Bandon Flood Early Warning System

Bandon Flood Early Warning System

Dave Clarke

Cork County Council

County Engineer’s Department

Water Services Investment Programme Project Office

ContentsContents

Overview of Flooding in Bandon

What can we do to Manage Flood Risk in Bandon?

Flood Early Warning Systems

Bandon Flood Early Warning System– Benefits– Design – Communication– Operation & Maintenance

Questions

Overview of Flooding in BandonOverview of Flooding in BandonWhat are the sources of flooding in Bandon?• Pluvial (direct rainfall) √• Fluvial (river) √• Tidal (sea) X

What causes flooding in Bandon?• Pluvial flooding occurs when rainfall intensity /amounts

exceed the capacity of existing storm water or combined sewerage pipes.

• Fluvial flooding occurs the river channel cannot pass high flood flows. This is largely as a consequence of historic raising and building on the flood plain combined with confining the river channel – from the weir to the WWTP..

Overview of Flooding in Bandon 10 Largest Flood Events Since 1960

Overview of Flooding in Bandon 10 Largest Flood Events Since 1960

Date * Peak Time * Peak Staff Reading (m) *

Gauge Level (mOD Malin)

Flood Warning

Code

13 December 1964 14.15 2.850 14.043 YELLOW

23 October 1975 12.00 3.568 14.761 ORANGE

07 December 1978 6.00 2.746 13.939 YELLOW

21 February 1982 14.45 2.971 14.148 ORANGE

06 August 1986 15.30 3.1008 14.278 ORANGE

22 October 1988 22.45 3.233 14.410 ORANGE

03 February 2004 20.45 2.673 13.850 YELLOW

08 January 2005 11.30 2.877 14.054 ORANGE

03 December 2006 17.00 2.674 13.851 YELLOW

19 November 2009 21.30-21.45 4.216 15.393 RED

Flooding is occurring every 8 years on average.

The ’75 event was approaching a RED event.

2009 event approximately 1 in 300.

Consequences of FloodingConsequences of Flooding

Consequences of FloodingConsequences of Flooding

Consequences of FloodingConsequences of Flooding

Managing Flood Risk in BandonManaging Flood Risk in Bandon

Risk = Probability of Event Occurring x Impact of Event

How can we address and reduce Bandon flood risks?

• Pluvial flood risk will be addressed by installing new and upsized pipes as part of the Bandon Sewerage Scheme

• Fluvial flood risk will be addressed through the implementation of the Bandon Flood Relief Scheme

• Fluvial flood risk will be managed through the implementation of the Bandon FEWS

Bandon FEWS will not reduce the probability of a flood event occurring – it will reduce the impact by giving people time to safeguard property and move to a safe location. In this way the risk is reduced.

Flood Early Warning Systems in context

Flood Early Warning Systems in context

Flood early warning systems are operated in many countries including our neighbours England, Scotland and Wales. France Sweden and the USA also have national viable flood forecast and early warnings systems

In Ireland only a small number of locations currently have the benefit from fluvial flood early warning systems – Mallow, Fermoy and Clonmel.

Bandon Flood Early Warning System - Benefits

Bandon Flood Early Warning System - Benefits

The Bandon Flood Early Warning System allows for Cork County Council to give prior warning that there is a risk of an imminent flood event in Bandon Town.

This enables the local authorities, its emergency partners & people in the effected areas of town, to mobilise their flood action plans and thereby reduce damage to property & contents.

The system will be capable of raising a flood alert with approximately 5 hours warning time.

Bandon Flood Early Warning System Overview of Design

Bandon Flood Early Warning System Overview of Design

• Level to Level relationship has been established between upstream and downstream gauges

• Bealaboy automatic gauge – records since 1991

• Antecedent Conditions – catchment wetness

• Automatic Rainfall Gauge being installed

• Knowing current upstream level and antecedent conditions – can predict downstream levels about 5 hours in advance

Bandon Flood Early Warning System – Components & Communications

Bandon Flood Early Warning System – Components & CommunicationsSystem consists of:• 3 level gauges and 1 rainfall gauge• Telemetry – every 15 minutes• Computer server – data and program• Computer server hosting website

• Operator will automatically receive an alert from the system.

• Operator ‘calls’ a flood event and authorises a flood alert

• System will automatically raise an alert in the event of a non response from the Operator

Flood Warning Codes Flood Warning Codes

Flood Warning Code

Flooding Type

GreenAll Clear, No

Flooding

Yellow Minor Flooding

Orange Serious Flooding

RedSevere/Extreme

Flooding

A set of 4 easy recognisable flood warning codes are issued by the Bandon Flood Early Warning System (FEWS).

Flood Warning Codes Flood Warning Codes

GREEN STATUS – ALL CLEAR, NO FLOODING - No risk of flooding.

After a flood event has peaked & the water levels have receded a GREEN STATUS – All Clear will be issued. The flood warning is no longer in place. Please note that after a serious flood event it is important to seek appropriate advice & check it is safe to return to your property.

Flood Warning Alert SMS message content:

“Bandon Flood Warning Code. GREEN STATUS, ALL CLEAR. 00:00hrs dd/mm/yyyy.”

