Excessive urbanization in the development dynamics of Makassar City in its position as the main city in the Mamminasata Metropolitan urban system has an impact on the expansion of the area towards suburban areas for the needs of new city development. The development of new cities through the development of socio-economic activities contributes positively to the quality of the environment. Increased housing development and socio-economic activities mark this condition, and urban infrastructure is allocated for new urban areas. The development of the new city area of Moncongloe-Pattalasang impacts changes in spatial attributes, spatial dynamics, and urban transportation systems based on patterns of origin and travel destinations towards the complexity of space utilization and environmental degradation from the suburbs. This study analyzes the direct and indirect effects of land cover change, land elevation, and agricultural land conversion on environmental degradation. This study uses a quantitative survey approach, and data was obtained through observation, survey, and documentation. The study results show that the development of new urban areas has positively contributed to the spatial dynamics and socio-economic system of the Mamminasata urban community. Furthermore, the difference in land elevation has positively affected changes in spatial activity patterns, environmental quality degradation, and the potential risk of urban flooding in the new city area of Moncongloe-Pattalassang. This study recommends restoring the environmental quality of new urban areas in formulating policies to support the sustainability of the Mamminasata Metropolitan urban development.