Flood Risk Assessment Aberdeen

Flood Risk Assessment Services in Aberdeen

Aberdeen occupies a distinctive position at the mouths of two major rivers, the Dee and the Don, on Scotland’s North Sea coast. This geography creates a complex flood risk environment where fluvial, coastal, and surface water risks interact. The city’s ongoing expansion, driven by the energy sector and significant regeneration initiatives, means that flood risk assessment is a routine requirement for development proposals across the city.

Aegaea provides specialist flood risk assessment, hydraulic modelling, and drainage consultancy services throughout Aberdeen and Aberdeenshire. Our team has direct experience of SEPA’s requirements, Aberdeen City Council’s planning policies, and the specific hydrological characteristics of the Dee and Don catchments.

Aberdeen’s Flood Risk Environment

The River Dee

The River Dee is one of Scotland’s premier salmon rivers, flowing approximately 140 kilometres from the Cairngorm Mountains to the North Sea at Aberdeen. The lower Dee passes through the southern suburbs of Aberdeen, including Peterculter, Milltimber, Cults, and Torry, before reaching the harbour and estuary.

The Dee has a relatively large catchment area of approximately 2,100 square kilometres, and its flow regime is influenced by snowmelt from the Cairngorms, which can contribute to significant spring flood events. The December 2015 and January 2016 floods, associated with Storm Frank, caused substantial flooding along the Deeside corridor, affecting properties in Ballater, Aboyne, and areas upstream of Aberdeen. Within the city, the lower Dee’s flood risk is moderated by the broad floodplain and the tidal influence at the river mouth, but areas adjacent to the river remain at risk.

The River Dee floodplain through Aberdeen includes significant development, particularly in the Garthdee area around Robert Gordon University, and along the riverside at Duthie Park and Torry. Development proposals in these areas require detailed FRA addressing fluvial flood risk under both current and climate change conditions. The interaction between river flows and tidal conditions at the Dee mouth means that combined probability analysis may be required for sites near the estuary.

The River Don

The River Don flows through the northern part of Aberdeen, passing through Dyce, Grandholm, and the Bridge of Don before discharging to the sea at Donmouth. The Don catchment, covering approximately 1,300 square kilometres, includes significant urbanised areas around Dyce and the airport, as well as agricultural land upstream.

The Don has a well-documented history of flooding. The November 2002 floods caused extensive damage along the Don valley, affecting properties in Inverurie, Kintore, and areas within Aberdeen. The December 2015 Storm Frank event also caused significant flooding in the Don catchment. SEPA flood maps identify extensive areas at risk along the Don corridor within Aberdeen, including land around the Bridge of Don, Danestone, and Grandholm.

The Grandholm area, a significant brownfield regeneration opportunity at the confluence of the Don and its tributary the Bucks Burn, exemplifies the flood risk challenges facing Aberdeen developers. The site’s position within the Don floodplain means that any development proposal must demonstrate compliance with NPF4 Policy 22 and satisfy SEPA’s requirements regarding flood risk mitigation, land raising, and finished floor levels.

Coastal Flood Risk

Aberdeen’s North Sea coastline extends from Cove Bay in the south to Donmouth in the north, encompassing the harbour, beach area, and Footdee (Fittie) fishing village. Coastal flood risk from storm surges, wave action, and wave overtopping is a significant consideration for development along this frontline.

The Aberdeen Harbour expansion at Nigg Bay, one of the largest marine construction projects in the UK in recent years, required comprehensive coastal flood risk assessment. The new harbour infrastructure provides some protection to adjacent areas, but development on land behind the harbour must still address residual coastal risk.

The Aberdeen Beach area, including the Esplanade and adjacent leisure and residential properties, is exposed to wave overtopping during storm events. The December 2012 storm surge event caused flooding and damage along the beachfront, highlighting the vulnerability of this area. Regeneration proposals for the beach area, including the city centre masterplan, must incorporate coastal flood risk assessment and appropriate mitigation.

Sea level rise projections from UKCP18 indicate that coastal flood risk in Aberdeen will increase significantly over the coming decades. Development proposals must account for predicted sea level rise over the development’s design life, which for residential development is typically assessed over a 100-year horizon.

Surface Water Flooding

Surface water flooding affects numerous locations across Aberdeen. The city’s topography includes relatively steep ground draining to the Dee and Don valleys, creating natural surface water flow paths. Combined with the urban environment’s impermeable surfaces and ageing drainage infrastructure, this creates vulnerability to intense rainfall events.

