174. Sediment Induced Abrasion in Hydraulic Structures and Equipment – Bhutan's Experience

The Himalayan region is prone to high levels of siltation, especially during the monsoons, when torrential rain waters eat away into the young geology of the mountains. The resulting scoured silt and debris is washed down into the rivers. These are the very rivers that provide the Himalayan region with such a huge hydropower potential. Siltation substantially increases operation and maintenance costs of hydropower stations through more frequent and higher degrees of wear and tear to underwater parts and other hydraulic structures, damage to civil structures such as the dam glacis, clogging of cooling water systems, and sediment filling of reservoirs. In Bhutan, it is no different. Even though Bhutan has had a very short association with hydropower compared to most countries, Bhutan has faced severe problems due to siltation and silt in its rivers. Implementing effective means of managing sediment are a major concern to all operating stations and associated with the wherewithal are the high costs.