1. Assessing the Resilience of Water Supply Systems in Oman
By:
Dr. Kassim Mana Al Jabri
Public Authority for Electricity and Water
Sultanate of Oman

2. AGENDA Problem Statement Aim and Objectives Research Methodology
Results of Risk Assessment
Evaluation of Resilience
Discussion of Research Findings
Conclusions

3. Problem Statement
Water supply systems in Oman are exposed to a range of risks, due to both natural and man-made hazards.
Natural disasters, especially tropical cyclone such as Gonu in 2007, cause immense damage to water supply systems in Oman.
There are also risks to water supplies arising from operational practices, perhaps currently the most important being the water losses problem.
This research developed an integrated approach to identify and rank the risks and recommends methods of analysis and assessment to improve the resilience of water supply systems in Oman

4. Aim and Objectives Aim:
To bring an understanding of how resilience to various hazards (natural and manmade) in water supply systems can be developed in the Sultanate of Oman.
To developed an integrated approach to identify and rank the risks and recommends methods of analysis and assessment to improve the resilience of water supply systems in Oman
Objective:
Assessing the resilience of water supply systems in Oman through analysis and assessment of risks, including desalination plants, transmission pipelines and water distribution network, and to determine how these risks may be reduced through effective measures of mitigation.

5. Research Methodology
Research Approach

6. Risk Assessment Approach
Due to the lack of adequate information, semi-quantitative risk assessment approach, namely, Coarse Risk Analysis (CRA) is used for the analysis and assessment of risks for water supply systems in Oman.
The scope of the CRA consisted of:
Identifying hazardous events related to water supply system.
Estimate the probability and consequence for each hazardous event.
Ranking the hazardous events with respect to their risk.
Determine risk as: Risk = Likelihood × Consequence
Assessing the need for risk reduction options.
Risk factors were identified, ranked and scored at a stakeholder workshop.
CRA is presenting probability as rare, unlikely, possible, likely, certain, and consequence as: minor, major, and severe. The combined categories are inserted in a risk matrix show numeric description of risk ratings.

7. Likelihoods, Consequences Tables
Qualitative Measures of Likelihood
Consequence of Hazard Events for Transmission Mains
Severity
Definition
Score A
<500 properties without water for 12 hours 1 B
<1,000 properties without water for 12 hours or one industrial customer
<500 properties without water for 24 hours 2 C
<10,000 properties without water for 12 hours or two to ten industrial customers
<1,000 properties without water for 24 hours or one industrial customer
<500 properties without water for 48 hours 4 D
<50,000 properties without water for 12 hours or more than ten industrial customers
<10,000 properties without water for 24 hours or two to ten industrial customers
<1000 properties without water for 48 hours or one industrial customer
<500 properties without water for 2-5 days 8 E
100,000 properties without water for 12 hours or more than one hundred industrial customers
<50,000 properties without water for 24 hours or more than ten industrial customers
<10,000 properties without water for 48 hours or two to ten industrial customers
<1000 properties without water for 2-5 days or one industrial customer
<500 properties without water for >5 days 16
Level
Description
Score 1
One in 50 to 100 years 2
One in 20 to 50 years 3
One in 5 to 20 years 4
One in 1 to 5 years 5
More than one per year
Consequence of Event Duration for Desalination
Severity
Definition
Score A
< 12 hours partial reduction in treated water production (>34% of design output) 1 B
<12 hours loss of treated water production 2 C
12 – 48 hours loss of treated water Production 4 D
One sites affected for > 4 days
2 – 7 days loss of treated water production 8 E
>7 days loss of treated water production 16

8. Consequence and Likelihood Categories to Generate Risk Scores
Risk Table (Matrix)
Consequence and Likelihood Categories to Generate Risk Scores
Likelihood
Consequences
Severity A B C D E
Level
Score
(1)
(2)
(4)
(8)
(16) 1 2 4 8 16 32 3
(3) 6 12 24 48 64 5
(5) 10 20 40 80
Risk Score
˂ 6
6-16
˃ 16
Colour
Green
Amber
Red
Risk Rating
Minor
Major
Significant

9. Results of Risk Assessment
Summary of Risks to Al Ghubrah Desalination Plant
Item
Hazard
Hazardous Event
Before Control
After Control L C
Risk
Sea Water Quality
Feed Water Quality
Loss of Production
Harmful Algal Blooms 3 16 48 8 24
Jellyfish 2 32 4
Accidental Oil Spills at Sea 12
Operational Oil Spills at Sea
Re-circulation causing increased salinity
Excessive seawater temperature 1
Main Treatment Process
MSF Units
Structural Failure of Main Process Unit
Power Failure Multiple Units (steam/electricity)
Power Failure Single unit (steam/electricity) 5
Loss of Process Performance due to Scaling and Fouling
CO2 Plant
Structural Failure
Mechanical and Electrical Failure
Process Performance Failure
Chlorine Dosing 64

