dam break assessment.pdf

By Ir. Dr. Lim Foo Hoat

Angkasa Consulting Services Sdn Bhd

“Dam Break Risk Assessment”12th July 2012

Putrajaya International Convention Centre

SEMINAR PENGURUSAN RISIKO DALAM PENGURUSAN PROJEK

Air Itu Anugerah Tuhan

Dam Break Risk AssessmentDam Break Risk Assessment

�� Part 1 Part 1 –– Dam Break Analysis and ModelingDam Break Analysis and Modeling

�� Part 2 Part 2 –– Social Impact Study Social Impact Study

�� Part 3 Emergency Response PlanPart 3 Emergency Response Plan

PART 1PART 1

Dam Break Analysis and ModelingDam Break Analysis and Modeling

Dam Break AnalysisDam Break Analysis

�� To assess extent of damage and analyze To assess extent of damage and analyze hydraulic characteristics (velocity, depth, hydraulic characteristics (velocity, depth, flood wave arrival time) due to failure of flood wave arrival time) due to failure of dam embankmentdam embankment

�� Part of Emergency Response Plan Part of Emergency Response Plan Requirement For Dam Operators Requirement For Dam Operators

�� To prepare an ERP for planning and To prepare an ERP for planning and remedial actions if dam break is inevitable.remedial actions if dam break is inevitable.

Dam Break AnalysisDam Break Analysis

�� Socio economic impact resulting from Socio economic impact resulting from occurrence of dam breakoccurrence of dam break

�� Dam break modeling results provide Dam break modeling results provide emergency information, emergency emergency information, emergency operation, warning for residents, flood operation, warning for residents, flood warning warning

Example of Dam FailuresExample of Dam Failures

(Teton Dam)(Teton Dam)

((Dam failure near Torgou, Germany))

Sequence of Dam Sequence of Dam FaliureFaliure (Teton Dam)(Teton Dam)

Methodology of Dam Break Methodology of Dam Break

AnalysisAnalysis�� Numerical Model Numerical Model

-- 1D, one dimensional model (1D model) 1D, one dimensional model (1D model) ––MIKE 11, HECRAS, FLDWAV, MIKE 11, HECRAS, FLDWAV,

-- 1/2D, one dimensional river and two 1/2D, one dimensional river and two dimensional flood plain dimensional flood plain –– MIKE FLOOD, XP MIKE FLOOD, XP SWMM 2DSWMM 2D

-- 2D flow river and flood plain 2D flow river and flood plain

�� Parameter / Data input are ManningParameter / Data input are Manning’’s n and s n and crosscross--sectional data extracted from the scale of sectional data extracted from the scale of 1: 50 000 topographic maps, and elevation 1: 50 000 topographic maps, and elevation levels (horizontal data) extrapolated from levels (horizontal data) extrapolated from Google Earth.Google Earth.


AnalysisAnalysis�� Choice of Numerical ModelChoice of Numerical Model

-- 1D, one dimensional model (1D model) 1D, one dimensional model (1D model) ––MIKE 11, HECRAS, DAMBRK, FLDWAV, MIKE 11, HECRAS, DAMBRK, FLDWAV,

-- 1/2D, one dimensional river and two 1/2D, one dimensional river and two dimensional flood plain dimensional flood plain –– MIKE FLOOD, XP MIKE FLOOD, XP SWMM 2D, INFOWORK 2D, SOBEK, SWMM 2D, INFOWORK 2D, SOBEK, ISIS2DISIS2D

-- 2D flow river and flood plain, MIKE FLOOD, 2D flow river and flood plain, MIKE FLOOD, TUFLOW, SRHTUFLOW, SRH--2D, Surface Modeling 2D, Surface Modeling System SMSSystem SMS

Model Selection Based on Budget and TimeModel Selection Based on Budget and Time


AnalysisAnalysis�� Information Required For Dam Break ModelingInformation Required For Dam Break Modeling

-- Type of dam Type of dam –– rockfillrockfill earthcoreearthcore dam, dam, concrete face concrete face rockfillrockfill dam, concrete dam, dam, concrete dam, etc, etc,

-- Stage Storage CurveStage Storage Curve

-- Type of failure Type of failure –– overtopping and piping overtopping and piping

-- Climatic conditions Climatic conditions –– sunny day and sunny day and probable maximum flood probable maximum flood

-- Breach parameters Breach parameters -- breach bottom width breach bottom width and elevation, side and elevation, side slope, initial piping, slope, initial piping, breach formation time, breach formation time,

-- By International guidelinesBy International guidelines

-- Check using published equations Check using published equations


Analysis (Scenarios)Analysis (Scenarios)

