Evaporation Suppression Research Articles

Estimating the cost-effectiveness of several reservoir evaporation suppression strategies: a case study

Reservoirs often experience significant evaporation, causing a reduction in productive water use and prompting calls to curtail the loss. While efforts to reduce evaporation have predominantly focused on improving efficiencies, there has been a comparatively limited exploration of the associated costs per unit of additional water yield. To address this, a unit reference value (URV) calculation approach was employed in a case study to compare the unit costs of this additional yield through various evaporation suppression methods. The evaluated techniques included chemical monolayers, shade cloth, and both hard and soft floating covers. The URV calculation factored in capital, operating, and maintenance costs over a 20-year term, specified water-saving efficiencies for each technology, and various environmentally driven evaporation and social discount rates. The resulting URVs were compared with those for raising the Clanwilliam Dam, a large-scale groundwater scheme and the URVs for desalination. Notably, monolayers emerged with the lowest URV, but their yield efficiency is severely compromised by their short lifespan and high susceptibility to wind. The URVs of shade cloth proved competitive with those of desalination but are practical only for relatively small areas. In contrast, floating hard and soft covers demonstrated higher per-unit water delivery costs than desalination due to more frequent capital equipment replacements caused by their faster wear and weathering. The findings suggest that current evaporation suppression technologies may be economically unfeasible for agricultural and even domestic water supplies. The URV calculation serves as a valuable tool for comparing the cost-effectiveness of diverse yield-additive strategies.

Droplet–droplet vapor-mediated interactions in confined environments

The evaporation of multiple droplets ensues ubiquitously in nature and industry. Vapor mediation caused by evaporating neighboring droplets is a demonstrated phenomenon that shows that droplets can interact with each other via the vapor in both open and confined configurations, i.e., the “shielding effect.” However, interactions between paired droplets in confined environments, more common in industrial processes, remain unexplored. In this Letter, we experimentally investigate the evaporation of water based paired sessile droplets on hydrophilic glass slides at different spacings in the absence and presence of an enclosed chamber. The results demonstrate that a confined environment significantly attenuates droplet evaporation, which intensifies with decreasing spacing between droplets. A 30%–82% increase in the droplet lifetime is found for the shortest distance studied in a confined environment, while results in an open environment are provided as a control. Both the local shielding effect and the global vapor accumulation due to confinement collaboratively induce such strong evaporation suppression. In addition, two well differentiated evaporation regimes ensue in a confined environment where the shielding effect initially dominates the evaporation suppression, whereas confinement governs the later evaporation stage. The later stage accounts for over 60% of the droplet lifetime. Such transition and further evaporation suppression, when compared to the classical shielding effect, highlights the importance of a confined environment in multiple droplet evaporation.

Long‐Term Performance on Drought Mitigation of Soil Slope Through Bio‐Approach of MICP: Evidence and Insight from Both Field and Laboratory Tests

AbstractDrought is a serious global environmental issue that causes water resource scarcity and threatens agriculture and food supplements. This study aims to investigate the long‐term performance of an eco‐friendly technique‐microbial induced carbonate precipitation (MICP) on drought mitigation at field and laboratory scales. Seven in‐situ slopes treated with different MICP rounds and cementation solution concentrations were subjected to 16‐month weathering. Tests were conducted to evaluate the evaporation characteristics, water retention capacity, and CaCO3 distribution. Laboratory soil samples were further prepared to provide evidence related to underlying weathering mechanisms. The results show that MICP has a time‐dependent performance on drought mitigation. After MICP treatment, soil performs a remarkable evaporation suppression ability and the evaporation rate can decrease by 50%. This is attributed to the soluble salts which increase soil water retention capability and dense hard crust which inhibits water vapor migration into the atmosphere. However, the soluble salts and crust are sensitive to weathering thus leading to degradation of MICP. Suffering 16‐month weathering, the MICP‐induced CaCO3 decreases by more than 60%. The evaporation rate of soil increases with MICP rounds and cementation solution concentrations and can reach nearly two times of untreated soil. MICP‐treated field soil exhibits weaker water retention capacity than untreated soil because MICP alters soil microstructure which expands macropores and decreases volume of micropores. Connected macropores act as favorable evaporation channels and accelerate evaporation. To ensure MICP long‐term effects, periodical treatments are necessary. The most effective MICP treatment scheme is four to six treatment rounds and 1.0 M cementation solution.

