Flood Risk Assessment Glasgow

Flood Risk Assessment Services in Glasgow

Glasgow’s position on the River Clyde, combined with its extensive urban drainage infrastructure and numerous tributaries, creates one of Scotland’s most complex flood risk environments. The city has invested heavily in flood prevention in recent decades, but significant residual risk remains, and the planning system requires rigorous assessment for all development proposals in or near flood risk areas.

Aegaea delivers specialist flood risk assessment, hydraulic modelling, and drainage consultancy services across Glasgow. Our team has detailed knowledge of the city’s watercourses, SEPA flood mapping, Glasgow City Council’s planning requirements, and the Metropolitan Glasgow Strategic Drainage Partnership (MGSDP) framework that shapes surface water management across the conurbation.

Glasgow’s Flood Risk Landscape

The River Clyde

The River Clyde is the defining geographical feature of Glasgow, flowing through the city centre from east to west before widening into the Firth of Clyde. The tidal limit of the Clyde lies at the weir near Glasgow Green, meaning that the city centre and areas downstream are influenced by both fluvial flows and tidal conditions.

Historic flooding along the Clyde has affected Glasgow repeatedly. The January 2014 tidal surge event caused flooding along the lower Clyde, and fluvial flooding has historically affected areas including Glasgow Green, Dalmarnock, and Bridgeton. The Clyde’s extensive quay walls and embankments provide a degree of protection to the city centre, but these are not classified as formal flood defences and their condition varies.

The Clyde Gateway regeneration area, encompassing Dalmarnock, Bridgeton, and parts of South Lanarkshire, represents one of Scotland’s largest regeneration initiatives. Flood risk from the Clyde and its tributaries is a key constraint for development in this corridor, and site-specific FRAs must address both current and climate change flood risk over the development design life.

Development along the Clyde corridor, including the major regeneration sites at Pacific Quay, the International Financial Services District, and Queen’s Quay at Clydebank, requires careful assessment of tidal and fluvial interaction, finished floor level setting, and resilience to extreme events. The tidal influence means that predicted flood levels must account for combined river flow and tidal scenarios, including the potential for climate change to increase both peak flows and sea levels.

White Cart Water

The White Cart Water is Glasgow’s second most significant watercourse for flood risk, flowing northward through Cathcart, Battlefield, Langside, and Shawlands before joining the Clyde near Cardonald. The catchment extends south into East Renfrewshire, and the river has a history of severe flooding in its lower reaches.

The White Cart Water Flood Prevention Scheme was completed in 2012 at a cost of approximately 52 million pounds. The scheme provides protection against a 1 in 200 year event for around 1,700 properties using a combination of raised walls, embankments, floodplain storage, and upstream flow attenuation. Dams at Balgray and Waulkmill reservoirs were enhanced to provide additional flood storage capacity.

Despite this investment, development within and adjacent to the White Cart corridor still requires flood risk assessment. Properties within the defended area face residual risk from events exceeding the design standard, and the consequences of defence overtopping or failure must be assessed. Sites upstream of the scheme, including areas in Busby and Clarkston, remain at risk from undefended flooding.

River Kelvin

The River Kelvin flows through the west end of Glasgow, passing through Maryhill, the Botanic Gardens, Kelvingrove Park, and Partick before joining the Clyde at Yorkhill. The Kelvin corridor includes significant development pressure, particularly around the former Maryhill Barracks site, Firhill, and the West End conservation area.

The Kelvin is a relatively flashy river, responding quickly to rainfall events, and historic flooding has affected properties in Maryhill, Kelvindale, and along Great Western Road. SEPA flood maps show significant fluvial flood risk along the Kelvin corridor, and development proposals in these areas require detailed hydraulic assessment.

The River Kelvin Flood Prevention Scheme has been under development by Glasgow City Council, with feasibility studies and options appraisal work ongoing. Until formal defences are in place, development along the Kelvin must be assessed against undefended flood risk levels.

Surface Water and Sewer Flooding

Surface water flooding is arguably Glasgow’s greatest flood challenge. The city’s extensive impermeable surfaces, steep topography in some areas, and ageing combined sewer network create significant vulnerability to intense rainfall events. The July 2002 storm caused widespread surface water and sewer flooding across the city, and similar events have occurred subsequently.

SEPA’s surface water flood maps show extensive areas at risk across Glasgow, particularly in low-lying areas such as the Clyde floodplain, Shawlands, Tradeston, and Springburn. The combined sewer system, which carries both foul and surface water, is particularly vulnerable to surcharging during intense rainfall, leading to flooding from manholes and combined sewer overflows.

The Metropolitan Glasgow Strategic Drainage Partnership (MGSDP) was established to address Glasgow’s strategic drainage challenges. The partnership brings together Glasgow City Council, Scottish Water, SEPA, Scottish Enterprise, and neighbouring authorities to coordinate investment in drainage infrastructure and promote surface water management at a catchment scale. The MGSDP Surface Water Management Plan identifies critical drainage areas and sets priorities for investment.

