Analysis of Vulnerability Types in Small-Scale Reservoirs

With the development of technology, many reservoirs have been newly established due to the construction and maintenance of water supply facilities since the 1910s. However, as the number of reservoirs more than 50 years old increased rapidly in recent years, there is a growing need for proper repair, reinforcement, and continuous maintenance of deteriorated structures. As of 2021, the Korea Rural Community Corporation conducted a precise safety diagnosis for reservoirs with a total storage capacity of 300,000 tons or higher. In contrast, the remaining reservoirs required a periodic safety inspection rather than a precise inspection unless there were issues on those facilities. However, most of the small agricultural reservoirs were managed by local governments, so facilities were not managed in good condition due to lack of reliable budgets and engineers. Therefore, this study aimed to analyze the types and causes of damage of small-scale reservoir for proper maintenance tasks based on the safety inspection data compiled from 300 agricultural reservoirs with a storage capacity between 50,000 and 300,000 tons. From a series of analyses on those 300 reservoirs, we found that the top five damage were settlement and scour, delamination/delamination, spindle corrosion, efflorescence, and vegetation. Specifically, the types of damage originated mainly from irregularities on the dam crest, vegetation on the upstream slope, settlement and scour on the downstream slope, peeling and peeling on the access channel, control unit, and waterway, spindle corrosion on the dam ridge, and vegetation on the diaphragm. The dam crest with high management factors, the access channel and waterway with high construction factors, and the upstream slope, downstream slope, and colic with high environmental causes were also identified as the main causes of damage. These results revealed that effective maintenance plans and schedules should be determined based on vulnerability types on the reservoirs, in addition to other considerations such as economic feasibility.