Water Security Risk – Part Six
Amirhossein Khodaei – Researcher
Practical, Localized, and Generalizable Solutions at the National Level (Part Two)
The Secrets of Water Management Over Time: From Complex Challenges to New Horizons
Water is a vital source of life and the foundation of sustainable development for every country. However, its management has always faced numerous challenges. Over the past decades, water-management policymaking in our country has followed a complex and winding path, influenced by climatic, economic, social, and technological factors. Examining this trajectory not only reveals the problems and weaknesses of the past, but also presents promising prospects and unique opportunities for improvement and innovation in water-resource management. In this analysis, we will take an in-depth look at the influential factors and the key role of managers in shaping water policies, while presenting ways to move toward a sustainable and hopeful future.
The Impact of Dredging on Water Conservation
The Impact of Failing to Dredge Rivers and Dams on Water Loss in Iran
Failure to dredge rivers and dams causes sediment to accumulate in their beds and reduces the effective storage capacity of reservoirs. As a result, during heavy rainfall, part of the water flows over the spillways instead of being stored in dams and is consequently lost. Studies indicate that in Iran, due to sedimentation resulting from insufficient dredging, approximately 0.5% to 0.75% of the effective storage capacity of dams is lost annually. This figure becomes highly significant over the long term. For example, the capacity of the Dez Dam has reportedly declined by nearly 20% over approximately 40 years of operation, rendering a portion of its capacity unusable. In addition, estimates by the World Bank indicate that approximately 236 million cubic meters of the country’s water-storage capacity are lost annually during the rainy season as excess water overflows from reservoirs for this reason.
This reduction in capacity causes dams to fill more quickly during the rainy season, resulting in a significant volume of runoff being wasted. To reduce this problem, regular dredging of reservoirs and riverbeds, erosion control in upstream areas, and sediment monitoring are essential. Implementing these measures can prevent the loss of millions of cubic meters of water every year and extend the useful life of dams.
Simple Solutions for Dredging and Preventing Water Loss, with Priority Given to Community Investment
- Periodic Manual and Mechanical Dredging
In small areas and shallow rivers, manual dredging can be carried out with the assistance of local communities and volunteers. This approach is relatively low-cost and can help preserve reservoir capacity and maintain the free flow of water.
- Controlling Soil Erosion Upstream
Planting trees and vegetation in watersheds, preventing inappropriate agricultural practices, and stabilizing soil can reduce the amount of sediment entering rivers. Local residents and farmers can participate in these efforts.
- Establishing Local Funds for Maintenance and Dredging
Establishing community-based funds to finance dredging and water-resource maintenance can be an effective way to attract local investment and encourage participation in resource protection.
- Use of Nanobubble Technology
Nanobubble technology, which generates extremely small air bubbles in water, can contribute to water treatment and quality improvement and may help reduce suspended sediments. This technology has recently been adopted in some countries and has the potential to reduce sedimentation and improve reservoir efficiency. In Iran, however, although it has been implemented in certain areas, it is still at an experimental stage in this particular context and requires greater support and investment.
