Rainfall-runoff analysis in evaluating storm drainage systems

This study is focused in analyzing the responses of an existing storm drainage system under a five and ten-year storm using the hydrograph method (SCS Dimensionless Unit Hydrograph Approach) as mean of analysis. Particularly, the subject is an open canal drainage system serving a 45,968 square meter residential and semi-commercial subdivision located at Barrio Matalahib, Tarlac, Tarlac. The capacity of the existing system was estimated to a maximum value of 99.90 cubic feet per second. It was found to inadequate to carry the maximum peak flows of a five year storm ranging from 22.76 cfs to 119.58 cfs. Estimated flood depths were mapped showing different depth increments and reaches. It was also found that to be able to minimize flooding, the design of the existing system should be improved. This study depends on the basic assumptions such as soil types, housing frontages and others. It was highly recommended to further emphasize on these parameters by performing actual experiments and extensive researches