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Background
Context: Dar es Salaam and Morogoro, Tanzania
MCC Water Sector Project objectives:
• Increase water supply
• Improve water quality
Intermittent water supply leads to poor water quality and economic burden to obtain water
Household surveys are uncertain measures of access
Challenges in measuring water access through household surveys
Unreliability of recall questions
Different answers depending on phrasing of question
-> e.g. “Shortage” versus “Access”
Ubiquitous water storage tanks
What we really want to know is: (1) average hours of water service per day; and (2) number of outages.
Sensor solution: water pressure loggers on household taps
The sensor: Global Water Garden Hose Pressure Logger
• Connects to end of yard tap
• Logs pressure continuously for months on 2 9V batteries
• Download via USB to PC
The method:
• Rotate weekly among random subsample of surveyed households
• 7 weeks x 30 loggers
• Full-time installer in each city
Prior ExperienceMapping the walk for water in Ekiti, NigeriamWater with support of The World Bank Innovation Fund
Gender disaggregated household surveys about water access
+Linked to GPS sensor track data on time and distance to gather water
+Linked to water quality testing of sources
@mWaterCo
Data collection
Install Scan
7 days
Download Survey
Logger Update ->mWater cloud
Data file ->Dropbox
Data management
mWater Explorer App looks up pre-loaded with logger profiles by barcode scan
Geolocates and records household ID at key events:
• Install
• Uninstall
• Data download
Data analysis
Week 1 Continuous
Service
Week 2 Intermittent
Service
1.Import logger files as CSV
2.Installation location and date/time exported from mWater
3.R script to clip pressure data at install/uninstall times
4.Threshold for on/off
5.Calculate indicators
Diversity of service patternsWeek 1 Week 2Week 1 Week 3 Week 4
Lessons learned
Operations
•Some (dis)assembly required! …but you don’t need a plumber
•Protection from loss/theft -> Lockboxes needed ~30% of sites
•Replacement criteria need to be flexible
•Reliable daily internet access for real time monitoring -> Prevents mistakes from turning into data loss
Costs
•Sensors: $500 / unit
•Full-time staff member / 15 sensors (2 - 3 installs per day)
Next?
How could it be better?
•Cell phone data link + GPS for better inventory tracking
•In-line injection molded design -> less conspicuous
•Or… as a replacement for some bulk or household water meters
Potential uses
•Utility network monitoring to reduce non-revenue losses
•Output-based aid / performance-based contracting verification
•Post-2015 Sustainable Development Goals - monitoring water access and reliability
