WCW24

In the Spring of 2023, Lethbridge County partnered with Hydrasurvey Ltd. to formulate a comprehensive Lagoon Management Strategy, a sophisticated approach to Risk Management planning of their Wastewater Lagoons. Like many counties, Lethbridge faces the challenging responsibility of managing and upgrading critical infrastructure within constrained budgets. To effectively allocate resources, proactive planning and budgeting for projects is essential. Unlike some types of infrastructure that can be visually assessed and inspected more easily, Wastewater Lagoons present a unique challenge. Being bodies of water, problems often manifest beneath the surface, making it difficult to predict when issues will arise. To pre-emptively address significant problems in their Wastewater Lagoons, Lethbridge County engaged Hydrasurvey to conduct Bathymetric Sludge Surveys on four lagoons in April 2023. These surveys employed the latest RTK GPS mapping technology, single-beam sonar for sludge thickness mapping, manual liner measurements, and sludge sampling to determine disposal criteria. This information was presented in a comprehensive report incorporating a detailed Lagoon Management Strategy. This strategy systematically outlines the dredging and desludging priorities for each cell by ranking the lagoon's capacity occupied by sludge, estimated dry tonnes, dredgeable sludge volumes, and disposal criteria. Armed with this information, Lethbridge County was able to solicit accurate and comparable budgets from dredging contractors, specifying the volume of sludge to be dredged. The strategy also facilitates verification of completed dredging through post dredge surveys. This proactive approach, coupled with the detailed insights gained through the Bathymetric Sludge Surveys, empowers Lethbridge County to navigate infrastructure challenges with heightened efficiency and fiscal responsibility. By addressing potential issues before they escalate, the county is better positioned to make informed decisions, optimize resource allocation, and enhance overall infrastructure management.