Flood River Modelling 1D & 2D

• Creating a development within the flood zone which has not been modelled by the Environment Agency

• Building a flood protection wall or bund around your property or asset

• Determining the final floor levels of properties to protect them against flooding

• Improving the surface network such as pipe and ditches to create a more resilient developments

• Determining the climate change impact on your development or asset

• Creating safe access and egress routes

• Installing critical assess that require failure impact assessments

1D river modelling

1D river models represent the flow along the watercourse. 1D river modelling is used when:

• The river has a channel as a similar cross section along the area of study

• The flood zone has the same shape along the cross section

• Substantial area of rivers are culverted or channelised

• There is an obstruction that cause the flow to back-up for example culverts, bridges and weirs.

2D river modelling

2D river models allow for the complete representation of the flow regime within the flood plain. It contains the ground surface including its elevation with x, y and z coordinates. The river modelling principles:

• Flow hydrographs derived from the FEH hydrological study

• It is based on digital terrain models (DTM). DTM excludes trees, vegetation and buildings while these are included within DSM data

• Combines 1D within the model

• Provides a complete understanding of the flood zone and its interaction with the river channel

What you expect from us

• Fixed fee for our work

• Excellent communication with the environment Agency

• Complete walk over surveys of watercourse

• Plan, organise and supervise topographical surveys

• Fully complaint model to the Environment Agency standards

Advantages of using our river modelling expertise

The benefits of using our flood river modelling services:

• Increasing the accuracy of the flood extent, levels, velocity and their impact to your development

• Creating a more resilient development by providing clearly understanding the duration, flow paths and hazard of the flood event within the development

• Providing a better rational to management of flood risk within the catchment

• Helping to highlight the development sustainability and safety over its lifetime

• Providing greater support for sequential and exception tests

• Allowing to fully integrate Sustainable Drainage Structures within the flood zone and its impact on flooding

• Providing detailed velocity and flood depth information that inform evacuation plans

• Ensuring that the access and egress routes within the evacuation plans remain safe in the event of a flood.

Is a detailed river modelling always required if the flood extent and levels are not available?

In some cases an intermediate assessment method as per the Environment Agency guidelines. This method is only applicable for areas where the climate change allowance gives a substantially high final floor level that the development is impracticable to deliver.

The use of this method should be agreed with the Environment Agency in advance.

Call Arge on 01608 510 121 or e-mail him at arge@rida-reports.co.uk

Arge Rivera

BEng(Hons) MSC CEng MICE MCIWEM C.WEM CEnv