Assessing the Efficacy of Newly-Constructed Drainage Canals in Butuan City Proper, Philippines through Field Survey and Hydrologic Modelling Approach

Urban drainage systems play a crucial role in flood management by handling rainfall accumulation.However, the capacity of existing drainage canals to cope with water varies due to urbanization and changes in land cover, affecting runoff and infiltration rates.Researchers aimed to evaluate the maximum water volume and rainfall that newly constructed drainage canals could handle.We conducted watershed delineation to achieve this, dividing the basin into subbasins with drainage areas where rain collects and flows into outlets.Land cover and hydrologic soil groups were considered to estimate runoff and infiltration rates.Using HEC-HMS, two simulations were performed with an 18-hour rainfall to assess the capacity of the new canals.The study found that these canals could only manage approximately 667,920 cubic meters of water generated from a 43.77-mm rainfall over 18 hours.Feedback and evidence were gathered from residents to validate this finding.