What are the key considerations in the design and implementation of sustainable drainage systems $($SuDS$)$ within urban environments? Discuss the various techniques employed in SuDS, their benefits, and limitations in mitigating flood risk and managing surface water runoff. Analyze the role of vegetation, permeable pavements, detention basins, and infiltration trenches in SuDS, considering factors such as land use, soil type, and climate. Additionally, explore the challenges in integrating SuDS into existing urban infrastructure and the regulatory frameworks that govern their implementation. Evaluate the long$-$term effectiveness of SuDS in promoting urban resilience to climate change impacts and enhancing environmental sustainability, taking into account maintenance requirements, cost$-$effectiveness, and community engagement.