Rainwater Supplies Agricultural Water to Fields…RDA’s Non-Powered Technology Reduces Water Shortages by Up to 57%

At the demonstration site in Hapcheon, South Gyeongsang Province, the average daily water shortage, which had reached 98.3㎥, was reduced to 41.3㎥. The period during which drought continued without interruption, that is, the maximum number of consecutive days of water shortage, also shortened from 18~21 days to 13~16 days. These figures came from the Hapcheon demonstration site, where there was no electricity, no groundwater well, and no water source to draw from. There was no power source pulling in the water. Rainwater, the elevation difference of the terrain, and the pressure that water creates on its own were all there was.

This is the story of the ‘non-powered integrated agricultural water supply technology’ whose development was led by Researcher Seok-cheol Yu of the Upland Agricultural Machinery Division at the National Institute of Agricultural Sciences under the Rural Development Administration. With this technology, Yu received the Minister’s Award on September 2 at the ‘Korea Disaster Safety R&D Awards’ hosted by the Ministry of the Interior and Safety. The ministry has presented the award every year since 2019 to recognize disaster safety R&D achievements by universities and research institutes nationwide, and this year 8 people were selected through institutional recommendations and presentation evaluations. 

“An award I received as the representative thanks to the joint research team”

Yu first credited the research team in his remarks on winning the award. He said, “It was not something I did alone; it was thanks to the joint research team,” adding, “Gyeongsang National University, Soonchunhyang University, and the National Institute of Agricultural Sciences carried out the project together, and thanks to the hard work of the researchers, I received the award on their behalf.” He continued, “I applied after being recommended by the National Institute of Agricultural Sciences, but I had doubts about whether I could win,” and added, “Because I had not expected it, I was even happier after the screening results were announced.”

The research that led to the award was a joint project conducted from 2023 to 2025, but the time devoted to rainwater research has been far longer. Yu has steadily continued research using rainwater since 2013. He explained the background, saying, “Until now, we had supplied storage containers for farms in plains to use, but in mid-mountain areas or highlands there were limitations because it was difficult to use wells and groundwater,” and “we began this research to develop technology that can be used without electricity.”

As climate change increases sudden droughts that develop rapidly over short periods, the risk of water shortages in upland crop cultivation areas is becoming constant. In particular, in mid-mountain and highland cultivation areas, it is difficult to develop wells and supply electricity, making it hard to apply existing methods for securing alternative water sources such as sewage reuse or groundwater wells. They are effectively blind spots in securing alternative agricultural water.

Collection-Pretreatment-Storage-Transfer, the 4 steps of making agricultural water without electricity

The technology developed is an integrated system in which the ‘collection-pretreatment-storage-transfer’ process circulates automatically in 4 stages without a power supply. Its core is to capture rainfall runoff that, when it rains, cannot soak into the ground and simply flows along the surface, keeping it as agricultural water instead of letting it run off.

Asked about how it works, Yu explained by following the path of the water. A small runoff stream refers to a small waterway through which water flows along mountain slopes when it rains. He said, “In mid-mountain areas, when it rains, we use the small runoff streams where water flows, connect piping to a collection device, and the water that passes through enters a 5-ton main water tank,” adding, “Large foreign substances are filtered out by the collection device, while smaller ones are removed by a hydrocyclone filter we developed ourselves.” He added, “When the main water tank is full, the overflowing water passes through the filter once more and moves on to the next water tank, and the system was designed to reach farm and village units.”

According to the research team, the separation efficiency of the hydrocyclone, which uses centrifugal force to separate soil and foreign substances, is up to 96%, and the maximum collection capacity of the collection device is 8.4㎥ per hour.

The method of sending stored water to fields depends on the terrain. Yu explained, “We transfer it by distinguishing between highlands and lowlands, letting water in lowlands flow naturally by gravity using the elevation difference, while water for highlands is lifted by a hydraulic ram pump.” A hydraulic ram pump is a device that pushes water up to higher places using the pressure generated when flowing water stops, and the maximum non-powered lift of the pump developed by the team is 12m. That is roughly the height of a 4-story building.

