Surat, located at the mouth of Tapi River, has most of its catchment area lying in high variability rainfall zone. Post 1970, the city witnessed increased demand for water (e.g. industrial) and new developments along flood plain which in turn reduced the flow, leaving dam managers with no choice but to maximize reservoir storage during the monsoons. Over the last two decades, flood frequency increased due to increased rainfall variability (extreme events), especially in the river’s catchment area. Urban flooding was aggravated due to construction of embankments, bridges and land-fills in the flood plain resulting in increased afflux effects. During the tail end of monsoon, when the reservoir stores water to its maximum capacity, even a slight increase in the inflow due to severe rainfall within the catchment area forces dam managers to release high volume of water within short period of time. This leads to flooding in Surat.
This project aimed at setting up End-to-End Warning System for floods in upper and middle Tapi basin along with Khadi creek (tidal flood), to reduce the damage incurred by the city due to such emergencies. Improved reservoir operation and systems helped minimize peak floods and enabled institutions and communities handle flood emergencies better. Additional initiatives undertaken as a part of the project were:
Surat Climate Change Trust (SCCT), comprised of members from key national, state and city level institutions was established to provide a much required platform for coordination, organized information sharing and joint deliberation towards early warning provision to citizen of Surat. SCCT under the aegis of Surat Municipal Corporation installed 10 automatic weather stations and 2 water level measurement units across the city, which provides weather, tide and flow information. City level spatial data (GIS maps) and reservoir inflow and outflow prediction models were also developed, in addition to improvement of existing flood preparedness scenario in the city and action plan formalization. The developed Hydrological Model provides advance information (5 day inflow forecast) to key decision makers.