Protecting water, sustaining agriculture Large volumes of water are lost through evaporation from irrigation ponds every year, and the problem is set to grow more severe in future as global temperatures rise. The team behind the H2OLock project are developing a new, modular-based solution to cover these ponds and reduce losses, as José Miguel Gimeno explains. The vast majority of agricultural irrigation ponds are left entirely uncovered, leaving them vulnerable to significant losses through evaporation when temperatures rise. With water scarcity a major concern across Europe, which is likely to intensify as our climate changes, it’s increasingly important to protect existing resources and use them efficiently. “We can’t allow ourselves to be wasteful with water,” stresses José Miguel Gimeno, an engineer at Arana Water Management, a company which specialises in managing and saving water. As part of his work on the EU-backed H2OLock project, Gimeno is developing a solution designed to reduce losses through evaporation, which he believes could play an important role in protecting the security of water supplies, which is a major issue in the context of climate change. “This solution is designed to address concerns around water scarcity, which are likely to grow more prominent in future with the increasing likelihood of droughts,” he says.
modules and blankets, and functions by preventing the sun’s rays from reaching the water surface, so reducing losses from evaporation. This idea dates all the way back to classical antiquity, when the Romans covered ponds, now Gimeno The floating cover is compatible with the function of a wildlife watering station, however, it scares away large flocks of birds.
H2O Lock project The solution itself is comprised of a low-weight set of sectorized floating
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and his colleagues have developed a sophisticated solution called evapo-control to cover challenging surfaces. “Our system has been developed for surfaces that have historically been very difficult to cover,” he explains. High winds are a particular problem in terms of covering ponds, an issue which the project team is working to address. “We are working to cover ponds of up to 10 hectares in size, and such a big surface is by nature more exposed to the wind and the elements,” continues Gimeno. “The main advantage of evapo-control is that its geometry combats the wind more effectively than existing solutions.” This system is designed for man-made ponds that are not renatured or connected to other sensitive aquatic ecosystems, with the aim of protecting and conserving the stored resource. A lot of effort and energy has been expended in preparing this water for animal consumption or to support the growth of plants and crops, heightening the importance of protecting it. “The water stored in irrigation ponds has been extracted, treated, transported or regenerated from other processes, so there
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A test pond measuring over one hectare in Portugal. The floating modules automatically organize themselves, covering 100% of the pond’s surface thanks to its hexagonal shape and the action of the wind.
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Floating solar installation assembly diagram tailored to the needs of each farmer.
are a lot of environmental and economic costs associated with it. The water is ready to be used at this point, it’s the last link in the chain,” stresses Gimeno. While some farmers may in the past have been relatively careless about water management, Gimeno says profligacy cannot be justified in the current circumstances. “In the near future all water storage sites must be covered in order to protect resources effectively,” he stresses. The project’s research holds great importance for the agricultural sector, which depends on a reliable supply of water to irrigate fields, which is under threat from current high levels of evaporation. The solution has been tested on a 3-hectare pond in Spain and on another one of more than one hectare in Portugal. “Our tests have shown that we are able to reduce losses through evaporation by more than 80 percent,” he outlines. This represents a substantial saving, which if translated more widely would alleviate water scarcity concerns, while Gimeno says covering water also has other positive effects. “By covering water you also protect it from other problems, such as algal growth. When you cover a water surface, you prevent light from reaching algae, so it can’t photosynthesise and ultimately it dies,” he explains. “It also prevents other problems, such as deposits of bird faeces, which lead to microbiological contamination.” A pond has to be completely covered to prevent algal growth, as even a very small input of light is enough to support growth, which then affects water quality. Properly protecting water eliminates the need to use
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chemical algaecides and improves its quality, facilitating its management. “All irrigation systems have a filter. If we can prevent algae growth, then that means less material will get stuck in filters, and they won’t need to be used as regularly,” outlines Gimeno. This means farmers will have to spend less time and money on maintenance, reducing costs, while the system can also generate renewable energy, bringing further financial
project team are working to heighten awareness of the solution in agriculture, and help move the sector to a more sustainable footing. One of the partners involved in the project is the Community of Irrigators of Lorca, a large association of farmers in the southeast of Spain who manage water jointly. “We are doing demonstration sessions showing the technology to groups of their farmers who could decide to install
“The solution is designed to address concerns around water scarcity, which are likely to grow more prominent in future with the increasing likelihood of droughts.” benefits. “The evapo-control solution also incorporates photovoltaic panels on floating blankets to generate energy,” says Gimeno. “The solution has been shown to work very effectively in this respect, producing the same amount of energy as a conventional ground installation of solar panels.” This provides a powerful incentive to farmers to adopt evapo-control, and the
it in their own ponds,” explains Gimeno. The assessment tests, which lasted almost two years and were conducted by the Polytechnic University of Cartagena, one of the partners in the H 2OLock project, are coming to an end, with results showing a reduction in evaporation losses of more than 80%. The team is now focusing on communication and demonstrating its
Floating solar plants can be installed on ponds with or without the rest of the surface protected with Evapo-control.
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