Shading solutions for sustainable water management: impact of colors and intensities on evaporation and water quality

This study investigated the effectiveness of suspended shade covers in reducing evaporation rates and improving evaporation suppression efficiency. The experiment tested different shading colors (black, white, and green) and intensities (50, 70, and 90%) while considering ecological and economical aspects. Evaporation was determined using class-A evaporation pans, and various microclimatic variables were measured below the shade covers. Additionally, water quality parameters such as EC, phosphate, nitrate, and chloride concentrations were monitored. The results showed that black covers had the highest evaporation suppression efficiency with values of 56.8, 53.6, and 51.7% observed under 90% shading intensity for the black, green, and white covers, respectively. Despite variations in water quality parameters which all met Jordanian and FAO standards for irrigation water, the economic feasibility of installing these covers was found to be viable due to the resulting benefits in water conservation and crop production. However, selecting the best shading cover should consider the multipurpose use of agricultural reservoirs, including aquaculture, and further studies are recommended to investigate other overlapping aspects on a reservoir scale.

Arid AREAS Water-Piled Photovoltaic Prevents Evaporation Effects Research

(1) Background: In arid and semi-arid reservoirs, water surface evaporation is the main method of water dissipation in order to inhibit the evaporation of water and enhance economic efficiency. The evaporation inhibition rate of water-piled PV at different times of the year is derived from the anti-evaporation test of water-piled PV, and a new idea is proposed for water conservation in plains reservoirs in arid areas. (2) Methods: The test was conducted by dividing the area into groups A and B, with and without PV panel shading. In situ observation and numerical calculation were used to measure the atmosphere’s temperatures, test group, and PV module. The saturated water vapor pressure difference was then calculated according to Dalton’s principle to analyze the economic benefits of water saving. (3) Results: Based on the test results, it was found that the shading of PV panels had a cooling effect on the water body, the PV module, and the atmosphere. Group A showed a 44.2% decrease in the saturation water vapor pressure difference compared to Group B. The maximum evaporation suppression rate of 40.2% was observed in July, while the minimum rate of 12.2% was observed in January. The average evaporation suppression rate for the entire year was 29.2%. By utilizing the annual water savings for agricultural irrigation, it is possible to cover 38 hm2 of land and generate a revenue of 39,000 CNY. (4) Conclusions: The photovoltaic water cover can effectively reduce water evaporation and generate economic benefits.

Analysis of Evaporation of Droplet Pairs by a Quasi-Steady-State Diffusion Model Coupled with the Evaporative Cooling Effect.

Multidroplet evaporation is a common phase-change phenomenon not only in nature but also in many industrial applications, including inkjet printing and spray cooling. The evaporation behavior of these droplets is strongly affected by the distance between neighboring droplets, and in particular, evaporation suppression occurs as the distance decreases. However, further quantitative information, such as the temperature and local evaporation flux, is limited because the analytical models of multidroplet evaporation only treat vapor diffusion, and the effect of the latent heat transfer through the liquid-vapor phase change is ignored. Here, we perform a numerical analysis of evaporating droplet pairs that linked vapor diffusion from the droplet surface and evaporative cooling. Heat transfer through the liquid and gas phases is also considered because the saturation pressure depends on the temperature. The results show an increase in the vapor concentration in the region between the two droplets. Consequently, the local evaporation flux in the proximate region significantly decreases with decreasing separation distance. This means that the latent heat transfer through the phase change is diminished, and an asymmetrical temperature distribution occurs in the liquid and gas phases. These numerical results provide quantitative information about the temperature and local evaporation flux of evaporating droplet pairs, and they will guide further investigation of multiple droplet evaporation.

Soil management considerations for water resiliency in a changing climate

AbstractProviding adequate water for crops is a key consideration for agricultural resiliency. Climate change is expected to exert substantial pressure on crop water supplies through increased rainfall variability and increased evaporative demand. The temporal and spatial variability of these climate change impacts, in combination with many feedbacks, at times operating at different scales, makes identifying specific, yet broadly applicable “one‐size‐fits‐all” soil management solutions challenging. Adaptations that work well in one location may represent a poor management choice in another. Considering the local combinations of climate, soils, and crop production systems is fundamental for identifying appropriate strategies. Nonetheless, some broadly applicable soil management pathways for increasing soil water availability can be identified: (i) maximizing rainfall capture, (ii) maximizing soil water storage capacity (intensity × volume), and (iii) suppressing unproductive evaporative water losses, particularly during intervals when leaf area of the primary crop is low. Selecting climate, soil, and production‐system‐appropriate tillage and surface cover management practices is among the most relevant considerations for improving soil water availability. Maintaining surface cover favors evaporation suppression and increased capture of precipitation. Tillage choices affect internal soil water storage through impacts on soil properties that influence storage intensity and by altering the volume of soil available for root growth, as well as through effects on surface cover. Promoted management practices aimed at improving soil water availability for increased agricultural resiliency must be practically feasible and cost‐effective in order to support their broad adoption, and such constraints should be an important consideration in their development.