�� Two (2) Two (2) tailwatertailwater conditions will be considered;conditions will be considered;

a)a) Governed by seawater level Governed by seawater level --

-- Dams (inner forest) far away from Dams (inner forest) far away from

coastal area and flood wave coastal area and flood wave

attenuated attenuated completelycompletely

-- Dam Dam catchmentcatchment too small compared too small compared

with overall with overall catchmentcatchment



�� Two (2) Two (2) tailwatertailwater conditions will be considered;conditions will be considered;

b)b) Not governed by seawater level Not governed by seawater level

-- Dams located near coastal areaDams located near coastal area

-- Dam Dam catchmentcatchment area is large area is large

compared to overall downstream compared to overall downstream

catchmentcatchment



�� Two (2) types of dam failure for 2 climatic Two (2) types of dam failure for 2 climatic

conditions ;conditions ;

a) a) Sunny daySunny day

OvertoppingOvertopping

Piping at dam foundation Piping at dam foundation

b)b) Probable maximum flood Probable maximum flood

OvertoppingOvertopping

Piping at dam foundation Piping at dam foundation

Dam Break Analysis Flow ChartDam Break Analysis Flow Chart

Setup HEC-RAS Model

Estimation of Dam Break Hydrograph

Evaluating Breach Characteristics and Sensitivity Analysis

Adopting Dam Break Hydrograph

Flood Routing of Various Dam Break Scenario (1D or 1/2D)

Preparation of Inundation Map

Typical Areas For Dam Break ModelingTypical Areas For Dam Break Modeling

Dam and reservoir

Downstream River

Confluence of river enter into main river

Town

Coastal Sea

Salient Features of Typical DamsSalient Features of Typical DamsDescriptionDescription InformationInformation

IIII CatchmentCatchment AreaArea 146 km146 km22

IIIIII PMFPMF 2,250 m2,250 m33/s/s

IVIV Dam:Dam:

-- TypeType

-- Dam HeightDam Height

-- Dam Crest LevelDam Crest Level

-- Storage Capacity at FSLStorage Capacity at FSL

Roller Compacted Concrete (RCC) Roller Compacted Concrete (RCC)

90 m90 m

RL 250mRL 250m

29,900 ML29,900 ML

VV Spillway:Spillway:

-- Type of Inlet WeirType of Inlet Weir

--Crest LengthCrest Length

Centre overflow with Stepped Chute, Roller Centre overflow with Stepped Chute, Roller

Bucket Energy DissipaterBucket Energy Dissipater

100m100m

VIVI DiversionDiversion

-- DiameterDiameter

-- LengthLength

Single conduit with 4.2m x 4.2m Single conduit with 4.2m x 4.2m

72m72m

Typical Stage Typical Stage –– Storage CurveStorage Curve

Design PMF (Design Report)Design PMF (Design Report)

Source: Greater Ipoh Water Supply Scheme II – Sg Kinta Dam Project : Design Report Oct 1999

Dam Breach FormationDam Breach Formation

Sources:Fread, D. L. Lewis, J. M. (1998), “MWS FLDWAV Model – Theoretical Development and User Documentation, Hydrological Research Laboratory Office of Hydrology, National Weather Services.

Breach Characteristics Based on Breach Characteristics Based on

GuidelinesGuidelines

Breach Characteristics Breach Characteristics -- Published Published

Equations (Width and Time)Equations (Width and Time)

Breach Characteristics Breach Characteristics -- Published Published

Equations (Peak Flow)Equations (Peak Flow)

Dam Break Input Parameter DataDam Break Input Parameter Data

Using HECUsing HEC--RAS Geometric DataRAS Geometric Data

�� The HECThe HEC--RAS model RAS model consist of 174 cross consist of 174 cross sections, starting from sections, starting from Dam to river mouthDam to river mouth

�� The length of the overall The length of the overall model is approx. 175km.model is approx. 175km.

�� Four (4) zones are Four (4) zones are classified:classified:�� Zone 1Zone 1: CS169: CS169--CS158 CS158

(Upper Reach of model)(Upper Reach of model)

�� Zone 2Zone 2: CS157: CS157--CS132 CS132 (Town to River Confluence)(Town to River Confluence)

�� Zone 3Zone 3: CS131: CS131--CS71 CS71 (Confluence to River Mouth (Confluence to River Mouth Area)Area)

�� Zone 4Zone 4: CS70: CS70--CS0 (River CS0 (River Mouth to Coastal Sea)Mouth to Coastal Sea)

Dam Break Input Parameter DataDam Break Input Parameter Data

�� ManningManning’’s Roughness, n parameters used s Roughness, n parameters used

for the model set up: River Sections for the model set up: River Sections

(Typical value 0.085) and Left and Right (Typical value 0.085) and Left and Right

Floodplain (Typical value 0.12)Floodplain (Typical value 0.12)

�� PMF was used as an Input Hydrograph.PMF was used as an Input Hydrograph.

