The Center for Water Resources for Agriculture and Mining (CRHIAM) is leading research on rainwater harvesting systems in Chile, exploring their potential to address the water crisis.
By: Belén Bascur Ruiz, Head of Communications CRHIAM mariabbascur@udec.cl
Images: Courtesy of CRHIAM and Pixabay
Water scarcity has intensified the search for innovative solutions to ensure access to water resources. This crisis underlines the urgency of finding sustainable alternatives that guarantee sufficient water for human consumption, the protection of ecosystems, and productive activities. Among these solutions, rainwater harvesting systems (SCALL, in Spanish) are emerging as a promising technology.
The Center for Water Resources for Agriculture and Mining (CRHIAM) has conducted research on the potential of SCALLS in Chile, examining the opportunities and challenges presented by their implementation in the country. The results have shown that these systems could contribute significantly to addressing the water crisis. However, regulatory and institutional barriers still hinder their development, in addition to uncertainties about the quality of the water obtained through this technology.
“SCALLs represent an opportunity to diversify the water matrix during drought periods. However, in Chile, we lack a robust institutional framework to manage this new water source” explains Dr. Gladys Vidal, Director of CRHIAM. “Although these systems allow water to be stored, we still have little information about the quality of the harvested water. One of our goals is to standardize the technology and study how air pollution and the collection surface affect water quality,” she adds.
Water quality
This technology is based on collecting, storing, and using rainfall, which can be used for non-drinkable purposes. It is also important to note that this water source can be used for subsistence agriculture. In regions from the center to the south of the country, where rainfall is more seasonal, implementing this method could represent an efficient solution to the water crisis.
However, the quality of the captured water needs a regulatory framework that ensures its healthiness for different uses. In fact, the work led by CRHIAM shows that harvesting rainwater on certain surfaces, such as zinc polycarbonate sheets and clay roof tiles, yields mixed-quality results. “The conductivity of the collected water is high in these materials, and its microbiological quality is acceptable, with fecal coliforms levels lower than those allowed for agricultural irrigation (less than 1 NMP/100 mL),” explains Dr. Gladys Vidal, director of CRHIAM.
The water quality regulations in Chile are based on two technical standards: NCh 409/1.Of2005 and NCh1333.Of1978. These establish the physical, chemical, and bacteriological requirements and the quality according to water use. However, no specific regulation allows for the safe management of rainwater harvesting.
SCALLs can reduce runoff and prevent flooding during heavy rains in urban areas with impervious surfaces. Internationally, these systems are regulated in arid and semi-arid regions around the planet, with facilities that consider this water source for daily life. In rural areas, these systems relieve pressure on water resources and optimize the use of available water.
In this context, CRHIAM has prepared several documents to contribute to the discussion on using SCALLs. Among these is the policy brief “Rainwater harvesting: encouraging the diversification of the water matrix,” which provides recommendations on the development of these systems in Chile to incorporate them into national regulations, as well as the CRHIAM communicational series ”Comparative study of rainwater harvesting regulation,” which reviews the legislation of the USA, Brazil, and Australia, to compare it with national regulations; and the ”Rainwater harvesting” manual, which explains the operation of these systems.
Last modified: 3 de septiembre de 2025
