With over ten years of experience, hydraulic modelling is at the heart of Lutra Consulting's history. We work with private and public sector clients to deliver projects, both small and large, in the UK and abroad.
Our background in engineering, software development and GIS allow us to deliver projects of all sizes innovatively and efficiently.
With the introduction of the Water Act 2003, reservoir undertakers are required to produce reservoir flood plans for their statutory reservoirs, leading to a marked increase in demand for Dam Break analysis.
Our staff were involved with the development and testing of the modelling specification used on the Environment Agency's national RIM (Reservoir Inundation Modelling) project and are aware of both the requirements for dam break analysis and the limitations of modelling packages used for this task.
Breach models are used to assess the risk associated with a failure of defences during a flood event. Breach models are usually purely 2D models which can be built comparatively quickly and take into account the momentum of water escaping through the breach, leading to accurate approximations of flood velocities and depths and therefore flood hazard.
Fluvial models (considering flooding originating from rivers) may be 1D, 2D or linked 1D/2D and are used to determine Environment Agency flood zones, test flood mitigations, floodplain compensation schemes, flood alleviation schemes and for many other purposes.
With experience ranging from broad-scale catchment flood management plans (CFMPs) to detailed design-led studies, we use the following packages:
- ISIS & ISIS 2D
- TUFLOW & ESTRY
- InfoWorks RS/CS
- MIKE 11
Pluvial, or direct-rainfall modelling applies a rainfall event to the model itself rather than applying inflows derived from a hydrological model. Direct-rainfall models allow more control over spatially varying infiltration rates and often include a representation of the surface water drainage network.
Direct-rainfall models are often used to assess the flood risk arising from surface water flooding and usually contain a higher level of detail than fluvial models, sometimes even including details of kerb heights.
Coastal modelling is used to assess flood risk associated with a combination of tides, storm surges, wave overtopping and sea level rise.
Coastal models are often well suited to modelling packages featuring irregular meshes due to the large study areas involved.
Large-scale and national studies can require thousands of individual models to be built, often taking years of computational time to run.
With national-scale experience in reservoir inundation, canal embankment breach, pluvial and fluvial modelling, Lutra Consulting specialise in efficiently undertaking large-scale studies through a combination of automation and parallel computing.
Tasks that can be automated include:
- Pre-processing input data
- Constructing models
- Simulation management (scheduling simulations over a cluster of machines)
- Post-processing results
Tailored to supporting water engineering consultancies, our services cover the entire modelling process, from concept review to final handover, allowing our experience to add additional value to our clients' modelling teams and projects.
A concept review should take place at the beginning of a modelling project before the schematisation process has begun. Concept reviews ensure modelling projects meet budget and program constraints by reducing the likelihood of having to make fundamental changes to the model schematisation at late stages of the project.
A concept review will examine the choice of modelling software, placement and type of boundary conditions, method of schematisation and many other aspects to ensure the proposed modelling methodology is both fit for purpose and likely to produce a stable, robust model.
Project risk is reduced by having a clear, sensible methodology in place from the start, reducing time that may have otherwise been spent diagnosing problem models or reproducing modelling outputs after making large changes to the model schematisation.
Benefits of concept reviews include:
- Reduced risk of budget overspend
- Reduced risk of missing deadlines
- Reliable results and low mass-balance error
- Models that are more likely to be accepted during external review
- Stable models
- Reduced stress on modelling staff
An independent review should be carried out to ensure that a model is both fit for purpose and produces sensible results. A model that runs to completion does may not necessarily be fit for the purpose it was intended or adequately represent reality.
Our experience is built upon years of providing internal model reviews as well as independently reviewing models on behalf of the Environment Agency.
We specialise in:
- Ensuring models are fit for external review before their submission
- Independently reviewing models on behalf of the Environment Agency
- Reviewing flood risk assessments and supporting modelling on behalf of stakeholders
Most hydraulic modellers have experienced the stress of tight project deadlines and a model that either fails to run or produces poor results. Diagnosing and amending problematic models can be a lengthy process, consuming a significant amount of project budget. Although software vendors provide support for their modelling software, most are not obliged to fix problematic models.
Lutra Consulting offer a dedicated service for diagnosing and fixing problematic models. Our staff are experienced senior modellers with a history of providing technical support for both ISIS and TUFLOW in the UK and are able to diagnose and resolve problematic models efficiently with a quick turnaround.
We specialise in:
- Diagnosing unstable models that fail part-way through a simulation
- Diagnosing problematic linked 1D/2D models
- Creating reliable initial conditions for models that fail to run
- Locating the source of oscillating results
- Addressing poor mass conservation
We support the following packages:
- ISIS 2D
- TUFLOW (and ESTRY)
For assistance or further information, please contact us.