�� The The ““Worst Case ScenarioWorst Case Scenario”” with maximum with maximum

dam breaching outflow and minimum dam breaching outflow and minimum

breach formation time is normally breach formation time is normally

simulatedsimulated

Major Problems in Dam Break Major Problems in Dam Break

ModelingModeling

�� Insufficient budget to acquire land, river Insufficient budget to acquire land, river

survey, satellite, IFSAR and LIDAR datasurvey, satellite, IFSAR and LIDAR data

�� Dam break river model not suitable for low Dam break river model not suitable for low

flow simulation due to insufficient river dataflow simulation due to insufficient river data

�� Homogenous survey data (either fine and Homogenous survey data (either fine and

coarse) are required to avoid instability coarse) are required to avoid instability

�� Rapidly rise dam break outflow hydrograph Rapidly rise dam break outflow hydrograph

lead instability lead instability

Major Problems in Dam Break Major Problems in Dam Break

ModelingModeling

�� HotHot--start or large initial flow will have to key start or large initial flow will have to key

in the model for simulationin the model for simulation

�� Large base flow required for controlling Large base flow required for controlling

stabilitystability

�� Small time step and close grid distance Small time step and close grid distance

required for controlling stability (Courantrequired for controlling stability (Courant––

FriedrichsFriedrichs––LewyLewy condition, CFL condition) condition, CFL condition)

-- longer simulation time longer simulation time

-- Insufficient survey dataInsufficient survey data

Design PMF Inflow HydrographDesign PMF Inflow Hydrograph

Source: Greater Ipoh Water Supply Scheme II – Construction of sg Kinta Dam and Associated Works

2255

Probable Maximum Flood – Inflow Hydrograph

Dam Breach Plot (Dam Breach Plot (Worst CaseWorst Case))

Linear Breach DevelopmentLinear Breach Development

Typical Example of Assessment of Typical Example of Assessment of

Downstream Conditions To Sea LevelDownstream Conditions To Sea LevelNormal Normal

Depth (m)Depth (m)Water Level (m) at Water Level (m) at

CS 0 CS 0 Tidal Range (m) Tidal Range (m)

Near River Mouth Near River Mouth

AreaArea

Tidal Range (m) at Tidal Range (m) at

SeaSea

0.0010.001 --3.273.27

+1.92 to +1.92 to –– 1.701.70

HAT = 1.68HAT = 1.68

MHWS = 1.20MHWS = 1.20

MHWN = 0.49MHWN = 0.49

MSL = 0.00MSL = 0.00

MLWN = MLWN = --0.480.48

MLWS = MLWS = --1.191.19

LAT = LAT = --1.751.75

0.00010.0001 0.140.14

0.000010.00001 4.584.58

0.000020.00002 3.23.2

0.000030.00003 2.472.47

0.000040.00004 1.971.97

0.000050.00005 1.491.49

Conclusion: Water Level at River Mouth will not be influenced by Dam Breach Flow

Typical Water Levels at Typical Water Levels at

DownstreamDownstream

1.92m

Result of Dam Break Analysis Result of Dam Break Analysis

With PMFWith PMF

Full Formulation Full Formulation

Time (hr)Time (hr)Water Surface Water Surface

ElevElev (m)(m)IpohIpoh Town Bank Town Bank

Level (m)Level (m)Inundated Water Inundated Water

Level (m)Level (m)

0.10.1 76.2676.26

70.8170.81

(Selected Spot (Selected Spot

Level at Level at

CH157.00m)CH157.00m)

5.455.45

0.20.2 76.2676.26 5.455.45

0.30.3 76.2676.26 5.455.45

0.50.5 76.2676.26 5.455.45

11 76.2676.26 5.455.45

22 76.2676.26 5.455.45

33 72.7172.71 1.91.9

44 72.6172.61 1.81.8

55 72.5172.51 1.71.7

Not Relevant

Dam Break Outflow Hydrograph Dam Break Outflow Hydrograph

Probable Maximum FloodProbable Maximum Flood

DambreakDambreak Hydrograph with PMFHydrograph with PMF--Full Full

Formulation Time (0.1 hr) Formulation Time (0.1 hr)


Formulation Time (0.2 hr)Formulation Time (0.2 hr)





Result of Dam Break AnalysisResult of Dam Break Analysis

Dam Break OnlyDam Break Only

Full Formulation Full Formulation

Time (hr)Time (hr)Water Surface Water Surface

ElevElev (m)(m)Town Bank Level Town Bank Level

(m)(m)Inundated Water Inundated Water

Level (m)Level (m)

0.10.1 76.2676.26 70.8170.81

(Selected Spot (Selected Spot

Level at Level at

CH157.00m)CH157.00m)

