Colombo, the largest city in Sri Lanka, has expanded rapidly and continuously since the local economy was opened in the early 1980s. As a contrast to the other cities in the region, one of the main issues that planners have observed with current urbanization pattern was the slow growth of population density in the region to sustain reasonable economic growth that can support modern transportation and other infrastructure. The new Western Region Megapolis Project (WRMP) is attempting to develop a cluster of urban centers connected with modern transportation network. According to the proposed development plan, a cluster of urban centers expected to create an urban development pattern with better territorial balance. The objective of the proposed strategy is increasing the current population base by stimulating migration to the region. The plan has an ambitious goal with an estimated population of 8.5 million by 2030 with 3 million increases. The strategies proposed in the WRMP to attract population to peripheral urban centers are improving connectivity and creating job opportunities by way of increased investments. This research demonstrates a methodology to evaluate urban planning scenarios arising from policies of in the WRMA proposal using CA model and a Latin Hypercube Sample design. This method is useful in situations where the availability of reliable socioeconomic data is not available for data-intensive simulations.