A river basin approach to building resilience in critical infrastructure: Kelani River Basin, Sri Lanka
Presented as part of the webinar series: Adaptation in an age of uncertainty: tools for climate resilient water management approaches
Why a river basin approach?
• Physical, geographical, and functional relationships within the basin
• Sustainability of infrastructure investments in inextricably linked with effective area-wide planning
• Application of hydrological and hydraulic modellings results
• Existing multi-sector and multi-stakeholder planning efforts
• River basin unit is particularly valuable in the context of a changing climate
Kelani River Basin
Kelani River Basin Topography
Kelani River Basin Infrastructure
Ro
ad N
etw
ork
Critical Infrastructure Complexes
Kel
aniR
iver
Port Facilities
Kela
niV
alle
y R
ailw
ay
National GridWater Storage Reservoirs
Hydropower Plants
T & D System
Laxapana Hydropower Complex
Water Intake
Water Treatment Plants
Water Distribution
System
Water supply complex
Oil Refinery
Oil Distribution Systems
Oil Storage
Thermal Power Plants
T & D System
Thermal power complex
Laxapana Hydropower Complex
ICEM CAM approachVulnerability Assessment and Adaptation Measures
Climate Change Adaptation Methodology (CAM) • Flexible methodology to climate change adaptation planning
• Framework for systematically identifying climate change factors, impacts, and adaptation responses
• Can be applied at different spatial scales
Phases of the CAM
• Impact and Vulnerability Assessment
• Adaptation Planning
• Implementation and Feedback
ICEM CAM Approach: Vulnerability AssessmentThreat Impact Adaptation
Meteorology: Air temperature, humidity,
rainfall, storms, and cyclones
Hydrology: River discharge, water levels, flood depth & duration, sea
level rise
Hydro-dynamics: River water temperature, flow
velocity, river-bank erosion, channel & floodplain water
levels
Sensitivity
Design
Materials
Siting
Maintenance
Impact
Over-topping
Scour/wash-out
Loss of bearing capacity
Disruption to traffic
Areas become isolated
Reduce design life
Capacity
Technologies
Material Supply
Financial Resources
Expertise and Staffing
Management Systems
Policies and procedures
Intensity
Aspect
Exposure
Duration
Location
Magnitude
Asset inventory and priority
setting
Past extreme events and
impacts
CC threat assessment
profiles
Adaptation audit of past
measures
Socio-economic trends
assessment
Natural system trends
assessment
Vu
lne
rab
ilit
y
Applying the ICEM CAM
✓
Climate Change in the Kelani Basin
Southwest Monsoon Precipitation - Wettest
Southwest Monsoon Precipitation - Driest
Historical Precipitation – Lower Basin
y = -1.7293x + 2329.1
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
1948
1951
1954
1957
1960
1963
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
1999
2002
2005
2008
Pre
cip
itation (
mm
/y)
Historical Flooding (May 2016)
Landslide Susceptibility
WEAP Model
Basin-wide outflow
Hydropower Production
Applying the ICEM CAM
✓✓
CAM Approach – Laxapana Complex
Threat Interpretation of threat Exposure SensitivityImpact
levelImpact summary
Adaptive
capacityVulnerability
Droughts
Increases in
temperature and
decreases in
precipitation, as is
projected during NEM
seasons by the
driest/coldest model
(GFDL-ESM2M) under
TA9191, may increase
the risk of droughts.
High High High
Intermittent droughts caused by
extended dry spells lead to
reduced water level in
hydropower reservoirs.
Direct impact: Reduces the
generation output of HPPs
Indirect impact: Increases the
share of thermal PPs at
increased generation costs and
higher emissions
Low High
CAM Approach – Laxapana Complex
ThreatInterpretation of
threatExposure Sensitivity
Impact
levelImpact summary
Adaptive
capacityVulnerability
Landslides
occurring
as a result
of extreme
precipitatio
n events
The number of heavy
precipitation days is
projected to increase
from 70 to 83-87 days
per year and very
heavy days from 25 to
32-37 days per year.