5.455.45

0.20.2 77.7477.74 6.936.93

0.30.3 78.0978.09 7.287.28

Dam Break Outflow Hydrograph Dam Break Outflow Hydrograph

Sunny DaySunny Day

Sunny Day Sunny Day KintaKinta DambreakDambreak Hydrograph Hydrograph

with Time to Breach (0.1 hr)with Time to Breach (0.1 hr)

Sunny Day Sunny Day DambreakDambreak Hydrograph Time to Hydrograph Time to

Breach (0.2 hr)Breach (0.2 hr)

Sunny Day Sunny Day KintaKinta DambreakDambreak Hydrograph Hydrograph

Time to Breach (0.3 hr)Time to Breach (0.3 hr)

Use of Dam Break Simulation Use of Dam Break Simulation

Results For Inundation Map, Results For Inundation Map,

Emergency Response PlanEmergency Response Plan

�� Inundated maps are extended up to the Inundated maps are extended up to the

minimum contour line of approx. 20m MSLminimum contour line of approx. 20m MSL

�� Usually At downstream reaches where contour Usually At downstream reaches where contour

is <20m historical flood coverage area is used.is <20m historical flood coverage area is used.

�� Checking results by comparing historical flood Checking results by comparing historical flood

areasareas

Typical Inundation MapsTypical Inundation Maps

Part 2 Part 2 -- Socio Economic StudySocio Economic Study

Objectives of SocioObjectives of Socio--economic Studyeconomic Study

�� Determine the extent of flood damage Determine the extent of flood damage

based on the flood maps at the time of the based on the flood maps at the time of the

flood event.flood event.

�� Determine the affected spatial areas and Determine the affected spatial areas and

scale of damage.scale of damage.

�� Delineate risk zones and flood risks.Delineate risk zones and flood risks.

�� Recommend risk reduction when a dam Recommend risk reduction when a dam

breaks.breaks.

Approach and MethodologyApproach and Methodology

Flood mapTopography

map

GIS

Field Data Statistics

Results and Discussions

Delineation Delineation

of Flooded of Flooded

AreasAreas

Part 3 Emergency Response PlanPart 3 Emergency Response Plan

Objectives & Content of ERPObjectives & Content of ERP

�� Objectives Objectives

�� safeguard lives & to reduce damage in the safeguard lives & to reduce damage in the

event of Dam failureevent of Dam failure

�� ContentsContents

�� Monitoring procedures during emergenciesMonitoring procedures during emergencies

�� Organizational structureOrganizational structure

�� procedures on how to deal with emergenciesprocedures on how to deal with emergencies

MKN MKN ArahanArahan No.20No.20Purpose: outlines emergency and aid procedures to Purpose: outlines emergency and aid procedures to

manage inland disasters by the governmentmanage inland disasters by the government

Level ILevel I Disaster is localized & not seriousDisaster is localized & not serious

Under control & no potential to spreadUnder control & no potential to spread

Risk to lives and properties is smallRisk to lives and properties is small

No major disruption to daily activitiesNo major disruption to daily activities

can be managed by authorities at district levelcan be managed by authorities at district level

Level IILevel II Disaster affects > 2 districtsDisaster affects > 2 districts

potential to spreadpotential to spread

High risk to lives and propertiesHigh risk to lives and properties

Major disruption to daily activitiesMajor disruption to daily activities

Complex & involve difficult search & rescueComplex & involve difficult search & rescue

can be managed by authorities at State levelcan be managed by authorities at State level

Level IIILevel III Complex in natureComplex in nature

Affect large area or > 2 statesAffect large area or > 2 states

Need to be managed at Federal LevelNeed to be managed at Federal Level

MKN/ EAP: Level II AgenciesMKN/ EAP: Level II AgenciesJawatankuasaJawatankuasa PengurusanPengurusan dandan BantuanBantuan BencanaBencana NegeriNegeri

�� ChairmanChairman: : YB. YB. SetausahaSetausaha KerajaanKerajaan NegeriNegeri

�� SecretarySecretary: : PengarahPengarah BahagianBahagian KeselamatanKeselamatan Negara Negara

(BKN) (BKN) NegeriNegeri

�� MembersMembers: :

1.1. KetuaKetua Polis Polis NegeriNegeri

2.2. PanglimaPanglima BrigedBriged, ATM, ATM

3.3. PengarahPengarah BombaBomba dandan PenyelamatPenyelamat NegeriNegeri

4.4. PengarahPengarah KesihatanKesihatan NegeriNegeri

5.5. PengarahPengarah JKR JKR NegeriNegeri

6.6. PengarahPengarah Jab Jab KebajikanKebajikan MasyarakatMasyarakat NegeriNegeri

7.7. PengarahPengarah PeneranganPenerangan NegeriNegeri

MKN/ EAP: Level II AgenciesMKN/ EAP: Level II Agencies�� MembersMembers: :

