Impacts of Wastewater Management and Enhancing the Landscape of the Mae Kha Canal: A Quasi-Experimental Study

The Mae Kha Canal in Chiang Mai, Thailand, has long suffered from severe water quality deterioration due to rapid urbanization, population growth, and inadequate waste management practices. This article describes an integrated water resource management approach, started in February 2018, with the goal of guaranteeing sustainable urban living conditions and improving the water quality of the canal. This study was a quasi-experimental study, with key interventions including garbage net installation, coconut-fiber mattress weir installation, and Free Water Surface Wetland treatment using vetiver grass. An interrupted time-series analysis of the monthly biochemical oxygen demand (BOD) and dissolved oxygen (DO) levels were applied to examine the trends and changes after the full implementation of wastewater management in March 2021. The results demonstrated significant improvements in water quality, indicated by reduced BOD levels (from 17.00–38.70 to 9.00–12.67 mg/L) and increased DO levels (from 0.00–2.40 to 0.80–6.00 mg/L). However, the decreases in BOD and increases in DO levels were not stable during the year. The post-intervention trend of BOD level decreased after the wastewater management implementation at SriDonChai Road (coefficient of trend: = −0.75 [95% confidence interval: −1.44 to −0.06]). This project highlights the effectiveness of integrated management strategies in addressing urban water quality issues and emphasizes the importance of community involvement in sustainable environmental management. The findings underscore the necessity for integrated approaches to wastewater management in urban environments to address both ecological health and public welfare.