Investing in floodwater as a renewable water resource in Saudi Arabia
Several regions in Saudi Arabia are currently experiencing heavy rainfall, leading to significant wadi flows and highlighting the importance of floodwater as a renewable water resource. Given the global climate change, questions arise regarding the effective utilization of this water and the accuracy of current estimates compared to the actual situation on the ground.
The historical roots of water harvesting methods in the Arabian Peninsula
Historically, the Arabian Peninsula has suffered from a scarcity of permanent surface water resources due to its desert nature and arid climate. This challenge has driven successive generations to devise traditional methods of rainwater harvesting and the construction of simple dams to conserve every drop of water. In the modern era, with urban development and population growth, the need to develop these ancient methods and transform them into comprehensive national strategies has intensified. In this context, Dr. Raed Al-Harbi, Associate Professor of Water Resources Engineering at King Saud University, emphasized that flash floods are not merely a transient seasonal phenomenon, but rather a renewable water resource of high developmental value if properly understood and managed. He pointed out that the primary challenge lies not in the existence of flash floods, but in the ability to measure them and transform them into accurate data usable for planning.
The role of floodwater in replenishing national water resources
Dr. Al-Harbi explained that rainfall is the primary source for replenishing renewable water resources in the Kingdom. Despite its fluctuations and concentration over short periods, it contributes to the formation of flash floods that flow through valleys and ravines. He added that these floodwaters contribute to supporting water resources through two main pathways: first, by replenishing renewable groundwater reservoirs through seepage into the ground, and second, by harvesting them through dams and rainwater storage facilities. He indicated that hydrological estimates suggest that the average annual volume of flash floods in the Kingdom is approximately 8 billion cubic meters, of which about 60% can be utilized. However, these figures remain general estimates and do not always reflect the detailed reality.
Bridging the gap between theoretical estimates and field measurements
The water expert pointed out a clear gap between estimation and measurement, explaining that current field observations of flash flood strength and width suggest large quantities of water. However, the lack of direct field measurements of water levels and flow velocities makes it difficult to convert these observations into accurate data. He emphasized that field measurement forms the scientific basis for building hydrological and hydraulic models, which are key tools for understanding flash flood behavior and accurately estimating their volumes. These models are also used to assess water harvesting opportunities and support urban planning strategies to mitigate risks.
Strategic dimensions and regional impact of water resources management
At the local and regional levels, optimal investment in the water sector has profound strategic dimensions. Locally, it contributes to achieving the goals of Saudi Vision 2030, which aims to achieve sustainable water and food security. Regionally, the Kingdom presents a leading model for countries facing similar climatic conditions in how to manage scarce resources. Dr. Al-Harbi pointed out that some floodwater is lost due to its flow towards coastal areas or open areas with high evaporation rates, making advance planning essential to transform it from a potential threat into a supportive resource. He emphasized that the state has given increasing attention to this issue within the National Water Strategy, which aims to reduce reliance on non-renewable groundwater.
Integrating national efforts towards an advanced early warning and measurement system
He also noted that the cloud seeding program is one of the initiatives supporting the enhancement of water resources, but any increase in rainfall necessitates a greater focus on developing measurement systems. He emphasized the importance of establishing a comprehensive national flood monitoring system based on field measurements, modeling, and early warning, while standardizing data and making it available to research institutions and universities. This integration will undoubtedly contribute to improving the efficiency of water planning and transforming floods from a seasonal challenge into a sustainable development opportunity that enhances quality of life and supports the national economy.
