Storm sewers are widely used to carry away runoff from storms, primarily in urban areas.
Storm sewers are widely used to carry away runoff from storms, primarily in urban areas. The hydraulic design begins after the locations of the manholes for the system have been determined. Between each pair of manholes the storm sewer will have a constant slope and diameter. The hydraulic design process results in determination of an appropriate diameter and slope for each length of storm sewer and determines the depth of the bottom of the pipe at each manhole. The overall procedure and each step will be presented and discussed. Example calculations for a single length of storm sewer between two manholes will be performed and an example of calculations between successive manholes will be done using Excel.
Topics: determine the value for runoff coefficient for a drainage area with known land use, SCS soil group, and approximate surface slope. find the rainfall intensity for specified storm duration and return period at a specified location if given an I-D-F table or graph for that location. estimate overland flow travel time for a drainage area using the Manning Kinetic equation. estimate channel flow travel time using Manning’s Open Channel Flow Equation. estimate peak runoff rate from a drainage area using the Rational Method. use Method I and Method II as outlined in this course to calculate design diameter and slope for a length of storm sewer between two successive manholes. determine the velocity and flow rate in a circular pipe flowing partially full if enough information is available to calculate the full pipe velocity and flow rate. put together the above skills to carry out the overall hydraulic design of a length of storm sewer between two successive manholes. use Excel to make storm sewer hydraulic design calculations for lengths of storm sewer between successive manholes.
Intended Audience: hydrologists, civil engineers, hydraulic engineers, highway engineers and environmental engineers. Publication Source: Harlan H. Bengtson, PhD, PE
Dr. Harlan Bengtson is an online PDH course provider of continuing education courses for professional engineers. Dr. Bengtson is a graduate of Iowa State University with B.S. and M.S. degrees and of the University of Colorado with a PhD. He is a licensed Professional Engineer in Missouri. Dr. Bengtson has spent 30 years in engineering education in teaching and administrative positions, including six years as Dean of Engineering at Southern Illinois University Edwardsville. Dr. Harlan H. Bengtson, PE 33 Grainey Drive Glen Carbon, IL 62034 Phone: (618) 406-6892 E-mail: hnkbengtson@yahoo.com PROFESSIONAL PROFILE Dr. Bengtson is a graduate of Iowa State University with B.S. and M.S. degrees and of the University of Colorado with a PhD. He is a licensed Professional Engineer in Missouri. He has spent 30 years in engineering education in teaching and administrative positions, including six years as Dean of Engineering at Southern Illinois University Edwardsville. His areas of expertise are environmental engineering, hydrology and hydraulics, engineering science and renewable energy systems. He has done regular consulting work while holding the academic positions. Prior to entering academia, Dr. Bengtson worked for Minnesota Mining & Manufacturing as a Product Development Engineer and for E. I. duPont deNemours as a Process Development Engineer. Dr. Bengtson has authored numerous publications, presentations and technical reports. He is currently active as a freelance technical writer, author of continuing education courses for Professional Engineers, and is the founder of www.engineeringexceltemplates.com and www.EngineeringExcelSpreadsheets.com, sites with the objective of providing inexpensive, easy to use Excel spreadsheets for a variety of engineering calculations.