0

Flood Warning CodesFlood Warning Codes

YELLOW ALERT - MINOR FLOODING - Risk of flooding to walkway on northern bank

Local impacts• Initially riverside walkway on northern bank of river between Bandon Bridge &

footbridge at risk of moderate flooding (Public Registered users will not be issued a text alert)

• Higher flood water levels submerge all of walkway – walkway dangerous to access. Playground at risk of flooding. (Public Registered users will be issued a text alert.)

We expect about 3 ‘high’ yellows flood events per year

What to do• Tune into local radio stations for flood / weather updates.• Check www.bandonfloodwarning.ie for updates.• Be alert of the water levels near you.• Be ready to act on your flood plan, if the flood alert is raised to an Orange or Red

alert.• Avoid open riverbank areas.

Flood Warning Alert SMS message content“Bandon Flood Warning Code. YELLOW ALERT. 00:00hrs dd/mm/yyyy.”

Flood Warning CodesFlood Warning Codes

ORANGE ALERT – SERIOUS FLOODING - Risk of flooding in streets. Risk of flooding of low lying property. Action required!

Local impacts - Streets & property in the lowest parts of town & the playground at risk of flooding. Flooding is likely to commence in the vicinity of Hickeys Corner, Brady’s Corner, Bank Place. Playground flooded.

Flood events similar to October 1975, February 1982, August 1986, October 1988 & January 2005.

What to do• Tune into local radio stations for flood / weather updates.• Check www.bandonfloodwarning.ie for updates.• Act on your flood plan.• Move valuables, cars, documentation, pets and other items to safety• Put flood protection equipment in place.• Turn off electricity/ gas/ water if applicable & safe to do so.• Evacuation of property may be required.• Protect yourself, family & assist others / Check the safety of elderly in flood zone.

Flood Warning Alert SMS message content“Bandon Flood Warning Code. ORANGE ALERT. 00:00hrs dd/mm/yyyy.”

Bandon Flood Early Warning SystemFlood Warning Codes

Bandon Flood Early Warning SystemFlood Warning Codes

RED ALERT – SEVERE / EXTREME FLOODING - severe flood event expected. Extensive areas of town at flood risk. Risk to property & life.

Flood event similar to November 2009 and slightly larger than the 1975 event.

Local impacts• Significant flooding of streets & properties in town centre area & Bank Place.• Glasslinn Road (Cork Road) may become impassable. • Quay walls & existing flood defences may be overtopped.• Electricity & telecommunication services may be interrupted. • Transport services may be disrupted.

What to do• Tune into local radio stations for flood / weather updates.• Check www.bandonfloodwarning.ie for updates.• Act on your flood plan. Put flood protection equipment in place.• Move valuables, cars, documentation, pets and other items to safety.• Turn off electricity/ gas/ water if applicable & safe to do so.• Protect yourself, family & assist others / Check the safety of elderly in flood zone. • Prepare for evacuation, assemble essential items e.g. medication, clothing, etc.• Evacuate in advance of flood waters if safe to do so.• Cooperate with emergency services.

Flood Warning Alert SMS message content“Bandon Flood Warning Code. RED ALERT. 00:00hrs dd/mm/yyyy.”

Bandon Flood Early Warning System – Operation & Maintenance

Bandon Flood Early Warning System – Operation & Maintenance

The river gauges and telemetry system will continue to be owned, operated and maintained by the OPW.

The automatic rainfall gauge will be owned, operated and maintained by CCC.

The computer system, server, website etc. will be operated for the initial 12 month period by RPS Consulting Engineers on behalf of CCC.

The ‘Operator’ for raising flood alerts will be Council Staff

Timetable for ImplementationTimetable for Implementation• www.bandonfloodwarning.ie has been registered to CCC.

• The website will be up in approx 2 weeks. Initially the website will be accessible by password only until the content etc. has been 'signed off'.

• The contract to upgrade / reprogramme the OPW telemetry system to communicate with the Flood Early Warning System (FEWS) server has been awarded to OTT - this is scheduled to be completed by the end of the month.

• The text alert communication contract has been awarded to Vodafone.

• Assuming all the above pieces come together and no unforeseen technology snags the FEWS will be at operational status for internal use by the end of the month.

• Following signing off on the web content, the system will be publicly accessible and the public can start pre-registering to receive text flood alerts once the system has been successfully trialled.

19th November 2009 Event – How Would Bandon Flood Early Warning Have Worked?

19th November 2009 Event – How Would Bandon Flood Early Warning Have Worked?• ‘High’ Yellow alert at 1:00 am• Orange alert at 7:00 am • Red alert at 11:15 am

• Flooding of streets commenced at approximately 1:00 pm.

• Would have known at 3:45 pm that upstream flood waters had peaked and could predict that the flood would not peak in Bandon until around 9:00 to 10:00 pm

SummarySummary

Bandon Flood Early Warning System will:• Provide automated river level monitoring and approx. 5

hours warning of an imminent flood event• Estimate the scale of the flood event – yellow – orange –

red • Provide, through the Website –

www.bandonfloodwarning.ie – real time information on river levels and flood alerts, advice on flood action plans, information on historical flooding and on ongoing and proposed flood relief works.

• Provide the facility for members of the public to register for automatic text flood alerts.

AcknowledgementsAcknowledgements

• OPW and their staff for their time and assistance, their level records and use of their gauges and finally their financial support!

• Professor Ger Kiely of UCC

• RPS Consulting Engineers

• CCC & BTC Staff

Questions?Questions?