8.8. PengarahPengarah PenyiaranPenyiaran NegeriNegeri

9.9. PengarahPengarah PertahananPertahanan AwamAwam NegeriNegeri

10.10. PengarakPengarak JAS JAS NegeriNegeri

11.11. PengarahPengarah Jab Jab KeselamatanKeselamatan dandan KesihatanKesihatan PekerjaanPekerjaan NegeriNegeri

12.12. PengarahPengarah KajicuacaKajicuaca NegeriNegeri

13.13. PengarahPengarah JabatanJabatan PenerbanganPenerbangan AwamAwam

14.14. PengarahPengarah JPS JPS NegeriNegeri

15.15. PengarahPengarah Jab Jab PenyiasatanPenyiasatan KajibumiKajibumi NegeriNegeri

16.16. PengarahPengarah JPJJPJ

17.17. PengarahPengarah IkatanIkatan RelawanRelawan RakyatRakyat Malaysia (RELA)Malaysia (RELA)

18.18. PengurusPengurus SykSyk TelekomTelekom Malaysia Malaysia BhdBhd (STMB) (STMB) NegeriNegeri

19.19. PengurusPengurus TenagaTenaga NasionalNasional BerhadBerhad (TNB) (TNB) NegeriNegeri

EAP Road MapEAP Road Map

�� KMN to establish a KMN to establish a ““Command & ControlCommand & Control””

Committee consist of 2 levels to ensure Committee consist of 2 levels to ensure

emergency responds are orderly, direct and emergency responds are orderly, direct and

effective. effective.

1.1. Pos Pos KawalanKawalan TempatTempat KejadianKejadian (PKTK)(PKTK)

�� Lead by PDRMLead by PDRM

�� Establish Communication Network with All AgenciesEstablish Communication Network with All Agencies

2.2. PusatPusat KawalanKawalan OperasiOperasi BencanaBencana (PKOB)(PKOB)

�� Setup in District Office, or Rapid Responds Center/ Setup in District Office, or Rapid Responds Center/

Room in BKN Room in BKN NegeriNegeri

�� Establish Complete Communication System in PKOBEstablish Complete Communication System in PKOB

EAP Zoning EAP Zoning -- CategorizationCategorization�� Emergency Teams to be divided into 3 Emergency Teams to be divided into 3

categories for efficient & effective coordination:categories for efficient & effective coordination:

1.1. Primary Disaster/Rescue Agencies, Primary Disaster/Rescue Agencies, egeg. SMART, . SMART,

PDRM, JBPM, etcPDRM, JBPM, etc

2.2. Disaster/ Rescue Support Agencies, Disaster/ Rescue Support Agencies, egeg. Civil . Civil

DefenceDefence Department (Department (JabatanJabatan PertahananPertahanan AwamAwam))

3.3. Support & Rescue Agencies, Support & Rescue Agencies, egeg. JKR, RELA, . JKR, RELA,

PBSM, TNB, etcPBSM, TNB, etc

�� In addition, the disaster area to be divided into 3 In addition, the disaster area to be divided into 3

zones: zones:

�� RedRed ZonesZones

�� YellowYellow ZonesZones

�� GreenGreen ZonesZones

Disaster Area ZonesDisaster Area Zones

DISASTER ZONEDISASTER ZONE

Operation Area of Search Operation Area of Search

& Rescue Task Force& Rescue Task Force

ATM

PDRM

Bomba

Medical

Respond

Services

SMART

Civil

Defense

Dept

Other Rescue

Agencies

Disaster

ManagementPost

Media Reporting &

Management CenterMortuary

Rest

Area

Victim

Counseling

Unit

Support Agencies &

Volunteer

Organizations

Counseling

Center

Food

Storage/

Supply Unit

Entry Zones

RedRed ZoneZone: Area for

Primary Rapid Respond

Units with Special Skills

YellowYellow ZoneZone: Area for

PTTK, Main Rescue Post &

Rescue Support Units

GreenGreen ZoneZone: Area for

Media, Victim Counseling,

Food Supply, Mortuary,

Rest & Relevant Support Units

Operation

Post

Data Required For Detailed ERPData Required For Detailed ERP

�� Land use information used for Land use information used for Safe Area Safe Area

Identification Identification

�� Simulation Results Based on Topographical Simulation Results Based on Topographical

maps and Google Data For Preliminarily Dam maps and Google Data For Preliminarily Dam

Break Flood LevelBreak Flood Level

�� Detailed Information can be obtained using Detailed Information can be obtained using

IFSAR data for selected important urbanized IFSAR data for selected important urbanized

areas and utilities (such as water treatment, areas and utilities (such as water treatment,

power supply, hospital, telecommunication power supply, hospital, telecommunication

center, etc.)center, etc.)

