· · · Repository Hydraulic Engineering Reports

Prediction of wave overtopping discharges for seawalls / breakwaters have improved significantly over the last 25 years, but processes associated with overtopping hazards to people on or close behind seawalls are not yet well understood. Despite research advances in recent years, there remain important gaps in knowledge and disagreements over safe levels of wave overtopping and the composition and spatial extent of overtopping. Similarly, there are few data on the direct effects of overtopping flows. This report summarises analysis developed within the EC CLASH project on the hazards arising from wave overtopping. It identifies sources of information on overtopping hazards, and discusses the basis for assessing the consequences of overtopping. The report reviews the state of guidance in Europe, describes instances of hazard, and draws potential guidance on limits to discharge, volume, velocity and depth. The report also draws supplementary data from parallel studies on overtopping and its effects.

This report describes research to simplify and consolidate the prediction of wave action in reservoirs; to calculate wave induced discharges on embankments; and to extend work on blockwork and slabbing protection for dam faces presented by Herbert et.al (1995) in the companion report SR 345. The report should be used by engineers involved in the inspection, analysis, design and construction of block revetmetments and slabbing protection against wave attack of faces of embankment dams or similar revetments.

In 1962 the Civil Engineering Research Association (CERA) sponsored laboratory tests which resulted in the publication of a report (1) giving design procedures for determining the riprap size required for given design wave conditions. the CERA work represents one of the first attempts to rel.te the results of tests using regular waves to those using irregular waves (laboratory wind generated in this instance) This relationship is a particular problem because most quantitative information on wave damage comes from laboratory generated regular waves rather than from irregular waves of the kind found in nature. Before an extension of the CERA work could be satisfactorily completed it became clear that the regular-irregular wave problem could be solved by using paddle generated, irregular waves which had meanwhile become available. Thus it was decided to take advantage of improved techniques and make a new series of tests which covered parts of hoth the original CERA research programmes, This report describes the tests and the resulting design procedures which apply to deep water waves .. Tn brief, the volume of riprap eroded was measured as a function of the number of incident Waves for each of three sizes of riprap for each of several significant wave heights at three mean wave periods. These measurements were made on slopes of J : 2, I : 3, 1 : 4 and 1 : 6 throughout the work, in the planning, execution and reporting, discussions were held with practising engineers who formed the majority of a steering group (Appendix I) set up by the Construction Industry Research and Information Association (CIRIA, successor to CERA) to guide the project

Guidance on the use of grass to stabilise surfaces subject to erosion by intermittent flow. Provides information on the erosion resistance and frictional resistance of grass. Includes recommendations on grass mixtures, etc. Extensive literature survey

Following this introductory section, Chapter 2 discusses the Samphire Hoe field measurements and results, Chapter 3 the design and operation of the laboratory measurements and the results are described in Chapter 4. Finally in Chapter 5 the data are compared and the principal conclusions are given.

Following this introductory section, Chapter 2 discusses the Samphire Hoe field measurements and results, Chapter 3 the design and operation of the laboratory measurements and the results are described in Chapter 4. Finally in Chapter 5 the data are compared and the principal conclusions are given.

DP World received approval in May 2007 to build London Gateway Port and Logistics Park. The applications were submitted in 2002 and supported by an Environmental Statement. The project went to Public Inquiry in 2003. In relation to the port the following marine works were and still are proposed: • Reclamation • New Jetty for handling aviation and bitumen fuel vessels • Quay wall for berthing of deep sea container and cargo ships • Quay wall to enable Ro-Ro ships to berth • Dredging to deepen the navigation channel Of particular relevance to the marine works is the Mitigation, Compensation, Monitoring Agreement (August 2003). The MCM was developed to secure the measures that would be incorporated into the pre-, during and post development plan. An updated version of the Environmental Statement was produced to include the updates of the Public Inquiry and Mitigation, Compensation and Monitoring Agreement (updated Environmental Statement 2004).

HR Wallingford were commissioned by London Gateway to advise on marine and coastal processes and in particular are responsible for the modelling of the impacts of the marine works to enable an understanding of impact to be developed. They have been involved in the project since 2001. The modelling, analysis and interpretation described in this report is based on the methodologies originally employed in the hydraulic studies undertaken to support the EIA. The physical impacts of the two refined scenarios "interim" and "final" have been assessed and contrasted with the "original" scenario as assessed in the EIA. The main findings are as follows: * At an estuary wide scale, no significant changes to predictions of impact on upstream tidal propagation or extent of impact of the works as a result of scheme refinements. * Minor changes to flow regime compared to original scheme. * Siltation on Mucking Flats less than for original scheme * Maintenance (mud deposition) in the original scenario was 1.7 Mm3/year: - initial refined scenario is predicted to be 2.0 Mm3/year - final refined scenario is predicted to be 1.3 Mm3/year * In neither scenario would there need to be a change to the approach to future maintenance dredging requirements as outlined in the EIA. * Maintenance (mud deposition) at nearby berths for both refined schemes is predicted to be similar to that predicted for the original scheme. It can be inferredd from these results that if the interim scheme were modified to a scenario where three container berths had been built, there would be no further change to the flow regime at the adjacent downstream berth.

The overall objective of Task 30 is to support the communication of the findings of the whole FLOODsite project and to promote uptake of the FLOODsite framework and methodologies by the three main target groups: public, professional and educational. The specific objective of Task 30 is to enhance uptake through the adoption of a Web-enabled knowledge based, modelling and dissemination platform, referred to as E-Flood. This report fulfils the obligations of Milestone 30.1, as defined in the Description of Work, which is to review the FLOODsite related software and modelling methodologies and to provide a specification for E-Flood platform.

