhouse cultivation, hydroponics, and sensitive crops. In fact, the rainwater quality appeared more suitable for some high-tech agricultural applications than one of the RO water samples.
Interestingly, the assessment also showed that not all RO water is automatically “perfect” irrigation water. Differences between two RO samples suggested possible mixing with another water source or contamination after treatment. One sample showed elevated sodium and boron concentrations, which can become problematic for sensitive crops and recirculating hydroponic systems. These findings demonstrate the importance of monitoring not only groundwater, but also desalinated water systems.
Another important insight was related to irrigation efficiency. On many islands, landscaping and irrigation are still performed using garden hoses, resulting in significant evaporation losses. This type of water loss, which falls under the ‘non-beneficial consumption’ of irrigation water, increases both desalination costs and energy use. Improving irrigation efficiency can therefore significantly reduce operational costs while simultaneously protecting valuable freshwater resources.
Overall, the assessment demonstrated that water management is one of the most important foundations for successful agriculture on small islands. Groundwater research not only helps determine whether agriculture is feasible, but also helps optimize crop selection, fertigation strategies, irrigation efficiency, and long-term sustainability.
For island owners, growers, resorts, and funding organisations, understanding the island water system is often the first step toward developing resilient and productive agriculture systems.
Together, Tewaii and Resilient Island combine practical island agriculture expertise with water research and analysis to support sustainable agricultural development in island environments. From groundwater assessments and water quality analysis to fertigation strategies, greenhouse development, and long-term water management planning, we help islands better understand and utilize their most valuable resource: water.
Interested in understanding the agricultural potential and water resilience of your island? Feel free to contact Resilient Island or Tewaii to explore how groundwater research and sustainable water strategies can support your island development plans.
