Programme Overview
This workshop takes participants from the fundamentals of open channel flow theory through to the construction, calibration, and professional application of both 1D and 2D hydraulic models using HEC-RAS 6.x — the most widely used hydraulic modelling platform on infrastructure projects in Nigeria and globally.
The second half of the course introduces EPA SWMM for urban stormwater and drainage network design — a critical competency for road, estate, and urban infrastructure engineers. Participants complete the course having produced a flood inundation map and a fully designed urban drainage network, both drawn from real Nigerian project data.
"The 2D HEC-RAS module changed how we approach flood risk assessment. We now produce inundation maps in hours rather than days — maps that clients and regulators accept for design sign-off." — TierraSYNC hydraulics team
Daily Course Schedule
01
Open Channel Hydraulics — Theory & HEC-RAS 1D Setup
- Morning: Review of open channel flow fundamentals — Manning's equation, specific energy, critical flow, hydraulic jumps, normal and critical depth; gradually and rapidly varied flow profiles (M1, M2, S1, S2, C); subcritical vs supercritical flow; energy and momentum equations; flow controls and boundary conditions
- Afternoon — Practical: HEC-RAS 6.x interface orientation; creating a new 1D project; importing terrain from QGIS / RAS Mapper (SRTM, Copernicus DEM); cross-section editing and interpolation; Manning's n selection for Nigerian channel and floodplain conditions; setting upstream/downstream boundary conditions (normal depth, known water surface, flow hydrograph); running steady-state and unsteady simulations
- Hands-on exercise: build and run a 1D HEC-RAS model of a Nigerian river reach with a designed spillway structure
02
HEC-RAS Structures — Bridges, Culverts & Inline Weirs
- Morning: Bridge hydraulics — pressure flow, weir flow, low flow computations (energy, momentum, Yarnell, WSPRO methods); bridge scour estimation (HEC-18); culvert hydraulics — inlet and outlet control, box and circular culverts, multiple barrels, sag culverts; HY8 culvert analysis and design; inline structures — weirs, gated spillways, dam breach modelling
- Afternoon — Practical: Add bridge and culvert data to Day 1 HEC-RAS model; compare hydraulic analysis methods for bridges; design a box culvert for a 50-year design flood; model a gully erosion check dam as an inline weir; interpret output water surface profiles and identify overtopping risk
- Hands-on exercise: analyse hydraulic adequacy of an existing road culvert and design a replacement for a 25-year storm
03
HEC-RAS 2D Modelling & Flood Inundation Mapping
- Morning: Introduction to 2D hydraulic modelling — when to use 2D vs 1D; 2D flow equations (shallow water equations, diffusion wave); mesh generation in RAS Mapper — structured and unstructured (polygon-based) meshes; breaklines, refinement regions, and mesh quality; terrain integration; 2D boundary conditions and initial conditions; Manning's n for 2D domains (raster-based from land use)
- Afternoon — Practical: Build a 2D HEC-RAS model of a Nigerian floodplain using Copernicus DEM; create and refine computational mesh around structures; run 2D unsteady simulation with design flood hydrograph from HEC-HMS; produce flood depth, velocity, and inundation extent maps in RAS Mapper; export flood polygon to GIS; overlay with infrastructure and population data
- Hands-on exercise: produce a 100-year flood inundation map for a river reach with inhabited floodplain — the standard deliverable for ACReSAL and NEWMAP flood risk studies
04
Urban Drainage Design with EPA SWMM
- Morning: Urban hydrology — rational method and SCS CN for urban catchments; impervious cover and runoff coefficients; inlet time and overland flow; SWMM model structure — sub-catchments, junctions, conduits, outfalls, storage units, pump stations; design storm selection for urban drainage (local IDF curves); drainage network layout principles for Nigerian township road projects
- Afternoon — Practical: Set up an EPA SWMM model for a 20 ha urban catchment (road with side drains, cross drains, and outfall); define sub-catchment parameters (width, slope, imperviousness, Manning's n, depression storage); input design storm hyetograph; run dynamic wave simulation; check conduit surcharge and surface flooding; resize drainage channels to eliminate flooding; produce a drainage report summary
- Hands-on exercise: design a complete stormwater drainage system for a typical Nigerian township road segment
05
Water Supply Networks with WaterGEMS & Integrated Project Workshop
- Morning: Introduction to pressurised pipe network analysis — Hardy-Cross, Newton-Raphson methods; WaterGEMS interface; building a simple water distribution network; demand allocation, pressure zone management, fire flow analysis; pump curves and head-discharge relationships; energy and pressure gradient lines; water quality basics (age, chlorine decay)
- Afternoon — Project Workshop: Integrated case study — trace a complete hydraulic workflow from HEC-HMS catchment model → design flood hydrograph → HEC-RAS 1D/2D flood routing → flood inundation map → SWMM drainage design. Discuss real lessons from TierraSYNC Katsina drainage supervision and dam spillway projects; participant model review and critique
- Certificate presentations; Q&A and course debrief
Software & Data Requirements
- HEC-RAS 6.5+ — free from USACE Hydrologic Engineering Center (64-bit Windows required)
- EPA SWMM 5.2+ — free from US EPA website
- HY8 2.2+ — free FHWA culvert hydraulics software
- QGIS 3.34 LTS for terrain preprocessing and output mapping
- WaterGEMS trial version (30-day activation provided) or OpenFlows WaterGEMS student edition
All DEM data, cross-section survey files, design storm inputs, and catchment shapefiles are provided by TierraSYNC. A 16 GB USB drive is issued to each participant on Day 1.
Who Should Attend
- Drainage and flood control engineers on road, urban, and water sector projects
- Engineers involved in dam spillway design, flood risk assessment, or dam break analysis
- Engineers on World Bank programmes (ACReSAL, NEWMAP) requiring hydraulic design deliverables
- Municipal engineers and urban planners responsible for stormwater master planning
- Postgraduate students in hydraulics, environmental, or water resources engineering
Recommended prerequisite: The Hydrological Modelling course or equivalent experience in design flood estimation. Participants should be comfortable with Windows software and basic spreadsheet use.