Frequently Asked Questions

DIV Consulting is a civil engineering consultancy.  We provide a range of civil engineering services, with a focus on flood risk assessments and hydraulic modelling. 

Every proposed development must address flood risk. Best practice is to prepare a Flood Risk Assessment (FRA) as a standalone report. These reports must be prepared in accordance with The Planning System and Flood Risk Management Guidelines for Planning Authorities (2009).

The Flood Risk Management Guidelines define three flood zones: Flood Zone A, Flood Zone B, and Flood Zone C. Flood Zone A has the highest probability of flooding (1% Annual Exceedance Probability), while Flood Zone C has the lowest probability (less than 0.1% AEP).

Flood Zones only apply to fluvial (river) and coastal (tidal) flooding.

There are three development vulnerability categories: Highly Vulnerable, Less Vulnerable, and Water-Compatible development. Only specific development vulnerability categories are appropriate in each Flood Zone.

No. Residential dwellings are classified as highly vulnerable development and are not permitted within floodplain areas. In specific cases, minor developments or house extensions may be considered.

A solar farm does not fall under a single vulnerability category. 

Substations, inverters, and transformers contain electrical equipment that is sensitive to flooding and must therefore be located within Flood Zone C. Solar panels may be installed within Flood Zones A and B, provided they are elevated above the modelled flood levels and include the appropriate freeboard.

Flood guidelines state that flood risk must not be increased elsewhere. If a perimeter wall does not obstruct or divert flood flow paths, its installation may be acceptable, subject to assessment. 

We have expertise in fluvial and pluvial flood modelling. We can also assess industrial sites where there is concern about a potential containment failure of storage tanks. Hydraulic models are developed using TUFLOW and are subject to both internal and external review.

In general, fluvial flooding is modelled using coupled 1D/2D models, while pluvial (surface water) flooding is typically modelled as a full 2D (rain-on-grid) model.

Coastal flooding projects are considered on a case-by-case basis.