Lee CFRAMS

Cork Docklands A Case Study

toIrish Planning Institute

21 October 2009

Seamus Coghlan – Senior Engineer, Docklands Directorate – Cork City Council

Presentation

• Planning Background & Rationale• Flooding Issues• Flood Strategy Development Process • Impact of Lee CFRAMS• Conclusions

The N.D.P (2007 – 2013) Vision for the Cork Gateway

• The key challenge identified for Cork during the lifetime of the N.D.P. is 'to significantly accelerate its rate of development and population growth, focussing particularly on the potential of its central area.’

• However the N.D.P. recognised that investment in physical infrastructure to trigger subsequent private investment is necessary. Among the key development and investment priorities identified are roads, water services, port relocation and associated infrastructure to facilitate the regeneration of Cork Docklands and the re-opening of the Cork City-Midleton rail service by 2008.

Cork Gateway

Cork is the second city in the Republic of Ireland and the primary centre of the South West Region;

It is a designated Gateway under the National Spatial Strategy.

Cork Area Strategic Plan: Vision for the Cork Gateway

• A key element of C.A.S.P.'s vision for Cork is that a revitalised City Centre will act as the main economic driver of development in the Region with the redevelopment of the City’s Docklands seen to form a vital role in the City’s renewal.

• CASP Update reinforces Docklandsas the key development for the city facilitating FDI with suitable 3/4G accommodation within the city centre and increased sustainable population growth.

CASP - Metro Area

Docklands Location

• On the River• Proximate to City centre• Adjacent to Transport Hub

(Kent station and Bus Station)

• Sustainable• Critical Mass• Existing services

Vision for the Cork Gateway

Cork Docklands Development Strategy, 2001:

A new urban quarter for Cork that will revitalise the City through high quality contemporary design and a mix of uses

Cork City Council: Development Plan

• Strategy transposed into the 2004 Cork City Development Plan

• Amendment No 11 to Plan in 2007 to incorporate LAP

• “Synchronised”

North and South Docks Local Area Plans

• SDLAP • Public Realm Strategy• Infrastructure Strategy• Strategic Environmental

Assessment• February 2008

• Cork City Council Planning Directorate

• 2005

Cork City Council: Development Plan

• 2009 -2015 Cork City Development Plan

• Precedence over LAP

South (and North) Docks Zonings

• Mixed Use (50/50)• Education and

R&D• District centres • Commercial• 25,000 residents• 27,000 jobs

South Docks Massing

South Docks Massing

Flooding - Historical Background

• Narrow Channel• Scouring effect• Facilitate port traffic

1774

1801

• Docklands is a polder

Historical Background

• City Park

1832

1841

Historical Background• City Park• Fords

1932

1932

Flooding Issues

Docklands - a Polder2-3m

4-5m

Flooding• Raise or Protect ?• Initial Approach – PROTECT – Status Quo• No perceived significant risk – No tidal flooding• 2001 Strategy Document – retain Polder - study• Study undertaken by Dutch Consultants 2003-05 (Tobin

Grontmij Alkyon)– Centred mainly on Drainage issues rather than flooding– Tidal Assessment undertaken – impact on drainage– Storage strategy retained– Raise embankments 5.0mOD – Conservative – Dutch attitude to risk – polder protection – Structural solution

Flooding Concerns• Commencement of SDLAP in 2005• Impact of putting Ground Floor on stilts – Live GF uses required • Role of LA and legal position – risk to LA• Insurability of premises – Risk to Property owners • Tidal and internal SW risk , no fluvial risk• Comparison with City centre

– Flooding in October 2004 – limited impact on Docklands while City severely flooded

– Docklands easily protected ; City difficult• Cost of raising levels - fill• Brownfield regeneration – flexibility & opportunity to raise levels• Impact on strategic utilities (ESB & BGE) – Cost of relocation• Developer & User confidence ( New Orleans syndrome )• Problem Time bound around high tide

Flooding ConcernsImpact of putting Ground Floor on stilts –Live GF uses required

Original GL

Proposed GL

Flooding Workshops• Initial Workshops 2005/6

– discussion and clarity(?)• Stakeholders

– Insurance– Planners– Engineers– Emergency Services

• Insurance Recommendation– Best International Practice– High Quality technical study

Flooding• OPW intervention 2006 – Risk Approach• PPS 25 - UK Approach ( Dec 2005)• Concerns over protection strategy• Pending EU Floods directive• Proposed Lee CFRAM study (pilot) - 2006 start• Catchment based (similar to WFD)• Initial focus on Docklands to determine strategy• Preliminary assessments and modelling

