Thane city in the state of Maharashtra is successfully building resilience to the annual flooding and waterlogging events that it experiences, with the help of an early flood warning system called the Thane Urban Flood Alert Network or TUFAN.

A densely populated and rapidly growing city in the Western Ghats, Thane is sandwiched between hills and submersible marshland along the Thane Creek and Ulhas Riverbank. The city is highly vulnerable to floods and inundations, due to the high runoff during short-duration high-intensity rains and high tide conditions in the estuary and creek. Thane’s proximity to other urban/peri-urban areas in the catchment with limited water retention capacity exacerbates the flooding risk.

As a countermeasure, the Thane City Corporation has deployed TUFAN, an Internet of Things (IoT)-based early flood warning system, to monitor rainfall, the water level of creeks and drains, and tides and for updates to help plan and prepare for such disasters.

TUFAN

TUFAN, which has been deployed under the Urban-LEDS II project, was conceptualized and deployed on ground by the Thane Municipal Corporation (TMC) and ICLEI South Asia. The Urban LEDS II project was funded by the European Union and implemented by UN-HABITAT and ICLEI – Local Governments for Sustainability.

The objectives of TUFAN were to:

• Develop a real- time early warning system to enable swift response by the city administration and citizens
• Enhance resilience by reducing the impact of floods and associated damage to/ loss of property, infrastructure and human health and environment
• Use IoT-based smart solutions for effective sensor-based systems in climate-vulnerable urban areas

Key activities conducted for planning and feasibility assessment, and supply and installation of sensors at the selected locations were:

• Feasibility studies for data analysis of drain catchments, rainfall trends and catchment delineation for selected vulnerable areas.
• Identification of six locations (Saket, Gaymukh, Hiranandani Estate, Thana College, Vrindavan Society and Mumbra) for assessing waterlogging and flooding risks, in addition to modelling and scenario building of drain No. 3 in West Thane.
• Technical assessment for selection of appropriate technology for specific sites and to understand the threshold levels for flooding at each location.
• Implementation of pilot early flood warning system, based on real-time water levels in water bodies such as the Ulhas River Estuary, Thane Creek, stormwater drains, and to understand tidal effect and their interconnections.
• Analysis of water-level data, tidal ingress and rainfall data captured by the early warning system through pilot tests during the 2021 monsoon season.
• Integration of sensors with Thane city’s Integrated Command and Control Centre for effective monitoring and management. The real-time warning system comprises four ultrasonic water-level sensors, two radar-based water-level sensors and an automatic weather monitoring station.

Challenges in implementation:

• Lack of accurate real-time information, which had a bearing on monitoring, analysis and data prediction for better and adequate response
• Effective communication of information about tidal and flood risks by ensuring that all stakeholders receive and understand the message
• Improving the capacity of the staff of the concerned departments to understand and become conversant with management and operation of smart technology

Impact Assessment

• TUFAN contributes towards building climate resilience by applying IoT for early warning of flooding/waterlogging, thus reducing damage to the environment, property, infrastructure and economic and social well-being, besides loss of life.
• It helps in effective communication of information for enhanced management of waterlogging, floods and other disasters.
• TUFAN is aligned with the Smart Cities Mission in India, and supports the climate action-related schemes of Maharashtra and India’s Nationally Determined Contributions under the Paris Agreement.

List of indicative areas linked to the sensor warnings

Takeaways

• Combining structural (such as widening of drains and improved stormwater drain network) and non-structural (such as capacity training and water-level monitoring) solutions enhances urban resilience
• Comprehensive assessment of challenges, solutions, methodologies, study area and other vital factors, and finding innovative solutions improve implementation process and impact
• Effective leadership by local authorities and supportive government policies and programmes aid in efficient project implementation.

* The Urban-LEDS II project is being implemented by the TMC and ICLEI South Asia between April 2017 and December 2021, and is funded by the European Commission with support from UN-Habitat.