Drainage Assessments (DA) in Northern Ireland (NI)

A Drainage Assessment (DA) is required by PPS 15 if the proposed development comprises 10 or more dwelling units, exceeds one hectare or involves a change of use exceeding 1000 square metres.  You may also be asked to provide a DA if pluvial flooding is predicted at your site or where run-off from the development may adversely impact upon other development.

We will provide you with a free lump sum quotation to undertake the DA and will not add any additional costs at a later stage. We will meet your deadline and we will revise the DA report for free if required by Rivers Agency. Our DAs are tailored to the project, minimising necessary mitigation measures and optimising the area of the site that can be developed.

We will visit the site, assess it for fluvial, pluvial and historic flooding, produce a DA report in compliance with PPS 15 and seek agreement with Rivers Agency, holding meetings with Rivers Agency and Planners as necessary at no extra cost.

In order to avoid your development increasing the risk of flooding elsewhere, you may be required to throttle the rate of surface water discharge from the site. While some other consultants are simply stating that you need to achieve a particular discharge rate in their reports, our fee includes a preliminary design of the storm drainage system in accordance with the SuDS Manual and is optimised specifically to your site.

As part of our lump sum fee, we will also submit a Schedule 6 application to Rivers Agency to acquire permission to discharge surface water from the site or prepare a PDE application for you to submit to NI Water. Finally, we will guide you if you need to redirect or culvert any watercourses that are present within your site. Our comprehensive approach has ensured that we have never had one of our DAs rejected by Rivers Agency.