Study on the Evaporation Suppression Efficiency and Optimal Diameter of Plain Reservoirs Covered by EPS Floating Balls in Arid Areas

Current research on the evaporation inhibition effect of polyethylene (PE) floats has been relatively comprehensive, and the cost is relatively high when it is arranged in remote mountainous areas. In order to find a more economical anti-evaporation material, five kinds of solid expanded polystyrene (EPS) floating balls with different diameters of 10 mm, 40 mm, 80 mm, 120 mm and 150 mm were selected to study the evaporation suppression efficiency (ESE) of EPS floating balls on the evaporation of reservoir water surfaces in arid areas. The outdoor evaporator test and the wind wave test in the reservoir area were carried out. Combined with various meteorological data, the evaporation inhibition rates of EPS floating balls with different diameters during a non-freezing period were calculated. The durability, seepage prevention, wind resistance, frost resistance, aging resistance and other properties of EPS were observed under different climatic conditions. In the evaporator test, the relationship between the diameter of the floating balls and the ESE was not a single function. The ESE of floating balls with a diameter of 40 mm was the highest, at 76.31%. In the wind wave test in the reservoir area, the ESE of the 10 mm floating balls was the lowest, at 34.79%, and the ESEs of the other four diameters of EPS floating balls were above 85% and positively related to the diameter of the floating balls. The test further improved the selection scheme for the diameter of the anti-evaporation floating balls, provided a reference for the practical application of EPS floating balls in future water-saving projects in the reservoir area, and enriched the content of water-saving projects for plain reservoirs in arid areas.

Efficiency of monolayers in evaporation suppression from water surface considering meteorological parameters.

The evaporation from water reservoirs has become a global issue due to climate change, limited water resources, and population growth. In this research, three emulsions of octadecanol/Brij-35 (4:1), hexadecanol/Brij-35 (4:1), and a combination of the alcohols with Brij-35, octadecanol/hexadecanol/Brij-35 (2:2:1), were used in water. One-way ANOVA was applied to compare the mean of evaporation in different chemical and physical methods, and factorial ANOVA was used to investigate the main and interactional effects of different meteorological parameters on the rate of evaporation. Results showed that two physical methods of the canopy and shade balls performed better than the chemical methods, with reductions of 60 and 56% in evaporation, respectively. Among the chemical methods, the octadecanol/Brij-35 emulsion had a better performance with 36% of reduction in evaporation. One-way ANOVA results showed that among the chemical methods, only the octadecanol/Brij-35 had no significant difference with shade balls with a 99% probability level (P < 0.01). On the other hand, factorial ANOVA showed that the temperature and relative humidity had the highest effect on evaporation. Octadecanol/Brij-35 monolayer had a lower performance than two physical methods at low temperatures, but after increasing the temperature, its performance improved. This monolayer had a good performance at low wind speed compared to physical methods; however, with increasing wind speed, its performance was severely affected. For temperatures of over 37°C, the evaporation rate increased more than 50% when the wind speed had changed from 3.5m/s to more than 8.7m/s.

Mosaic Patterned Surfaces toward Generating Hardly-Volatile Capsular Droplet Arrays for High-Precision Droplet-Based Storage and Detection.

Precise detection involving droplets based on functional surfaces is promising for the parallelization and miniaturization of platforms and is significant in epidemic investigation, analyte recognition, environmental simulation, combinatorial chemistry, etc. However, a challenging and considerable task is obtaining mutually independent droplet arrays without cross-contamination and simultaneously avoiding droplet evaporation-caused quick reagent loss, inaccuracy, and failure. Herein, a strategy to generate mutually independent and hardly-volatile capsular droplet arrays using innovative mosaic patterned surfaces is developed. The evaporation suppression of the capsular droplet arrays is 1712 times higher than the naked droplet. The high evaporation suppression of the capsular droplet arrays on the surfaces is attributed to synergistic blocking of the upper oil and bottom mosaic gasproof layer. The scale-up of the capsular droplet arrays, the flexibility in shape, size, component (including aqueous, colloidal, acid, and alkali solutions), liquid volume, and the high-precision hazardous substance testing proves the concept's high compatibility and practicability. The mutually independent capsular droplet arrays with amazingly high evaporation suppression are essential for the new generation of high-performance open-surface microfluidic chips used in COVID-19 diagnosis and investigation, primary screening, in vitro enzyme reactions, environmental monitoring, nanomaterial synthesis, etc.