YB Menteri (dilantik of YAB PM)PengerusiJ/K Pengurusan & Bantuan BencanaPusat

YB SUK NegeriPengerusiJ/K Pengurusan dan BantuanBencana Negeri

Pegawai DaerahPengerusiJ/K Pengurusan dan BantuanBencana Daerah

PusatKawalanM’sia

Bilek GerakanBKNSMARTPertahananJBPN

Pusat KawalanKontingen

Pusat KawalanDaerah

Pusat KawalanOperasi Bencana(PKOB)Bilik Gerakan BKN

PKOB(BilikGerakanBKN Negeri)

PKOB(BilikGerakanPejabatDaerah)

Pos Kawalandi Tempatkejadian

Government Disaster Management Mechanism

Notification Notification

ProcedureProcedure

Emergency Event

Dam Manager

Dam Office (Site)

Dam Office (HQ)

District Level(Pos Kawalan)Polis Bomba

JPBBN

Dam Company’s Emergency Response Team

Director of Emergency Operation(Executive Director, Dam Company)

Alternate/ Deputy Director of Emergency Operation(COO, Dam Company)

Dam Operation Centre (DOC)

Dam Assessment TeamHead Office Operation Centre(HOOC)

Dam Engineer (Leader)Civil EngineerMechanical EngineerElectrical & instrumentation Engineer

Dam Emergency Controller(Dam Manager) Head Office

Emergency Controller(Head O&M Dept)Dam ET

Dam Comm OfficerCivil EngineerMechanical EngineerElect & instr EngineerTechniciansGeneral workersReceptionist

Head Office ETHead Offc Comm OfficerManager (Civil)Manager (M&E)Head EQLHead HQLReceptionist

Dam Office’s ER Team

Roles/ ResponsibilitiesRoles/ Responsibilities

Director of Director of

Emergency Emergency

Operation (ED)Operation (ED)

�� overall responsible for directing operationsoverall responsible for directing operations

�� decide on the levels of the emergencydecide on the levels of the emergency

��Notify the JPBBN of emergencyNotify the JPBBN of emergency

Alternate/ Deputy Director of Emergency Operation (COO)

�� assist DEOassist DEO

�� take over roll of DEO if ED not availabletake over roll of DEO if ED not available

Dam Assessment Dam Assessment

TeamTeam�� conduct routine dam inspection (normal time)conduct routine dam inspection (normal time)

�� assess emergency situation and dam assess emergency situation and dam

conditions during an emergencyconditions during an emergency

�� identify & undertake preventive measuresidentify & undertake preventive measures

��Advise DEO on dam integrity and necessity for Advise DEO on dam integrity and necessity for

evacuationevacuation

Roles/ ResponsibilitiesRoles/ Responsibilities

Dam EngineerDam Engineer Normal TimeNormal Time

�� routine dam inspectionroutine dam inspection

�� advise dam company Mgmt on dam conditionsadvise dam company Mgmt on dam conditions

�� identify and recommend any remedial actionsidentify and recommend any remedial actions

EmergencyEmergency

�� lead the Dam Assessment Teamlead the Dam Assessment Team

Dam Emergency Controller (Dam Manager)

�� alert dam company ED/ COO of emergencyalert dam company ED/ COO of emergency

��Initial actions to reduce threatsInitial actions to reduce threats

�� assist the DAT in assessing the conditionsassist the DAT in assessing the conditions

�� set up Dam Operation Centreset up Dam Operation Centre

�� Update & maintain close liaison with HOOCUpdate & maintain close liaison with HOOC

�� Alert the district authorities when warranted Alert the district authorities when warranted

Head Office Head Office

Emergency Emergency

Controller Controller

(Head O&M)(Head O&M)

�� set up and manage HOOCset up and manage HOOC

��Alert & dispatch DAT to siteAlert & dispatch DAT to site

��Maintain close coMaintain close co--coordination with DOCcoordination with DOC

��Update DEO and Deputy DEOUpdate DEO and Deputy DEO

RL 227

RL 221.3 Alert ( 1: 100 flood)

RL 221.58 Warning ( 1: 500 flood)

RL 224.6 Danger ( PMF)

RL 226 Evacuation

RL 220 NWL

Typical Emergency Notification Flowchart -Overtopping

Head O&MDam Operator Staff

Typical Emergency Notification Flowchart Typical Emergency Notification Flowchart –– Overtopping (cont)Overtopping (cont)

5

5

5

99

Typical Emergency Notification Flowchart Typical Emergency Notification Flowchart –– Overtopping (cont)Overtopping (cont)

Typical Piping EventTypical Piping Event

Stage Condition

Stage 1 : Alert Abnormal increase in seepage flowrate

Stage 2 : Warning Steady increase in flowrate with signs of

loss of embankment materials (e.g.

muddy coloration, seepage water

containing embankment material, etc)

with / without signs of wet patches on

dam embankment

Stage 3 : Danger Seepage flowrate remains high and dam

shows signs of deformation/ failure

Stage 4 : Evacuation Dam failure may be imminent

Typical Structural Failures EventTypical Structural Failures Event

�� Abnormal/ excessive embankment deformationAbnormal/ excessive embankment deformation

�� LandslidesLandslides

�� EarthquakeEarthquake

�� failure of critical structures (e.g. spillway), etc.failure of critical structures (e.g. spillway), etc.