A report describing a method for uncertainty and sensitvity analysis that can be applied within the context of flood risk analysis

This document contains all of the Task Fact Sheets produced for the FLOODsite project, with a contents and index. These fact sheets summarise the key project outputs from the FLOODsite project.

Evacuation is a response to the immediate or forecast threat of flooding that is expected to pose a risk to life, health or well-being. It involves people moving from their houses or places of business to ‘safe’ locations, out of the flood risk area where they are able to shelter until it is possible and appropriate for them to return. This report summarises the institutional and legal frameworks for a number of European countries. The report details the user requirements with respect to evacuation planning for flood emergencies based on consultation with a number of stakeholders in France, Germany, The Netherlands and the UK. The following generic conclusions have been reached regarding evacuation planning and emergency management of floods: • The timing, speed and method of communication of reports are critical to effective emergency management during a flood • A knowledge of the road network, location of the vulnerable elements at risk and evacuation times are key to evacuation and emergency planning • More robust and integrated communication links between the organisations involved in the response during a flood helps to ensure an effective response • A flood event management system that provides estimates of flood extents and depths for breach scenarios would assist with emergency response • Organised evacuation is only used as a form of emergency response in very rare circumstances. In most of Europe the authorities have no powers to forcible evacuate people from their houses during floods • There is need for tools and methods to assist in the planning of evacuation/rescue operations and to estimate the optimal use of the transport network and the time required for execution of an evacuation • There is little experience within the European Union (EU) with methods and models to support the planning and execution of evacuation and rescue operations related to floods.

This report provides an overview of the state of the art with regards to embankment breach initiation and formation processes. Basic breach formation processes are explained, including a review of commonly held misconceptions. The different stages of breach initiation and formation are also explained, along with the varying needs of different end users, and hence the significance of the different stages of breach and the importance of understanding uncertainty within the different stages of breach prediction. Different types of breach model, from simple empirical formulae through to complex, predictive physically based models. Current capabilities and research initiatives related to each are summarised, identifying current best practice and current data sets available for model validation. Perceived gaps and priorities for future development supporting the improved reliability of breach prediction are then summarised.

This report is the deliverable from the FLOODsite partners contributing to Task 5. Research has been undertaken to improve understanding, models and techniques for the analysis of the performance of the whole flood defence system and its diverse components, including natural and man-made defences (e.g. seawalls, embankments, dunes). In particular, two specific aims were to (a) to develop an improved understanding of morphological change of beaches over large time and spatial scales and provide a better predictive tool for the response of dunes to storm loading, and (b), to critically review current knowledge and on-going programmes or river and estuarial morphology, summary existing knowledge and identify a forward programme of detailed and justified research.

A number of methods of joint probability analysis are set out and contrasted. The methods are applied to the dependence between a number of variable-pairs relevant to flood risk in the UK, for example wave heights and sea levels for coastal flood risk, and river flow and sea level for river flood risk. The dependence results are mapped around the UK for use in subsequent site-specific coastal engineering studies.

This report provides an overview of the technical work undertaken by the partners under FLOODsite Task 6. The research in Task 6 addresses breach initiation and growth. Research was undertaken to (i) investigate and develop preliminary models for predicting wave induced breach initiation (ii) investigate soil processes, review and refine the HR BREACH predictive model (iii) extend the existing model by Visser to predict breach through cohesive materials and develop associated simplified equations for breach prediction.

This report is Deliverable 18-2 which describes the conceptual, methodological and technological frameworks and how these are implemented for three pilot sites - the Thames, Schelde and Elbe - through prototype decision or ‘discussion’ support tools. The report describes the generic interactions between all relevant factors that drive and influence flood risk management in the long term and how these may be enacted within the three prototype DSS tools.

The IMPACT Project (www.impact-project.net) provided valuable data on breach formation processes. Five large scale field tests were performed in Norway, and a further 22 laboratory tests were performed in the UK. A review of this data has been undertaken to support breach model testing and development under Task 6.

This Final Management Report for the FLOODsite Project provides a summary of the resources and expenditure over the whole project. Detailed information on the costs is contained in the cumulative tabulations presented in the Year 5 Periodic report (T35-09-11) and are not repeated here. Details of the individual Partner Institution resources are contained in a separate Annex (report T35-09-14). This management report does not cover the progress of the project science, this is reported separately in the Publishable Final Activity Report (T35-09-09) and the Annual Activity report for Year 5 (T35-09-05) the latter report identifies that all the Deliverables of the Contract were achieved. Key messages from this final Management Report are: At the outset of FLOODsite, a total of 1421 person months were scheduled for completion of the project and the total EC grant to the project budget was set in the contract as €9.68 Million. By the end of Year 5 a total of 1725 person-months have been declared which is 121.4% of the originally planned project total. This is in line with the amount of effort anticipated at the end of Year 4. The “EC” costs1 incurred by the Consortium during the project amount to 105.6% of the maximum Commission grant to the budget and the Consortium anticipates that the grant payable will be restricted to the maximum amount of €9.68 Million. The Consortium has declared “Management Costs” of 6.946% of the maximum grant, which lies just within the 7% maximum allowance. The Management Costs include the fees paid by partners for external financial audit of their project expenditure as required by the Contract. The report concludes with a discussion of our experience of the process of procurement and management of the project. The points made here may be of value in the commissioning and management of similar large scale interdisciplinary, integrated research projects in the future

This document outlines definitions of flood risk terms to used within the FLoodsite Project.