SEPA’s surface water flood maps identify areas at risk across Aberdeen, including low-lying areas in Torry, Kittybrewster, Northfield, and parts of the city centre. Scottish Water’s sewer flood records identify additional locations where the drainage network has insufficient capacity to manage extreme rainfall.

The Denburn, a watercourse that flows through the heart of Aberdeen largely in culvert beneath Union Terrace and the railway, presents a particular challenge. The culverted watercourse has limited capacity, and exceedance flows during extreme events can cause surface water flooding in the city centre. Development proposals in this area must assess the risk of surcharging from the culverted Denburn.

Scottish Regulatory Framework

The Flood Risk Management (Scotland) Act 2009

Aberdeen’s flood risk management operates under the Flood Risk Management (Scotland) Act 2009, which established SEPA as the lead authority for strategic flood risk management. Aberdeen City Council, as a “responsible authority,” is responsible for local flood risk management, including the assessment of flood risk from smaller watercourses and surface water.

Aberdeen falls within the North East Local Flood Risk Management Plan area, which was prepared under the 2009 Act. The plan identifies Potentially Vulnerable Areas (PVAs) where flood risk is considered most significant and sets out objectives and actions for managing that risk. Development proposals within PVAs are subject to particular scrutiny from SEPA and the council.

NPF4 Policy 22

National Planning Framework 4 Policy 22 applies to all development in Aberdeen. The policy requires that development proposals avoid flood risk areas where possible, and where development in flood risk areas is proposed, it must demonstrate that it will not increase flood risk elsewhere and that appropriate mitigation is in place.

For Aberdeen developments, the key NPF4 requirements include assessment of the 1 in 200 year flood event as the design standard, consideration of all flood sources including fluvial, coastal, surface water, and groundwater, application of climate change allowances over the development’s design life, and demonstration that the development is safe for its intended use.

Aberdeen Local Development Plan

Aberdeen City Council’s Local Development Plan contains specific policies on flood risk, drainage, and water management. The plan directs development away from flood risk areas and requires site-specific FRAs for proposals in or near areas identified on SEPA flood maps. The council’s supplementary guidance provides detailed requirements for FRA content, SuDS design, and drainage strategy preparation.

Aberdeen’s Strategic Flood Risk Assessment informs the plan’s spatial strategy, identifying areas where flood risk is a material constraint and areas where development may be appropriate subject to appropriate FRA and mitigation.

Key Development Areas

Aberdeen Harbour and Torry

The harbour area and Torry waterfront face combined fluvial, tidal, and coastal flood risk from the Dee estuary and the North Sea. The South Harbour development and ongoing regeneration of the Torry waterfront require detailed assessment of these combined risks, including the potential for coincident tidal and fluvial events.

Dyce and Airport Corridor

The Dyce area, adjacent to Aberdeen International Airport, lies within the Don floodplain and has experienced historic flooding. The energy sector’s presence in this area drives significant commercial and industrial development demand, and flood risk from the Don and surface water is a recurring planning consideration. The Aberdeen Western Peripheral Route has altered some surface water flow paths in this area, and post-construction flood risk assessment may be required.

Countesswells and Greenferns

The major housing allocations at Countesswells and Greenferns in western Aberdeen involve significant greenfield development. While these sites are generally at lower fluvial risk, surface water management and drainage strategy are critical considerations. The developments must demonstrate that runoff from the new urban areas will not increase flood risk downstream in the Dee and Culter Burn catchments.

Union Street and City Centre

City centre development and change-of-use applications must address surface water management in Aberdeen’s constrained urban fabric. The culverted Denburn, limited space for SuDS, and the granite-built character of the conservation area create specific challenges for flood risk mitigation and drainage design.

Aegaea’s Aberdeen Services

Aegaea provides comprehensive flood risk and drainage services across Aberdeen, including desktop and detailed flood risk assessments for planning applications, hydraulic modelling of the Dee, Don, and smaller watercourses, coastal flood risk assessment including wave overtopping analysis, surface water drainage strategies and SuDS design to Sewers for Scotland standards, SEPA pre-application consultation and objection resolution, and contaminated land assessment for brownfield sites where flood risk and contamination interact.

Our understanding of Aberdeen’s specific flood risk context, the SEPA regulatory framework, and Aberdeen City Council’s planning requirements means we deliver efficient, targeted assessments that support successful planning outcomes. We work with developers, energy companies, architects, and planning consultants across the city and wider Aberdeenshire.

Contact Aegaea

If you are planning a development in Aberdeen and need a flood risk assessment, drainage strategy, or SuDS design, contact Aegaea for a no-obligation discussion. Our team can advise on the likely scope of work and help you navigate Aberdeen’s flood risk and drainage requirements from the earliest project stages.