Management requires measurement: Reducing flood damage by
improving response time
Soumya Balasubramanya, Yann Chemin, Lahiru Wijesinghe, Farah
Ahmed, Mohamed Aheeyar, David Wiberg

Pilot project in Nachchaduwa
• Objective: To assist the Irrigation Department
of Anuradhapura in reducing damages from
flooding.
• Challenge: managing competing constraints
– Tank needs to be maintained at FSL for irrigation
– Many flashfloods in recent times
– Rainfall information available once a day, as daily
average

Pilot project aims
1. Construct IWMI-developed weather stations
2. Install weather stations to address ID’s information
needs
3. Document costs of assembling, installing, activating,
using, and maintaining mobile stations
4. Understand the cost-effectiveness of using such mobile
stations
1. Highlight opportunities and constraints for scaling this
solution to the entire country

1. Construct IWMI-developed weather stations
http://www.iwmi.cgiar.org/resources/mobile-
weather-stations/

2. Install weather stations to address ID’s needs
• Programmed to send SMS when rainfall
>10mm/hr; requested by ID-Nachchaduwa

2. Install weather stations to address ID’s needs
• Weather stations installed in
upper catchment of reservoir
• Improves response time to
calculate peak runoff
• Can calculate expected inflow
into reservoir; create storage
space to accommodate runoff
• Can reduce damages caused
from reservoir spilling

3. Document costs of mobile stations
Price/Unit (USD) Unit Cost
F08079 Serial Log Chip Open Source Data Logger Module* 9.50 1 9.50
JST SH Jumper 6 Wire (GPS)* 2.95 1 2.95
GPS receiver* 39.95 1 39.95
Weather meter [1] 76.95 1 76.95
Weather Shield for Arduino* 39.95 1 39.95
RJ11 (x2), 6 pin connector for Weather Shield* 1.25 1 1.25
Arduino stackable header kit - R3* 1.50 1 1.50
8 Gb Memory Card* 6.85 1 6.85
Arduino Mega - Circuit Boards* 8.22 1 8.22
5A Solar Controllor* 9.59 1 9.59
Solar Panels* 27.39 1 27.39
Motorbike Battery* 26.70 1 26.70
Parts* 20.54 1 20.54
Steel stand structure* 47.93 1 47.93
GSM Module* 30.00 1 30.00
Total [2] 349.25 1 349.25
[1] To be replaced every three years in SL
[2] Entire weather station to be replaced every 10 years (recommended)
Equipment

4. Understand cost-effectiveness
• Conservative estimate; assume intense rainfall occurs
once every 5 years; assume weather stations replaced
every 3 years
• Post-disaster rehabilitation expenditures by government
(financial value of damages)
• Run scenarios—with reduction of 10% in post-disaster
expenditures due to better management CER =2
• If economic value of damages is considered; then even
more cost-effective

Next steps
• Monitor hardware/software to ensure
systems are functioning before NE
monsoon commences
• Follow up with ID-Nachchaduwa to
understand how text messages were
used

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Next steps

Thank you!