Challenge: Implications for Wastewater Sludge Management Climate change is altering precipitation patterns across Europe, resulting in longer dry periods interspersed with increasingly intense rainfall events. This phenomenon, often summarized as "if it rains, it pours," significantly affects urban drainage systems and wastewater treatment processes. During extended dry weather, pollutants, organic matter, microplastics, cellulose fibers, nutrients, and sediments accumulate within sewer networks. When heavy rainfall finally occurs, these accumulated materials are rapidly washed into wastewater treatment plants in a concentrated "first flush" event. The increasing intensity of first flush events presents new operational challenges for wastewater utilities. Hydraulic peaks can overwhelm treatment capacity, while sudden surges in solids loading impact primary treatment efficiency, sludge production, dewatering performance, and overall sludge handling logistics. As climate resilience becomes a central objective for water infrastructure, understanding and managing these changing influent characteristics is essential. This paper explores the relationship between climate-driven rainfall extremes and sludge management strategies, highlighting the need for adaptive approaches that can cope with more variable and concentrated pollutant loads. Particular attention is given to the recovery and management of cellulose-rich solids captured during first flush events, which may offer opportunities for resource recovery while simultaneously reducing downstream treatment burdens. Building climate-resilient wastewater systems will require both operational flexibility and innovative technologies capable of transforming these emerging challenges into sustainable resource opportunities.