## 3 Results and Discussion
### Analysis of Model Optimization Results
#### 3.3.2 Socio-Economic and Policy Implications  
(1) Cost-Benefit Analysis  
Implementing the proposed drainage network optimization and low-impact development (LID) measures entails significant upfront investment. For instance, constructing rainwater storage ponds, permeable pavements, and rain gardens involves material, labor, and maintenance costs. However, the long-term benefits far outweigh these initial expenditures. By reducing waterlogging events, the study predicts a 63.88% reduction in drainage system failure rates, which translates into decreased economic losses caused by property damage, traffic disruptions, and lost productivity. Additionally, improved groundwater recharge and rainwater utilization reduce the demand for municipal water supplies, offering further cost savings over time.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Component**} & **Design Area** **(m2)** & **Infiltration Rate (mm/h)** & **Soil/Material Porosity (\%)** & **Water Capacity (m3)** & **Additional Details** \\ \hline Permeable & 5000 & 20 & 40 & \(\backslash\) & Permeable concrete and bricks used \\ \hline Rain Garden & 200 & 30 & 45 & \(\backslash\) & Plant species: drought-tolerant grasses and shrubs \\ \hline Rainwater & 5000 & \(\backslash\) & \(\backslash\) & 5000 & Includes filtration and purification systems \\ \hline \hline \end{tabular}
\end{table}
Table 5: Parameters for drainage components.  
(2)  
Stakeholder Engagement Challenges  
Successful implementation of these measures requires coordinated efforts among multiple stakeholders, including local government authorities, residents, businesses, and environmental organizations. One major challenge is raising public awareness about the importance of LID measures and maintenance requirements. For example, ensuring the long-term effectiveness of rain gardens and permeable pavements depends on community involvement in regular cleaning and maintenance.  
Moreover, conflicting interests among stakeholders may arise. Businesses in densely populated areas might prioritize minimizing disruptions during construction, while government bodies may focus on achieving long-term ecological benefits. Establishing a participatory framework that includes regular consultation meetings and transparent decision-making processes is essential to address these challenges. Additionally, incentive programs, such as tax rebates for businesses that adopt onsite LID measures, could encourage broader participation.  
(3) Policy Recommendations  
Integrating the proposed drainage and LID solutions into existing urban planning frameworks is critical. Local governments should update building codes to mandate the use of permeable materials in new construction projects and incentivize the retrofitting of existing structures. Furthermore, developing funding mechanisms, such as public-private partnerships (PPPs), can help alleviate the financial burden of implementation while ensuring sustainable maintenance. Collaboration with academic institutions to conduct long-term monitoring and evaluation of these measures can also provide evidence-based recommendations for policy refinement. As noted by [PERSON] et al. (2024), incorporating LID measures into urban planning not only addresses immediate flooding risks but also promotes long-term environmental benefits [38].