Extreme precipitation
events often contribute
to landslides in the
UKB.
Medium Medium Medium
Direct impact: landslide events
into reservoirs reduce overall
reservoir capacity
Direct impact: landslides can
damage or destroy
transmission towers resulting
in intermittent disruption of
power supply in local areas
Indirect impact: landslides
often impact roads, restricting
travel of operations staff and
equipment to reach
hydropower facilities
Medium Medium
CAM Approach – Water Supply Complex
Threat Interpretation of threat Exposure SensitivityImpact
levelImpact summary
Adaptive
capacityVulnerability
Salinity
intrusion
Increases in temperature
and decreases in
precipitation, as
projected during NEM
season by the
driest/coldest model
under TA9191, will likely
lead to periods of
reduced flow. As
demonstrated by WEAP
modelling, saline
intrusion becomes an
increasing problem
during low flows,
especially when
combined with sea level
rise.
High High High
Salinity intrusion reduces the
quality of water for domestic and
industrial uses, and in extreme
cases may make water unusable
Direct impact: Directly affects the
intake of water from river forcing
shut down of the operations until
salinity levels return to normal.
Direct impact: Forces the
discharge of water from UKB
hydroelectric reservoirs, if water is
available, to maintain the river
flow, reducing the generation
output of HPPs and increasing the
share of thermal PPs
Medium High
Adaptation Measures
Consideration of the CI Complex
• Considered both sector specific complexes and interdependencies between infrastructure sectors
• Adaptation options drawn from stakeholder input
• Includes grey, green, bioengineering, economic instruments, natural systems management, revisions to policies and regulations, and institutional policies
Adaptation – Laxapana Complex
Complex Threats Adaptation options
Laxapana hydro-electric complex
Increased temperature
and decreased
precipitation contributing
to droughts
Raise dam heights to increase water storage
Deploy floating solar PV panels to reduce evaporation and
provide additional capacity of power generation through
renewable means
Develop pumped-storage hydroelectric facilities
Extreme precipitation
events contributing to
landslides
Build retaining walls on uphill slopes above vulnerable infrastructure
Plant permanent trees and ground-stabilizing vegetation
Extreme precipitation
events contributing to soil
erosion
Periodical dredging of reservoirs
Increase vegetation cover in watershed areas (e.g. planting trees)
Reforestation of agricultural lands (such as tea plantations) located on erosion-prone slopes near reservoirs
Adaptation – Laxapana Complex
Complex Threats Adaptation options Feasibility Effectiveness Priority
Laxapanahydro-electric complex
Increased temperature
and decreased
precipitation
contributing to droughts
Raise dam heights to increase water storage Very Low High Medium
Deploy floating solar PV panels to reduce
evaporation and provide additional capacity of
power generation through renewable means
Low Medium High
Develop pumped-storage hydroelectric facilities High High High
Extreme precipitation
events contributing to
landslides
Build retaining walls on uphill slopes above vulnerable infrastructure
High High High
Plant permanent trees and ground-stabilizing vegetation
High High High
Extreme precipitation
events contributing to
soil erosion
Periodical dredging of reservoirs Low Medium Medium
Increase vegetation cover in watershed areas (e.g. planting trees)
High High High
Reforestation of agricultural lands (such as tea plantations) located on erosion-prone slopes near reservoirs
Very low High Medium
Complex-Wide Adaptation
• Recognizing co-benefits
• Multi-criteria economic assessment
• Adaptation Action plan: • Policy
• Institutional
• Regulatory
• Social
• Ecosystem/Nature-based
Key Lessons:• Critical Infrastructure Complexes: Looking beyond single
asset management
• Mainstreaming climate risk into development planning cycles
• On site knowledge (community-based approach) is foundation of vulnerability assessment and adaptation planning
Key Lessons:• Nature-based solutions and hybrid measures
• “Adaptive” adaptation
• Consultation and communications strategies for stakeholder engagement
• Physical - Ecological – Financial –Social/Institutional Resilience are all connected