At this point, surpassing the limitations of commercial products is cited as a technical achievement. Yu said, “When we used a commercial hydraulic ram pump, there were problems with large losses, such as heavy water consumption and leakage,” adding, “We supplemented that part by developing the key component, a waste check valve, in-house and have completed the patent application.”

The research team has filed a total of 4 patents for this technology. ‘Monitoring and Control System for Upland Crop Irrigation’(10-2025-0182493), ‘Rainfall Runoff Collection and Water Treatment Device, and Rainfall Runoff Treatment Method Using the Same’(10-2025-0046790), ‘Non-Powered Upland Field Irrigation System’(10-2025-0117299), ‘Non-Powered Agricultural Water Supply System Using Rainfall Runoff’(10-2025-0166502) are the four. 

Jangsu and Hapcheon, separately verified in two places with different conditions

The research team conducted field demonstrations at 2 locations with different climate and topographic conditions, Jangsu County in Jeonbuk State and Hapcheon County in South Gyeongsang Province, from April 2023 to November 2025. There was a reason for choosing the two locations.

Yu said, “We judged that we should try it in places with different terrain and climate conditions,” explaining, “Jangsu is a mid-mountain area where runoff flows constantly even when it is not raining, while Hapcheon is an area where rainwater can be collected only when it rains.” He added, “We conducted demonstrations by dividing the sites into one where water always flows and one where rainwater gathers, and both were areas short of water.”

As a result of the demonstrations at the two sites, the average daily water shortage decreased by up to 57% . In Hapcheon County, the daily water shortage of 98.3㎥ was reduced to 41.3㎥. The maximum number of consecutive days of water shortage was shortened from 18~21 days to 13~16 days, and the integrated system produced a daily average of 27㎥ on its own, stably supplying irrigation water. 18 global climate models(GCM) and, among the Shared Socioeconomic Pathway(SSP) scenarios, future climate verification applying SSP2-4.5 and SSP5-8.5 also continuously confirmed the effect of reducing water shortages.

The quality of the stored water also met all agricultural water standards. Analysis of treated water at the demonstration site in Daegok-ri, Janggye-myeon, Jangsu County showed pH 7.87, EC 0.001dS/m, TOC 5.832㎎/L, SS 26.8㎎/L, T-N 0.9㎎/L, T-P 0.0㎎/L, with all 6 items within the standards. 

Yu explained that farmers’ reactions were also not bad. He said, “When we demonstrated it in Hapcheon last year, farmers responded favorably,” adding, “We were told that using this technology would make it possible to secure water even in mid-mountain areas and highlands.” 

A monitoring system that fought moisture in water tanks

The development process was not entirely smooth. The most difficult part, unexpectedly, was not the equipment for collecting and sending water, but the monitoring system that lets farms check how much water they can use.

Yu said, “We developed an app that allows farms to check how much water is in the water tank and how much they can use, but during the demonstration, the ultrasonic water level meter we used lost precision as moisture built up in the water tank,” adding, “That became a problem.”

The solution was to change the method of measuring the water level itself. Instead of a non-contact method, they chose a device that reads the water level through water pressure while submerged. Yu explained, “The water level measurement problem was resolved by switching from an ultrasonic water level meter to a pressure-type water level meter,” adding, “Through this, the app-based rainfall runoff monitoring system came to operate smoothly.”

Securing durability with field deployment in mind was also a task. Yu said, “As we applied and demonstrated it in the field, the durability of the collection device and hydrocyclone, among others, was key,” adding, “Because there were issues such as damage during dissemination or difficulty in maintenance, we focused our research on reducing maintenance costs compared with ordinary facilities so that maintenance and repair would be easy for farms and in the field.” 

