Innovative Underwater Maintenance: Enhancing Low-Level Outlet Repairs with ROVs and Photogrammetry

Abstract

Maintaining and repairing low-level outlets (LLOs) and intakes without upstream isolation presents a significant set of challenges, ranging from confined space risks to structural concerns and high costs associated with dewatering. Traditional methods often introduce additional complexities, underlining the need for innovative solutions that balance safety, precision, and efficiency. Integrating remotely operated vehicles (ROVs) with advanced photogrammetry offers a transformative approach to these challenges. Photogrammetry allows for the creation of highly detailed, scaled models of outlet geometries, enabling the design of custom-engineered plugs tailored to the unique conditions of each structure. These plugs, designed for mechanical integrity, provide robust human protection for downstream work without relying on inflatable or expandable systems. The precision afforded by photogrammetric modeling optimizes the sealing surface, reducing leakage to near elimination and ensuring reliability under demanding conditions. The use of ROVs further enhances this process by enabling accurate, safe placement of plugs in underwater environments that are otherwise hazardous or inaccessible to divers. This combination of cutting-edge tools minimizes environmental impacts, reduces project timelines, and enhances worker safety, all while eliminating the need for dewatering. This article explores the integration of ROVs and photogrammetry in plug design and installation, demonstrating how this innovative methodology addresses critical challenges in underwater maintenance. By showcasing its benefits, it sets a benchmark for the adoption of safer, more efficient practices in similar applications.