Flooding - CFRAMS• Preliminary CFRAM assessment (2007)• Workshops• Technical preliminary modelling• Relative impact assessment

– no impact on city from raising quay walls as protection– Mainly tidal impact – Little or no river/fluvial impact

• Predicted Future water levels– Including Surge, Sea level rise, Settlement and wave action,

Uncertainty– 5.0 -5.5 mOD provisional pending completion of preliminary

modelling (very conservative) – Joint probability (Surge & high tide & Sea level rise) Analysis

• 4.6mOD

Risk HierarchyOPW Approach

Avoidance of Risk

Reduction of HazardReduction of Risk

Mitigation of Risk

Do not develop; Raise lands above flood level

Protect (on perimeter) : raise quayside / marina

Raise Properties : Min FFL below flood level

Flood resistance & resilience, Forecasting, Emergency access

DRAFT SDLAP Strategy

• June 2007• Mixed Strategy• Primary Perimeter

Protection (Reduce hazard) – 4.6mOD– Permanent protection on

Quay Walls (and elsewhere)– Temporary demountable

Raise ground levels (variable) below Flood levels (Reduce Risk)– 3.5mOD for sensitive

developments (eg hospitals, nursing homes etc) where possible

– To provide satisfactory drainage

• Residual risk mitigation– Flood Resilience– Flood forecasting

Final SDLAP Strategy• February 2008• Perimeter Protection 4.5moD (Hazard reduction)

– Long term protection (Sae level rise)– Adaptable

• Raise ground levels ABOVE Flood levels (Reduce Risk)– MIN FFL 3.5mOD for ALL developments – Minimise residual risk to life

• Review on completion of CFRAMS

Flood Management Strategy

FFL 3.5mOD

Perimeter protection 4.5mOD

Flood Resilience

Temporary demountables

Perimeter Protection & Public Realm

Lee CFRAM Modelling

• Halcrow Consultants Report– Tidal Analysis– Defence Asset assessment– Hydrology– River Hydraulics 1D/2D

modelling– Options Assessment

methodology/process (3 Stages)– Multi criteria analysis of

proposals– SEA

• Outputs– Flood RISK Management Strategy– Complex – Tidal & Fluvial Interface– Iniscarra dam influence– Risk Maps

» Extents » Depth» Flow

• Significant impacts on Docklands & City

Lee CFRAM

• 2009 – Final Draft Report• Review of Docklands Flood Strategy• Future water level prediction

– reduction 4.35mOD (MLFS –SLR(50), 1in 20 JP tide)• No Change in Strategy for time being – LAP

Review• Perimeter Protection 4.5mOD (Adaptable) long

term• Min FFL 3.5mOD

Storm Drainage• Docklands is a Polder• Previously storage proposed – Tobin Gronmij• Raise levels - 3.5mOD • Drain directly to river• Overflow to Lower Level• SUDS

Planning FRM Guidelines & FRM Draft Docklands report

• Good practice in decision making was achieved on the FRM – Staged assessment– No increase in flood risk

elsewhere– Measures minimise FR to

people, property & environment

– Residual risks are managed

• report Commissioned by OPW

• Draft • Report synopsised above• Justification achieved for

a flood prone area• Surface water addressed

Docklands Conclusions • Polder not a flood plain• Tidally dominated• Risks are reduced due to

narrow timeframe of high tide, no impacts on city through perimeter protection

• Importance and regeneration and sustainability of docklands key justification for development

• Changed original strategy to manage the residual risks

• Utilised Risk approach and hierarchy to FRM -mixed strategy

• Phased implementation • Circumstances particular

to Docklands regeneration

• Approach not applicable in all situations

• Each situation needs to be assessed on its merits and risks.

General Conclusions

• Make a start now ! Long process - Management Agenda

• Stakeholder Workshops important – involve all key people/organisations

• Understand Risk concepts & Risk hierarchy

• Risk: Frequency and Impact of consequences

• Planning & Flood risk Guidelines and methodology important

• CFRAMS key tool in decision making – quantifies impacts – accuracy?

• Challenge CFRAMS methodologies and modelling outputs

• Apply local knowledge and previous experience

• Model – very Sophisticated –possible unrealistic expectations

Lee CFRAMS

Cork Docklands A Case Study

toIrish Planning Institute

21 October 2009

Seamus Coghlan – Senior Engineer, Docklands Directorate – Cork City Council