Initial investment of 8.7 million won…cheaper than a well

In terms of economic feasibility, a key factor for expanding dissemination, it was also assessed as more advantageous than the groundwater well method. 5-ton water tanks, the initial investment for the non-powered integrated system including 5 units is 8.7 million won, which is 37.4% less than the 13.9 million won cost of a solar-powered groundwater well system. Annual operation and maintenance costs are also 750,000 won, which is 25% lower than the well method(1 million won). Operating costs consist of 500,000 won for water tank cleaning, 150,000 won for replacing consumables for pipes, valves, joints and the hydraulic ram pump, and 100,000 won for outsourcing water quality analysis.

Yu said, “When we conducted an economic feasibility assessment, the facility installation cost was in the 8 million won range, whereas installing a groundwater well costs around 14 million won,” adding, “We believe our technology is more economical than groundwater wells, and for that reason we expect dissemination to expand.” 

2027 project reflection target…also for livestock·landscaping·firefighting water

The technology is already moving into the policy stage. In December 2025, the research team made a policy proposal to the Ministry of Agriculture, Food and Rural Affairs, requesting that it be included among the eligible support targets of the ‘Water Development Project for Drought Preparedness’. Yu said, “It is currently being pursued, and we are trying to commercialize it with 2027 as the target,” adding, “Local governments have also contacted us saying they are curious about this kind of technology.” He continued, “When we spoke again with the agriculture ministry, they said it could be reflected if there is demand from local governments,” adding, “We believe it can be reflected if requests from local governments continue, and we are continuing to push for it.”

The plan is also to expand the fields of application. Yu said, “We believe it can be fully used not only in agriculture but also in livestock farming or landscaping, and we plan to expand it into non-agricultural fields.” He also mentioned its potential use for emergency water supply in disaster response, especially as firefighting water. He said, “Stored water can be used in urgent situations such as fires simply by connecting a hose, so I think that part is also fully possible.” Regarding overseas application, he also said, “I believe it can be sufficiently integrated.”

Because the structure allows water tanks to be increased in stages, the supply scale can also be expanded. Yu explained, “Since water tanks are installed in stages, it is enough water to sufficiently supply an ordinary rural village.”

The focus of follow-up research will shift from technology development to dissemination. Yu said, “We have been doing rainwater research for a long time, and I think we have secured technological advancement,” adding, “What matters is how much we expand and disseminate this technology.” He also noted that Rural Development Administration Administrator Seung-don Lee has emphasized technology dissemination. Yu said, “As the administrator also emphasizes dissemination, we intend to pursue follow-up research in the direction of demonstration studies for expanding dissemination and designation as new-technology agricultural machinery.” Expansion into a hybrid method linked with small-scale groundwater in preparation for extreme drought is also under consideration. 

From greenhouse disaster resistance to rainwater, and then to agricultural machinery safety

Yu joined the Disaster Prevention Engineering Division of the Agricultural Engineering Department at the National Institute of Agricultural Sciences through open recruitment in October 2013. A native of Jeonju, he majored in agricultural machinery and completed his bachelor’s and master’s degrees at Jeonbuk National University. He explained the reason for joining, saying, “I heard that the Rural Development Administration was relocating to Jeonju, and I also wanted to make use of my major.”

His research trajectory runs through disasters and safety in agricultural fields. 2016, he has conducted research on the safety of disaster-resistant facilities in greenhouses for horticulture and special crops at the Disaster Prevention Engineering Division, and as his research laboratory was incorporated into the Upland Agricultural Machinery Division last year, he shifted the focus to research centered on production infrastructure safety. Currently, he is also conducting research in the field of agricultural machinery safety. GPS This research analyzes the actual use of agricultural machinery using data, and at a pilot complex in Baeksan-myeon, Gimje City, Jeonbuk State, GPS terminals are attached to tractors, rice transplanters, and combines to analyze the level of work optimization. Yu explained, “In agricultural work contracting carried out by Baeksan Nonghyup, terminals are attached to combines and other machines, and we analyze the workload using GPS data.”

Asked what he wanted to say to farmers struggling with drought, Yu again brought up the field. He said, “Climate change is so severe that farming is becoming increasingly difficult,” adding, “In this situation, we will strive to create technologies useful in the field so that our research can ease farmers’ difficulties even a little.”