�� for earthquakefor earthquake

�� Dam Manager immediately call Geological Survey Dam Manager immediately call Geological Survey Department to determine magnitude and epicenterDepartment to determine magnitude and epicenter

�� The Dam Manager immediately inspect the Dam to The Dam Manager immediately inspect the Dam to determine if there is any structural damagedetermine if there is any structural damage

Typical Structural Failures Event (Cont)Typical Structural Failures Event (Cont)

Stage of Emergency Condition

Stage 1 : Alert Structural failure is noted

Stage 2 : Warning Situation worsens

Stage 3 : Danger

Situation continues to worsens

in spite of preventive

actions

Stage 4 : Evacuation Dam failure may be imminent

Termination of EmergencyTermination of Emergency

�� no further signs of distressno further signs of distress

�� approval of the Dam Assessment Teamapproval of the Dam Assessment Team

�� Dam Emergency Controller and Head Dam Emergency Controller and Head

Office Emergency Controller to inform Office Emergency Controller to inform

Polis, Polis, BombaBomba, District Officers, JPBBN , District Officers, JPBBN

and other relevant authoritiesand other relevant authorities

Risk ManagementRisk Management

1.1. Routine Monitoring/ SurveillanceRoutine Monitoring/ Surveillance

�� Carry out routine monitoring by Dam Carry out routine monitoring by Dam

Operation TeamOperation Team

�� Refer to Dam O&M ManualRefer to Dam O&M Manual

�� Personnel trained to recognize signs of Personnel trained to recognize signs of

distressdistress

Risk Management (cont)Risk Management (cont)2. Surveillance by Dam Engineer/ DAT2. Surveillance by Dam Engineer/ DAT

DAT conduct onDAT conduct on--site dam inspection every 3 monthssite dam inspection every 3 months

inspect:inspect:

�� upstream and downstream faces for signs of slope upstream and downstream faces for signs of slope failures, cracks, settlement or seepagefailures, cracks, settlement or seepage

�� spillways for clogging, cracking or leakingspillways for clogging, cracking or leaking

�� seepage water at the seepage chambers for seepage water at the seepage chambers for clogging, turbidity, muddy water or increased in flowclogging, turbidity, muddy water or increased in flow

�� reservoir and downstream areas for landslidesreservoir and downstream areas for landslides

�� take dam instrument readings and review past take dam instrument readings and review past instrument readings.instrument readings.

Risk Management (cont)Risk Management (cont)3. Maintenance3. Maintenance

�� routine maintenance especially routine maintenance especially m&em&e equipmentequipment

�� ensure equipment in good working conditions ensure equipment in good working conditions

especially in times of emergencies.especially in times of emergencies.

4. Drills4. Drills

�� to simulate and test the readiness of Dam Company to simulate and test the readiness of Dam Company

emergency response systememergency response system

�� Practice makes perfectPractice makes perfect

�� results of drills analyzedresults of drills analyzed

�� Weakness/ shortcoming identified and solutions to Weakness/ shortcoming identified and solutions to

overcome identifiedovercome identified

Preventive Measures During EmergenciesPreventive Measures During Emergencies

1. Imminent Overtopping by Flood Waters1. Imminent Overtopping by Flood Waters

�� open drain or flood gates to maximum dischargeopen drain or flood gates to maximum discharge

�� place sandbags along the dam crest to increase place sandbags along the dam crest to increase

freeboardfreeboard

�� place riprap or sandbags in damaged areas of damplace riprap or sandbags in damaged areas of dam

�� provide erosion protection on downstream slope by provide erosion protection on downstream slope by

placing rip rap or other appropriate materialplacing rip rap or other appropriate material

�� divert flood waters around dam if possibledivert flood waters around dam if possible


2. Erosion of Dam by Seepage Through the Embankment, 2. Erosion of Dam by Seepage Through the Embankment, Foundation or AbutmentsFoundation or Abutments

�� plug seepage with riprap, plug seepage with riprap, bentonitebentonite, sandbags, soil, , sandbags, soil, plastic sheeting, etc if the leak is on the upstream plastic sheeting, etc if the leak is on the upstream face of the damface of the dam

�� lower reservoir level until flow decreases to a nonlower reservoir level until flow decreases to a non--erosive velocity or stops leakingerosive velocity or stops leaking

