Flood Risk Assessments

Flood Risk Assessments (FRA) and/or Sustainable Drainage designs (SuDs) are now required for all sites of greater than 1ha, or in other sensitive locations. At Peak Associates we’ll taylor a design to your sites’ individual needs. A FRA reviews the risk of flooding posed to the site from existing flood risks such as rivers, canals, and reservoirs. The report also covers how this risk will affect the proposed development and make recommendations as to how this risk can be mitigated within the proposed design. The report assesses the risk based on data provided by the Environment Agency which categorises flood risk into three separate zones (Flood Zones 1, 2 and 3) depending on the level of perceived risk.

An FRA is required for all planning applications for the following developments:

  • In Flood Zones 2 or 3 areas (areas at a 1:1,000 and 1:100 year risk of flooding)
  • In Flood Zone 1 if the site area is greater than 10,000 square metres (1ha)
  • You may also be required to submit an assessment if the site is located next to a local non-mains river watercourse or a Critical Drainage Area (CDA)

Flood Risk Assessments (cont’d)

Peak Associates staff have a wide range of experience in the production of detailed, site specific flood risk assessments for all types of developments in accordance with the requirements of the National Planning Policy Framework, which has partly replaced the old PPS25. Our staff can also provide recommendations and advice regarding mitigation works that may be required as a result of this assessment.

All risk assessments completed by Peak Associates are fully tailored to the unique requirements of each site and can be completed for all sizes of developments from small-scale residential developments to commercial expansions or new large commercial properties. Peak Associates have completed these types of assessments for sites across the country including Cheshire, Manchester, Lancashire, and Cumbria.

Peak also has the facilities to complete Sustainable Drainage Schemes (SuDS) for sites to ensure that the proposed development does not increase the flood risk to the local environment. Many of our clients have found that our joint FRA and Conceptual SuDS reports have provided a cost effective means of satisfying the Local Planning Authority (LPA) concerns regarding flood risk in a single one stop report.

Full drainage studies can also be provided for existing sites where expansion is being proposed to ensure that the drainage system in place is suitable and will be appropriate for the new development. Our staff members have a range of expertise in this area and can provide detailed advice on works which may be required and with the further progression of the planning application.

Summary of benefits:

  • A site specific report completed to National Planning Policy Framework guidance to get your scheme approved.
  • Recommendations on adaptations to proposed designs by experienced professionals.
  • Potential to incorporate SuDS design in report as a more cost effective approach.

Residential development, Stockport

A FRA was requested by the LPA for a site that whilst situated in Flood Zone 1, and therefore at the lowest risk of flooding.

The assessment was triggered as the site had a brook running through it. The FRA focused on the risk posed to the proposed development from flooding from the brook including run off scenarios for the brook upstream of the site and the culvert blockage on site.

The report included recommendations such as finished floor levels, work required on a small culverted section of the brook which would be a throttle point in the event of heavy rainfall, and the need for a Sustainable Drainage Scheme (SuDS) to be incorporated into the design to reduce the impact of the development on flooding to the local area downstream.

Fish Farm, Cheshire

A Flood Risk Assessment (FRA) was completed for a site situated next to the River Dee in Cheshire.

A commercial fish farm, which due to its nature was next to the river, required an additional agricultural building and a FRA was completed for the site as it was located within Flood Zone 3 and therefore had the greatest risk of flooding.

The FRA summarised the risks posed to the development and included numerous recommendations on safety features to be included within the design in order to ensure that the proposed development would be safe including a recommended finished floor level, refuge area with 24 hours of provisions, flood resilient building materials and a warning system to allow safe egress to dry land should they ever get cut off in the flood.