Experimentation of Evaporation Suppression by Various Plastic Bottles Coverage Area

Evaporation significantly affects the loss of water in reservoir. The effective use of water-surface covering materials for evaporation reduction purpose is commercially performed including plastic spherical and circular shapes. This study initiates to reuse very common polyethylene terephthalate (PET) drinking-water bottles to cover water surface instead. The bottle shape could have a covering percentage ratio as much as 91% equal to a commercial ball or circular disk. The experiment was designed and conducted to prove the reduction of water evaporation rate using five simulated ponds. The testing aspect is the percentage of the coverage area over the water surface. Based on environmental impact concern, the deterioration of PET bottles due to hydrolysis reaction and ultraviolet rays in natural conditions is also investigated. The initial result from the experiment shows that PET bottles have a potential for the evaporation reduction which are a very cost-effective alternative to the existing commercial materials and help support the reuse of plastic waste.

Effects of floating covers used for evaporation suppression on reservoir physical, chemical and biological water quality parameters

AbstractIncreasing demand for freshwater in arid regions with chronic water shortage calls for expansion of water storage for drought periods while protecting storage from evaporative losses. A cost‐effective and scalable method for evaporation suppression uses floating elements; however, little is known regarding biochemical and water quality effects under these covers. Two identical reservoirs with area of 25 m2 and depth of 2 m were used to investigate the influence of floating covers on water quality parameters for a period of one year (2019–2020). One of the reservoirs was covered with Styrofoam discs, and results were compared with the uncovered one. Results showed that the evaporation suppression efficiency of floating discs gradually decreased from 80% in spring to about 60% in winter. The comparison between reservoirs revealed that the presence of floating covers decreased pH, electrical conductivity (EC), total dissolved solids (TDS) and dissolved oxygen by 11%, 11%, 15% and 36%, respectively. We observed an increase in nitrate (30%), phosphate (27%) and ammonia (95%) concentrations in the covered reservoir. Results also demonstrated more concentration of biological populations such as algae and protozoa in the uncovered reservoir. The findings highlight improvement of certain water quality parameters in covered reservoirs such as EC and TDS with potential impacts on irrigation systems and soil health and salinity constraints.

Chemically cross-linked gel storage for fuel to realize evaporation suppression

High-energy density liquid fuels are commonly used to operate combustors such as rockets, gas turbines, automotive engines, and boilers to make an energy transformation. To prevent a serious incident such as an explosion or a fire disaster, we have recognized practical issues of the liquid fuels that are safety and stability during transportation and storage, evaporation rate, and burning rate constant. In this experiment, ethanol is used as a liquid fuel and is retained on chemically cross-linked poly(N-isopropylacrylamide) (PNIPPAm) gel to use it as a polymeric gel storage for liquid fuels. In general, because the cross-linking structure of chemical gels is formed by covalent bonding, it is more stable than physical gels for a thermodynamic change such as temperature. The evaporation rate of the polymeric gel storage to suppress evaporating the ethanol is investigated. We finally demonstrate to obtain burning rate constants based on a changing mass of the polymeric gel storage during combustion. By demonstrating the polymeric gel storage combustion, we revealed existence of the d2 law in a droplet combustion.

Production of evaporation suppression floating covers using ultra-lightweight alkali-activated slag concrete

Evaporative losses from reservoirs exacerbate water shortage during dry spells. Notwithstanding the extensive application of self-assembling floating covers for suppressing evaporation, the cover material is often overlooked and limited to available choices such as plastics. The present study is aimed at the production of floating covers using ultra-lightweight alkali-activated slag concrete that offers a range of mechanical and chemical features. Concrete specimens were made with different percentages of ground granulated blast-furnace slag as the binder, sodium metasilicate as the alkaline activator and lightweight perlite aggregates with a density of 100–150 kg/m3. To solve the problem of fracture in the preliminary specimens, slag was partially replaced with 15, 20 and 30% lime. In addition, microsilica (10, 12 and 15%) was introduced to improve the mechanical properties of the samples. In designs without microsilica, 30% replacement of slag with lime resulted in the desirable density, strength and permeability of samples. Results showed that microsilica generally increased the density, resistance and thermal conductivity of samples by 7, 74 and 14%, respectively, while water absorption and permeability decreased by 15% and 14%, respectively. The dry density of samples was obtained between 340 and 516 kg/m3 with a compressive strength of 0.2–0.9 MPa and a conductive heat transfer coefficient of 0.067–0.093 W/mK.