�� place sand and gravel filter over seepage exit area place sand and gravel filter over seepage exit area to minimize loss of embankment materialsto minimize loss of embankment materials

�� continue lowering the reservoir level until seepage continue lowering the reservoir level until seepage stops or is controlled. Refill reservoir to normal stops or is controlled. Refill reservoir to normal levels only after seepage is repairedlevels only after seepage is repaired


3. Slide or Slope Failure on Upstream or 3. Slide or Slope Failure on Upstream or

downstream Slope or Embankmentdownstream Slope or Embankment

�� lower reservoir water level at a rate and to a safe lower reservoir water level at a rate and to a safe

elevation (seek advise of Dam Engineer)elevation (seek advise of Dam Engineer)

�� restore lost freeboard by placing sandbags or filling restore lost freeboard by placing sandbags or filling

with materialswith materials

�� stabilize slide by weighing the toe area with stabilize slide by weighing the toe area with

additional soil, rock or graveladditional soil, rock or gravel

4. Failure of Spillway Structure or outlet4. Failure of Spillway Structure or outlet

�� lower the water level to a safe elevationlower the water level to a safe elevation

�� implement temporary measures to protect the implement temporary measures to protect the

damaged structuredamaged structure

Post Emergency and ERP ReviewPost Emergency and ERP Review

4. Post Emergency4. Post Emergency�� Carry out post mortem to analyze the handling of Carry out post mortem to analyze the handling of

the emergency and to determine any need for the emergency and to determine any need for further improvement.further improvement.

5. ERP Review5. ERP Review�� review and update once every year at a designated review and update once every year at a designated

date.date.

�� followed by staff training on the updated ERP.followed by staff training on the updated ERP.

�� Any modifications as a result of the update or Any modifications as a result of the update or training exercise shall be attached.training exercise shall be attached.

�� The Update, Exercise and Training Form in The Update, Exercise and Training Form in Appendix E shall be completed and submitted to Appendix E shall be completed and submitted to dam companydam company’’s management.s management.

A p p e n d i x E

E M E R G E N C Y R E S P O N S E P L A N F O R S G S E L A N G O R D A M

U P D A T E , E X E R C I S E A N D T R A I N I N G

T h e E m e r g e n c y R e s p o n s e P l a n f o r t h e S g S e l a n g o r D a m w a s u p d a t e d o n … … … … . .( d a t e ) ,

a … … … … … … … … … … … … … … … ..( t y p e : t a b l e t o p , f u n c t i o n a l ) e x e r c i s e w a s p e r f o r m e d o n

… … … … … … … ( d a t e ) a n d s t a f f t r a i n i n g o n t h e i m p l e m e n t a t i o n o f t h i s E R O P w a s p r o v i d e d o n

… … … … … … … ( d a t e ) .

A n y n e e d e d m o d i f i c a t i o n s a s a r e s u l t o f t h e u p d a t e , o r t r a i n i n g e x e r c i s e a r e a t t a c h e d a n d r e v i s i o n s

h a v e b e e n p r o v i d e d t o o t h e r p l a y e r s w i t h r e s p o n s i b i l i t i e s l i s t e d i n t h e E R P .

M a n a g e r ( E n v i r o n m e n t a l / Q u a l i t y / L i a i s o n ) : … … … … … …

D a t e : … … … … … … … … … … … … .

* T h i s f o r m i s t o b e s u b m i t t e d t o S P L A S H M a n a g e m e n t b y J u l y 1s t

o f e v e r y y e a r f o l l o w i n g t h e

a p p r o v a l o f t h e p l a n .

For Dam

Emergency Response FacilitiesEmergency Response Facilities

�� Emergency Control Emergency Control CentresCentres

�� Dam Operation Centre shall be located at Dam Operation Centre shall be located at

the dam site itself where accurate and up to the dam site itself where accurate and up to

date information and assessment are date information and assessment are

available on the spot.available on the spot.

�� The Head Office Operation Centre shall be The Head Office Operation Centre shall be

located at Dam Companylocated at Dam Company’’s headquarters.s headquarters.

Dam Operation Centre

1 Telecommunication system consisting of fixed line and mobile

telephone systems, facsimile, walkie-talkie, etc

2 Back-up power sources and batteries in case of power failure

3 Back-up lightings

4 Copy of Dam Operation and Maintenance Manual

5 Latest copy of Sg Selangor Dam ERP and Dambreak Study Report

6 Copy of Dam drawings

7 List of contractors and construction machineries contractors to be

contacted (also contained in ERP)

8 Inundation map (also contained in ERP)

Dam

1 Loud hailer and siren

2 Transportation

Land transportation

Water transportation

3 First aid kits and medical equipment

4 Ready stockpile of construction materials e.g. sandbags, riprap

THANK YOUTHANK YOU

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