Hydraulic Performance Evaluation of the Existing Culverts for Creek Overflow Management

Culvert Capacity, Peak Runoff, Drainage Analysis, Flood Risk, Rational Method

Authors

  • Eldrick V. BITANGCOL Student, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • Christian Ray C. CONCEPCION Student, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • John Paolo C. LAUGO Student, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • Charles Matthew TUNGOL Student, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • Engr. Kevin Lester L. MABALAY Faculty, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • Engr. Amor Judith A. CABANESAS Faculty, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
  • Engr. Alelie Joy C. ALEJO Faculty, Nueva Ecija University of Science and Technology, Sumacab Este, Cabanatuan City, Nueva Ecija, Philippines
May 27, 2026
June 11, 2026

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Flooding in small catchments is often linked to inadequate drainage capacity and increased surface runoff caused by urbanization and intense rainfall. This study evaluates the hydraulic performance of an existing culvert along the Labni Creek, Penaranda, Nueva Ecija using field data and analytical methods. High-resolution topographic data were collected using RTK GNSS to define catchment characteristics such as flow paths, slope, and drainage area. The time of concentration was computed using the Kirpich equation, while rainfall intensity was derived from (Philippine Atmospheric, Geophysical and Astronomical Services Administration Rainfall Intensity-Duration-Frequency) PAGASA RIDF data. Peak runoff was estimated using the Rational Method for various return periods to evaluate the response of the catchment under different rainfall conditions. This method calculates the maximum runoff by considering the rainfall intensity corresponding to a selected return period. Results show peak discharges ranging from 4.3809 m³/s to 11.1195 m³/s for the primary catchment and 5.9643 m³/s to 15.1627 m³/s for the secondary catchment. The culvert capacity, computed using Manning’s equation, was 3.814 m³/s and 4.192 m³/s. Comparison indicates that the existing culvert is hydraulically inadequate under most conditions, posing a high risk of overflow. The study highlights the need for drainage improvements and demonstrates the effectiveness of integrating field surveying with standard hydraulic analysis methods.