Urban Drainage Design: Pavement, Gutters, and Roadside Channels

This course covers the hydraulic design of roadway pavement drainage and roadside conveyance systems, drawing from Chapters 5 and 6 of FHWA's Urban Stormwater Management in the United States: Hydraulic Engineering Circular No. 22 (HEC-22), 4th Edition. The course addresses design storm frequency and allowable spread, surface drainage features and hydroplaning, gutter flow equations for uniform and composite sections, and open channel flow concepts and stable channel design for roadside and median channels. Students will apply Manning's equation-based methods to size gutters and roadside channels, select appropriate linings, and evaluate channel stability under design flow conditions.

Learning Objectives

1. Define the design storm frequency and allowable spread criteria for different roadway classifications and explain how factors including traffic speed, functional class, and ponding risk govern their selection per HEC-22 guidance.

2. Apply the modified Manning's equation for triangular, composite, and V-section gutters to compute spread and flow capacity, and identify conditions that require iterative analysis or a check-storm evaluation.

3. Explain open channel flow concepts including the Froude number, subcritical and supercritical flow regimes, and hydraulic jumps, and describe their implications for the stability and design of roadside and median channels.

4. Apply tractive force theory and permissible shear stress criteria to select channel geometry, side slopes, and lining materials that maintain stable conditions under design discharges.