Project story
Inside the Terai EWS rollout — 62 stations in nine months
Photos from the field
When DHM commissioned IES to design and install a 62-station early warning network across Province 2, the brief was simple: cover the flood-prone Terai belt before monsoon. The reality, as always, was more complicated.
Site selection alone took six weeks. Each candidate location was assessed for flood exposure, community accessibility, and — critically — a reliable line of sight for radio telemetry back to the district hub. Of the 90 sites originally scoped, 62 passed every criterion.
Our field engineers standardised on a solar-powered sensor package built to survive the Terai's climate extremes. The final station specification included:
- Solar-powered water-level sensor with battery backup rated for 10 days without sun
- Tipping-bucket rainfall gauge, calibrated to local monsoon intensity
- Dual-path GSM / radio telemetry — redundancy if the mobile network fails during a flood
- Tamper-resistant, flood-rated enclosure rated to IP66
- Local siren and light alarm, triggered independently of the central system
Getting the hardware right
Our field engineers standardised on a solar-powered sensor package built to survive the Terai's climate extremes. The final station specification included:
- Solar-powered water-level sensor with battery backup rated for 10 days without sun
- Tipping-bucket rainfall gauge, calibrated to local monsoon intensity
- Dual-path GSM / radio telemetry — redundancy if the mobile network fails during a flood
- Tamper-resistant, flood-rated enclosure rated to IP66
- Local siren and light alarm, triggered independently of the central system
"The community handover mattered as much as the engineering. A station nobody trusts is a station nobody evacuates for."
85
zfdgxfcnb
85
zdgcbc
Community handover
Every station was handed over with a trained local caretaker, a laminated response protocol in Nepali, and a direct line to the district disaster management committee. This is the layer that determines whether an early warning actually becomes early action.
The full network went live ahead of the 2025 monsoon season, with performance data now feeding into DHM's national flood forecasting dashboard.
More from
Insights & impact
Case study
Tsho Rolpa glacial lake — risk assessment to mitigation design
A detailed look at the scientific study, modelling approach and recommendations delivered to DHM for Nepal's highest-risk glacial lake.
Nov 2024 · Research & Consulting
Event
IES at the Nepal DRR & Climate Resilience Symposium 2025
Our hydrology and EWS teams presented findings on multi-hazard early warning design to government and donor partners.
22 Jan 2025 · Kathmandu
R&D finding
Improving sediment-flow calibration in mountain river EWS
Our in-house research lab's latest findings on refining sediment monitoring thresholds for more reliable flood forecasting.
Dec 2024 · Research Lab
Project story
Insight 5
Project story
Insight 6
Project story
Insight 7