Efficiency of Monolayers in Evaporation Suppression from Water Surface Considering Meteorological Parameters

Efficiency of Monolayers in Evaporation Suppression from Water Surface Considering Meteorological Parameters

Simulation of the Hygrothermal Behavior of a Building Envelope Based on Phase Change Materials and a Bio-Based Concrete

Phase Change Materials (PCMs) have high thermal inertia, and hemp concrete (HC), a bio-based concrete, has strong hygroscopic behavior. In previous studies, PCM has been extensively combined with many materials, however, most of these studies focused on thermal properties while neglecting hygroscopic aspects. In this study, the two materials have been combined into a building envelope and the related hygrothermal properties have been studied. In particular, numerical studies have been performed to investigate the temperature and relative humidity behavior inside the HC, and the effect of adding PCM on the hygrothermal behavior of the HC. The results show that there is a high coupling between temperature and relative humidity inside the HC, since the relative humidity changes on the second and third days are different, with values of 8% and 4%, respectively. Also, the variation of relative humidity with temperature indicates the dominant influence of temperature on relative humidity variation. With the presence of PCM, the temperature variation inside the HC is damped due to the high thermal inertia of the PCM, which also leads to suppression of moisture evaporation and thus damping of relative humidity variation. On the second and third days, the temperature changes at the central position are reduced by 4.6% and 5.1%, compared to the quarter position. For the relative humidity change, the reductions are 5.3% and 5.4% on the second and third days, respectively. Therefore, PCM, with high thermal inertia, acts as a temperature damper and has the potential to increase the moisture buffering capacity inside the HC. This makes it possible for such a combined envelope to have both thermal and hygric inertia.

Potential Drought Mitigation Through Microbial Induced Calcite Precipitation‐MICP

AbstractExtreme drought events occur more frequently due to climate change. Soil water loss through evaporation is therefore significantly intensified. This study introduces an environment‐friendly and sustainable bio‐mediated technique, known as microbially induced calcite precipitation (MICP), for water evaporation suppression in clayey soils. Through lab‐scale evaporation tests, we investigate the effects of cementation solution concentration (0.5, 1.0, and 1.5 mol/L) and MICP treatment procedure (one‐phase and two‐phase MICP methods) on both macroscale (e.g., water loss, desiccation cracking) and microscale (e.g., microstructure variations) behaviors of soils. Experimental results show that MICP is capable of improving water retention capacity and enhancing the inter‐particle bonding of clayey soils. Both water evaporation rate and total water loss decrease with the increasing concentration of cementation solution and the number of MICP treatment cycle. For most testing samples, both one‐phase and two‐phase MICP treatment methods have a similar influence on soil properties. Further microstructure characterizations reveal four key factors contributing to the improved soil response under drying, including dense surface crust, remediated desiccation cracks, smaller pore size and residual solutes. Dense structure of surface crust suppresses the migration of water vapor into the atmosphere. Calcite crystals tend to reduce the evaporation surface if precipitated within cracks, and clog the movement of pore water if precipitated within the soil pore space. This study is expected to improve the fundamental understanding of soil‐atmosphere interactions under MICP treatment and provide insights into the potential application of bio‐mediated technologies as a nature‐based solution for drought mitigation in arid and semi‐arid region.

Cultivation of non-irrigated spring wheat in temperate free-grazing steppe improved both ecosystem and canopy water use efficiency

