The Ría de O Burgo estuary in A Coruña, northwest Spain, has long experienced severe degradation from industrial and urban effluents, compromising sediment and water quality as well as local fisheries. To restore this critical environment, an extensive dredging initiative removed 583,337 m3 of sediment, of which 174,284 m3 contained high levels of contaminants requiring special handling. Central to the remediation was Spain’s first major application of geotextile dewatering tubes for large-scale sediment management. Two on-land enclosures lined with HDPE membranes housed 121 dewatering tubes arranged in multiple layers, effectively containing dredged sediments pumped directly from the estuary. A 0.1% dose of cationic polyacrylamide flocculant promoted rapid and efficient dewatering, maintaining turbidity below 10 NTU and residual flocculant concentrations under 2 µg/L. Despite site challenges including weak soils, tidal fluctuations of up to 4.5 m, and limited construction space; continuous monitoring, stakeholder engagement, and adaptive management ensured compliance with strict environmental regulations. Beyond achieving a high-quality effluent and isolating contaminated sediments, the reclaimed land offers potential for public space and ecological restoration. This successful case study underscores the reliability and versatility of geotextile dewatering tubes on soft substrates, setting a precedent for integrated dredging and land reclamation initiatives worldwide.