10. Results of Risk Assessment
Summary of Risks to Great Muscat Water Supply System
Hazard
Consequence
Before Control
After Control L C
Risk
Transmission Mains
Burst in main from Barka PS to Seeb Res
Loss of supply to Seeb 4 16 64 8 32
Burst in main from Al Ghubrah to Qurm, Wattaya,
Loss of supply to much of eastern Greater Muscat
Ruwi, Muscat, Mumtaz Res and Al Amirat PS (1000mm)
Loss of supply to part of eastern Greater Muscat 5 80 2 10
Ruwi, Muscat, Mumtaz Res and Al Amirat PS (600mm)
Burst in main from Al Ghubrah to Bausher Wilayat (Waver, Airport, Ghala, Bousher Res)
Pumping stations
Pump failure - Barka to Seeb PS
Partial loss of supply to Seeb
Loss of power - Barka to Seeb PS 1
Failure of control systems - Barka to Seeb PS
Pump failure - Ghubrah PS
Partial loss of supply to Eastern Gt. Muscat
Loss of power - Ghubrah PS
Loss of supply to Eastern Gt Muscat 40
Failure of control systems - Ghubrah PS
Loss of Supply from Desalination Plant
Loss of Supply from Ghubrah DP
< 12 hours partial reduction in treated water production (>34% of design output)
<12 hours loss of treated water production
12 – 48 hours loss of treated water production
2 – 7 days loss of treated water production
>7 days loss of treated water production 3 48 24

11. Interpretation of Risk Analysis Tables
Number of Severe Risks to Water Supply Utilities
Utility
Stage
Number with Severe Risk
Before mitigation
After mitigation
Al Gubrah Desalination Plant
Sea Water quality 5 4
Main Treatment process 1
Side wide risk 3
Total 17
Great Muscat Water Supply System
Transmission Main
Pumping Stations 6
Loss of supply from Desalination Plant 2 13 8

12. Evaluation of Resilience
Translation of Risk Score to Level of Resilience
Risk Score
Level of Resilience (score)
Resilience Ranking
1-5 4
very high
6-15 3
High
16 -32 2
Moderate
> 32 1
Low
4 Very high resilience: The risks to the system are very low.
3 High resilience: The risks to the system are acceptable.
2 Moderate resilience: The risks to the system are major.
1 Low resilience: The risks to the system are significant or extreme.

13. The Level of Resilience for Great Muscat Water Supply System
Hazard
Consequence
Before Control
After Control
Risk
Resilience Score
Transmission Mains
Burst in main from Barka PS to Seeb Res
Loss of supply to Seeb 64 1 32 2
Burst in main from Al Ghubrah to Qurm, Wattaya,
Loss of supply to much of eastern Greater Muscat
Ruwi, Muscat, Mumtaz Res and Al Amirat PS (1000mm)
Loss of supply to part of eastern Greater Muscat 80 10 3
Ruwi, Muscat, Mumtaz Res and Al Amirat PS (600mm)
Burst in main from Al Ghubrah to Bausher Wilayat (Waver, Airport, Ghala, Bousher Res)
Overall Transmission Mains Resilience Score
1.0 (low)
2.3 (moderate)
Pumping Stations
Pump failure - Barka to Seeb PS
Partial loss of supply to Seeb 16
Loss of power - Barka to Seeb PS 5 4
Failure of control systems - Barka to Seeb PS 8
Pump failure - Ghubrah PS
Partial loss of supply to Eastern Gt. Muscat
Loss of power - Ghubrah PS
Loss of supply to Eastern Gt Muscat 40
Failure of control systems - Ghubrah PS
Overall Pumping Stations Resilience Score
Loss of Supply from Desalination Plant
Loss of Supply from Ghubrah DP
< 12 hours partial reduction in treated water production (>34% of design output)
<12 hours loss of treated water production
12 – 48 hours loss of treated water production
2 – 7 days loss of treated water production
>7 days loss of treated water production 48 24
Overall Loss of Supply from Desalination Plant Resilience Score
1.8 (moderate)
2.6 (high)

14. The Average Resilience Scores to Water Supply Utilities
Utility
Stage
The Average Resilience Score
Before Control
After Control
Al Gubrah Desalina- tion Plant
Sea Water quality
2.3
2.7
Main Treatment process
2.2
2.8
Side wide risk
2.1
2.6
Great Muscat Water Supply System
Transmission Main
1.0
Pumping Stations
Loss of supply from Desalination Plant
1.8

15. Discussion of Research Findings
It was found that the risks to the main treatment processes of desalination plants can be controlled but the risk due to feed water quality might remain high even after implementing mitigation measures because of oil contamination and harmful algal blooms.
The risks associated with the transmission mains and pumping stations are worse compared to those associated with the loss of supply from the desalination plant. The analysis showed that the most severe risks are those associated with pipe rather than pump failure.
The research has shown that the resilience of the desalination plants is currently higher than the water supply systems, and the resilience of the transmission mains and pumping station is very low. By implementing mitigation measures the resilience of the water utilities could reach 70%.

16. Conclusions
The financial impact posed by Non-Revenue Water (NRW) was found to be 32% of the total revenue budget. This is high in comparison with international standards.
The results emphasize that exceptional events can have a severe impact on water system management. Risk associated with exceptional event is very difficult to assess.
The study concluded that resilience of parts of the water system in Oman is low and mitigation measures are certainly needed.
The risk assessment process has contributed to an advancement of knowledge which can be applied to water networks in the Middle East and other arid countries.

17. TIME FOR QUESTIONS