The University of Southampton

CENV6123 Coastal Flood Defence

Module Overview

This Module will introduce you to the range of skills needed in planning, managing and designing coastal defences. These skills vary from "hard" engineering to the "softer" issues of managed retreat and environmental impacts of sea level change. This module will describe current thinking and techniques used in maintaining and managing our coastline, examining the approaches used in the UK and elsewhere. The course will comprise a combination of lectures design studies, computer modelling exercises and if time and weather permit, some field visits.

Aims and Objectives

Module Aims

• Know the key issues associated with understanding flood risk in coastal regions • Understand the policy implications of planning decisions • Evaluate the economics of alternate flood defence strategies • Determine flood risk probabilities both now and in the future due to climate change • Develop and interpret hydraulic models of flooding • Design a range of flood defence barriers

Learning Outcomes

Knowledge and Understanding

Having successfully completed this module, you will be able to demonstrate knowledge and understanding of:

  • Coastal flooding and defence management issues
  • Frequency analysis of extreme events. Economic evaluation of flood damage
  • Hydraulic modelling of channels and simple structures such as gates and weirs
  • Role of regulatory agencies in the UK (DEFRA, Environment Agency, Local Authorities)
  • Types of flood defences, choice of and design of defence types. Other management options such as managed retreat
Subject Specific Intellectual and Research Skills

Having successfully completed this module you will be able to:

  • Assemble knowledge on flood defence and management strategies
  • Select appropriate strategies for coastal management and flood defences
  • Perform economic and hydraulic calculations
  • Select suitable flood defence structures
  • Demonstrate through the design exercise a coherent understanding of techniques
  • Demonstrate ability to work with quantitative and qualitative models
  • Analyse data using appropriate processes
  • Review coastal management options
Transferable and Generic Skills

Having successfully completed this module you will be able to:

  • Problem analysis and problem solving
  • Numeracy and modelling
  • Communicate effectively
  • Accuracy of problem analysis and problem solving
Subject Specific Practical Skills

Having successfully completed this module you will be able to:

  • Calculate extreme tide levels and river flow volumes
  • Perform simple hydraulic modelling with software such as HEC RAS
  • Build simple computer based hydraulic models
  • Carry out economic evaluation of flood damage
  • Specify appropriate flood defence strategies
  • Analyse existing data and apply this in a design exercise
  • Appraise flood risk both qualitatively in terms of extent and quantatively in terms of flood depths and economic damage


INTRODUCTION TO COASTAL FLOODING Overview of coastal issues. Suddenness, damage caused by saltwater and river water. Examples/case studies. Current “state of the art” and “issues” in the UK. Existence of flood risk, numbers likely to be affected. Types of flooding. Environmental impacts e.g. salt intrusion into estuaries, likely impact on sensitive areas. Planning approaches used in flood defence. Foresight implications / Making Space for water/Coastal squeeze – Shoreline Management Plans. Risk Assessment for Strategic Planning (RASP). Role of the Environment Agency, DEFRA. Economic and Financial Analysis of flood damage. HYDRAULICS AND MODELLING Frequency analysis of extreme tidal and river flood events. Impact of sea level rise on flood frequency, tidal locking, increased winter river runoff. River outlets into the sea. Description of structures such as gates, culverts, weirs. Control points and critical depth. Gradually varied flow and flow profiles, nonsteady flow, tides and hydrographs. Design Exercise Task 1: Modelling water levels in rivers and estuaries to investigate the impact of sea level rise and river floods at vulnerable sites. Identification of required elevation of flood defences using HEC RAS computer software. FLOOD DEFENCES Flood protections structures (2 hrs) a) Earth structures b) Wave recurves. Tsunamis and Tsunami Engineering (4 hrs). Numerical and Physical models in coastal engineering design (2 hrs). Design Exercise Task 2: choice of appropriate sea defences. DESIGN EXERCISE A town on the south coast of England with a known flood defence problem will be used as a case study. You will review existing flooding problems where a combination of tidal and river flood conditions exist as a series of coursework tasks. You will carry out modelling and design of existing and new flood defences and gated outlet structures, investigate existing and future flood risk and select new flood defences. The case study will include:- 1. Review of historic flood damage. 2. Understanding the existing tidal gate system, measurement of tidal levels, river flows. 3. Simulating behaviour of outlet gates with existing tides. 4. Statistical analysis of extreme tide levels, estimation of flood hydrographs 5. Use of HEC RAS to simulate non steady flow behaviour of existing gates. 6. Calculation of extreme tide and pond levels and comparison with existing defences 7. Modelling the effect of sea level rise. 8. Estimation of the effect of sea level rise on flood economic impact. 9. Design of sea walls to protect against tidal flooding. Levels, Wave actions. FIELD VISITS and GUEST LECTURES Weather and time permitting, various half day visits will be made to local and regional sites to illustrate problems and solutions. Engineers, planners and managers may give occasional guest lectures explaining current thinking and methodology in Coastal Engineering.

Special Features


Learning and Teaching

Teaching and learning methods

The module consists of a series of formal lectures, coursework lectures from visiting professionals. field visits - may include visits to Lymington, Selsey, Hayling Island, Thames Gateway.

Wider reading or practice20
Practical classes and workshops4
External visits4
Completion of assessment task16
Preparation for scheduled sessions4
Total study time150

Resources & Reading list

Software requirements. HEC-RAS

Hand-outs/ ebooks. You will be given handouts during the lectures. You do not have to buy a specific book, but you will learn much more if you obtain one of the books from the recommended book list, several of which are available in the Library. An e-book on Design in the Fluvial Environment will be made available on Blackboard.



MethodPercentage contribution
Design Exercise 10%
Design Exercise 20%
Exam  (120 minutes) 70%


MethodPercentage contribution
Exam  (120 minutes) 100%

Repeat Information

Repeat type: Internal & External

Linked modules

Pre-requisite: CENV6084 Coastal & Maritime Engineering And Energy 2016-17

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