The temperate steppe in northern China is important for sandstorm control and food/livestock production. Understanding the influence and regulatory control of cultivation on the water balance and water use efficiency (WUE) of this water-limited region would promote the sustainability of local ecosystem and food supply. This study combined eddy covariance system observational data and the Shuttleworth–Wallace model to investigate evapotranspiration (ET) and its composition in paired sites, including a free-grazing steppe site and an adjacent site reclaimed for spring wheat cultivation in Xilinhot, Inner Mongolia. Further, analysis of the WUE of both the ecosystem (WUEE) and the canopy (WUEC) under the two sites showed that the mean daily gross primary productivity (GPP) of the cultivation site was 3.84 gC·m−2·d−1, i.e., 15.7% higher than that of the free-grazing site (3.32 gC·m−2·d−1). Compared with the free-grazing site (1.76 kgH2O·m−2·d−1), the mean daily ET of the cultivation site (1.40 kgH2O·m−2·d−1) was reduced by 20.7%. The difference in ET was due mainly to suppression of evaporation at the cultivation site from increased shading associated with a higher leaf area index (LAI). The largely increased GPP of the cultivation site fundamentally contributed to the 54.7% higher WUEC (4.75 gC·kg−1H2O) in comparison with the free-grazing site (3.08 gC·kg−1H2O). The WUEE of the cultivation site was 57.9% higher than that of the free-grazing site. The variation of transpiration of the free-grazing site explained 64% of the change of WUEC. These results indicate that land use differences in the temperate steppe area changed vegetation productivity substantially. Moreover, ecosystem ET and its composition, as well as large-scale land use change, might influence the regional water use pattern and mass balance. Our findings help clarify the impact of typical land use change on regional WUE, and could promote development of visionary and effective strategies for the use of the limited resources in arid–semiarid regions.

Effect of continuous and modular floating covers on evaporation losses and microalgal growth

Evaporative losses from the water surface are substantial. Continuous floating covers strikingly suppress evaporation, but adversely affect the water environment. However, modular floating “elements” covers might overcome this issue, but with less evaporation suppression efficiency. We hypothesized that modifying the continuous floating covers by decreasing the coverage fraction (CF) could merge the advantages of both types. Two experiments were conducted to evaluate and compare the influence of modular and continuous floating covers on evaporation losses with emphasizing their impacts on the water environment by determining microalga growth as a bio-indicator. The effect of three modular floating covers, i.e., partially water-filled plastic potable bottles (W-PB), air-filled plastic potable bottles (A-PB), and styrofoam (STF)-disks on the evaporation rate was evaluated. In the second experiment, we investigated the influence of white spheres on evaporation rate in comparison to three continuous floating covers, i.e., styrofoam sheet (STF-sheet), white plastic sheet (WPS), and black plastic sheet (BPS), using three CF, i.e., 0.9, 0.95 and 1.0. The results revealed that modular floating covers decreased evaporation rate for the two months by 53.3, 44.6, 43.0% for STF-disks, W-PB, and A-PB, respectively. In the second experiment, the lowest evaporation rate was obtained using continuous floating covers at CF=1, in which all covers were acting equally, signifying the importance of CF over cover color. However, at CF=0.9, white spheres showed similar evaporation suppression efficiency to white continues floating covers, i.e., STF-sheet and WPS, but higher than the BPS, signifying the role of cover color over cover type when CF<1. Microalgae growth was positively affected by STF-disks and white spheres, and negatively by plastic potable bottles treatments. All continues floating covers at CF=1, inhibited microalgae growth, while at CF<1 continues floating covers boosted microalgae growth, except the BPS. In conclusion, the highest evaporation suppression (~95%) was obtained using continuous floating covers at CF=1, but with potential adverse impacts on the water environment. Modifying the continuous floating covers by decreasing the CF, increased water-saving, and enriched water ecology, relative to modular floating covers.

Reducing Evaporation From Water Reservoirs Using Floating Lattice Structures

AbstractTo accommodate the increase in irrigation water demand, millions of reservoirs were built during the last decades all over the world, but half of the stored water is lost to evaporation. Opaque floating elements are used to cover the reservoirs and suppress evaporation. However, they limit light transmission and oxygen exchange, thus preventing the coupling of fish farming with irrigation. The concept of open, lattice‐like, structures that suppress evaporation while allowing transfer of light and oxygen to the water is presented here. Experimental results under laboratory conditions show that the structure studied has reduced the wind speed above the free water surface, and has suppressed evaporation by 40%–60%. The performances of the lattice‐like structure were compared to those of floating balls. In the absence of wind, the balls that cover ∼90% of the water surface with opaque material are much more efficient in suppressing evaporation than the lattice structure that leaves ∼90% of the water surface uncovered. When the wind blows, the balls‐cover is still more efficient in suppressing evaporation than the lattice structure. However, the ratio between evaporation from the basin covered with the lattice structure and the one covered with balls is higher than 0.75. That shows that the performances of the investigated structure are equivalent to opaque elements covering 50%–85% of the surface. This emphasizes the high efficiency of the proposed concept to achieve significant evaporation suppression while ensuring transfer of light and oxygen, thus allowing efficient management of dual reservoirs.