The Scottish Regulatory Framework for Glasgow

SEPA’s Role

SEPA is the statutory body responsible for flood risk management strategy in Scotland under the Flood Risk Management (Scotland) Act 2009. For Glasgow developments, SEPA provides flood risk information through its online flood maps, responds to planning consultations, and publishes guidance on flood risk assessment standards.

SEPA’s consultation responses on Glasgow planning applications assess whether submitted FRAs adequately address all relevant flood sources, demonstrate that development will not increase flood risk elsewhere, and propose appropriate mitigation. Where SEPA objects to a planning application on flood risk grounds, Glasgow City Council will typically refuse the application unless the objection can be satisfactorily resolved.

SEPA’s Technical Flood Risk Guidance for Stakeholders sets out the expected approach to flood risk assessment in Scotland. Key requirements include assessment of the 1 in 200 year flood event (0.5% annual probability) as the design standard, consideration of all relevant flood sources, application of appropriate climate change allowances, and demonstration that the development is safe over its design life.

NPF4 and Glasgow’s Local Development Plan

NPF4 Policy 22 provides the national planning policy framework for flood risk in Scotland. Glasgow City Council’s City Development Plan and associated supplementary guidance provide local planning policy context, including policies on flood risk, surface water management, green infrastructure, and SuDS.

Glasgow’s supplementary guidance on flood risk and drainage references the MGSDP framework and requires developers to demonstrate how their proposals contribute to the strategic management of surface water across the conurbation. This goes beyond individual site-level SuDS to consider catchment-scale impacts and opportunities for blue-green infrastructure.

The council’s Strategic Flood Risk Assessment informs the spatial strategy of the local plan, identifying areas where flood risk constrains development and areas where investment in flood defence or drainage infrastructure may unlock development potential.

Scottish Water Requirements

Scottish Water’s requirements for new connections have a significant impact on drainage design in Glasgow. Sewers for Scotland 4th Edition sets out the technical standards for new drainage infrastructure, and Scottish Water will not accept new surface water connections to the combined sewer network. This requirement drives the adoption of SuDS and, where feasible, discharge to watercourse or ground.

In Glasgow’s urban context, where ground conditions may limit infiltration and watercourse connections may not be available, meeting Scottish Water’s requirements can be challenging. Creative SuDS design, including green roofs, permeable paving, rainwater harvesting, and detention basins, is often necessary to manage surface water without reliance on the combined sewer.

Key Development Areas in Glasgow

Clyde Gateway and East End Regeneration

The Clyde Gateway area, including Dalmarnock, Bridgeton, and the former Commonwealth Games athletes’ village site, is one of Glasgow’s primary regeneration zones. Flood risk from the Clyde and Camlachie Burn is a key constraint, and the area’s industrial legacy means that contaminated land assessment is often required alongside flood risk work.

Pacific Quay and the Riverside

The south bank of the Clyde at Pacific Quay, including the area around the BBC Scotland headquarters and the Science Centre, sits within the Clyde’s tidal floodplain. Development in this area requires assessment of combined tidal and fluvial flood risk, with finished floor levels set above the predicted 1 in 200 year combined flood level plus climate change and freeboard allowances.

Maryhill and Canal Corridor

The Maryhill area, including the former Maryhill Barracks site and land adjacent to the Forth and Clyde Canal, is a focus for residential development. The River Kelvin and the canal both present flood risk considerations, and the interaction between the two water bodies requires careful assessment. Surface water management in this area must also account for runoff from the steep surrounding topography.

City Centre and Merchant City

Change-of-use and intensification proposals in Glasgow’s city centre must address surface water management in a highly constrained urban environment. The combined sewer network beneath the city centre has limited residual capacity, and SuDS solutions must be integrated into building design. Basement developments and below-ground uses require specific assessment of groundwater and sewer surcharge risk.

Sighthill Regeneration

The Sighthill Transformational Regeneration Area, one of Glasgow’s most ambitious housing-led regeneration projects, required extensive flood risk assessment and drainage design to address surface water risk and ensure that the new urban form does not increase flood risk in adjacent areas. This project exemplifies the scale of flood risk and drainage work required for major Glasgow regeneration schemes.

Aegaea’s Glasgow Services

Aegaea provides comprehensive flood risk and drainage services across Glasgow, including desktop and detailed flood risk assessments for planning applications, 1D-2D hydraulic modelling of the Clyde, White Cart Water, Kelvin, and smaller watercourses, surface water drainage strategies and SuDS design to Scottish Water and MGSDP standards, SEPA pre-application consultation and objection resolution, flood risk input to masterplanning and development framework preparation, and expert witness services for planning appeals and inquiries.

Our understanding of Glasgow’s specific flood risk context, regulatory framework, and development challenges means we can deliver robust, efficient assessments that meet the requirements of SEPA, Glasgow City Council, and Scottish Water. We work with developers, housing associations, architects, and planning consultants across the city to support successful planning outcomes.

Contact Aegaea

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