Water Quality Monitoring in Chiang Mai City Moat: A Path Towards Sustainable Development

Chiang Mai, the largest city in northern Thailand and the former capital of the Lanna Kingdom, is steeped in history and culture. Founded in CE 1296, the city was built as a walled settlement surrounded by a rectangular moat, a feature that remains central to its identity. Today, the moat and the area it encloses form the heart of the city, drawing visitors from around the world.

Despite its iconic status, Chiang Mai’s moat faces ongoing challenges from water pollution. Wastewater from buildings flows directly into the canals feeding the moat, leading to high levels of algae and contamination. While periodic water releases from the local irrigation system provide temporary relief, the water quality frequently falls to unsafe levels, threatening public health and diminishing the city’s image as a cultural and historical centre. The unchecked pollution not only harms the environment but also impacts the local economy, heavily reliant on tourism, underscoring the urgent need for sustainable management to safeguard the city’s heritage and future.

The water in Chiang Mai’s moat is refreshed periodically through releases from the Chiang Mai Irrigation Department. While the timing and amount of water released are carefully managed, the water quality itself is not closely monitored. As a result, the water quality in the moat is often rated as moderate to polluted (categories 3 to 4), making it unsafe for human use. This contamination not only harms the city’s image but also poses risks to public health by increasing the likelihood of waterborne diseases.

Recognizing the need for a sustainable solution, Chiang Mai Municipality partnered with Chiang Mai Rajabhat University (CMRU) to address the pollution issue. The university provided the scientific expertise and resources necessary to monitor and improve water quality in the moat. This partnership aimed to harness the academic knowledge of environmental scientists and students, while the municipality provided support in logistics, facilities, and local insights. Together, they saw an opportunity to not only monitor pollution levels but also engage students in hands-on learning, aligning with UN Sustainable Development Goals (SDGs) such as clean water (SDG 6), good health and well-being (SDG 3), and sustainable cities (SDG 11).

Collaboration with Chiang Mai Rajabhat University (CMRU)

The collaboration between Chiang Mai Rajabhat University and Chiang Mai Municipality, supported by START International, Inc. under the EPIC Asia seed grants program, began in September 2021. The project focused on monitoring key water quality indicators such as biochemical oxygen demand (BOD), total nitrogen (TN), and total phosphorus (TP) across four strategic points in the moat. CMRU involved students from three relevant courses—Environmental Quality Monitoring, Water Quality Analysis, and Health Behavior and Safety—to lead data collection and analysis efforts.

Chiang Mai Municipality’s Public Work Bureau facilitated the project by providing logistical support, lab access, and equipment. As part of the collaboration, students collected water samples monthly and assessed behavioral safety around the moat, gaining practical experience while helping the city solve its pressing environmental challenges. A professor from CMRU remarked, “This project allowed our students to apply theoretical knowledge to real-world problems, while also benefiting the local community.” A representative from the municipality also emphasized, “The expertise provided by the university was crucial in understanding the scope of the pollution and in developing sustainable solutions.”

The collaboration led to several actionable insights. The water quality indicators revealed high levels of contamination, particularly in total nitrogen, contributing to algae blooms and eutrophication. As a result of these findings, the municipality plans to improve its wastewater management systems, ensuring that households and businesses along the waterway treat their wastewater before discharging it. This project not only identified the main pollutants but also allowed the municipality to implement immediate measures, such as increasing the frequency of water dilutions from the irrigation system to alleviate pollution.

Moreover, the project empowered students to apply scientific methods in practical settings, strengthening the ties between academia and local governance. One student says, “Being part of a project that impacts the community directly was an invaluable experience.”

Chiang Mai Municipality and CMRU plan to continue their collaboration in monitoring water quality in the moat. Future projects may involve enhancing community engagement to prevent further pollution and implementing new technologies for water treatment. The city hopes to expand the scope of the partnership to tackle other sustainability challenges in line with the SDGs, ensuring that Chiang Mai remains a safe and attractive destination for residents and visitors alike.

Partnership Contact Information

City of Chiang Mai Contact
Mr. Trinnawat Suwanprik
Sanitary Researcher
Chiang Mai Municipality
cmsutp@gmail.com

Dr. Pimpawat Teeratitayangkul
Department of Environmental Science
Chiang Mai Rajabhat University
pimpawatt@gmail.com

Written by: Alice Murphy
Edited by: Kay Phanthuwongpakdee