Pre-monsoon checklist for flood warning systems
A link-by-link readiness check for the district and state teams who own a flood warning chain, from contact lists and danger levels to alert templates and last year's lessons.
Every flood season tests a warning chain all the way from the river gauge to the last household. Many of the failures that show up in July are set up in April: a contact list that still carries a transferred officer's number, a danger level that nobody revisited after a record flood, a data feed that quietly stopped reaching the control room. This pre-monsoon checklist is for the district and state teams who own a flood warning system and want to find those gaps while there is still time to fix them.
What is flood preparedness for a warning system?
Flood preparedness is the work done before a flood so that people and institutions can act in time when a warning comes. For a warning system, it means every link has been checked, from observation and forecasting to the message, the channel and the response, and the people at each link know their part.
The checklist on multi-hazard early warning systems published by WMO in 2018 groups these links into four elements: disaster risk knowledge; detection, monitoring, analysis and forecasting; warning dissemination and communication; and preparedness and response capabilities [1]. A chain is only as strong as its weakest link, so a pre-monsoon review should touch all four, not just the instruments.
In India the framework already exists. NDMA's Guidelines on Management of Floods (January 2008) call for preparedness to be reviewed in April/May every year, with corrective measures before the monsoon, and for a post-monsoon review in November/December that sets the action plan for the next season [2]. The Central Water Commission (CWC) SOP for flood forecasting lists the preparedness tasks to complete before the flood season at site, division, region and headquarters level [3]. State and district checklists, such as the one the Assam State Disaster Management Authority issued to Deputy Commissioners, turn this into dated tasks [4].
When should pre-monsoon preparedness be finished?
It should be finished before your control room goes live for the season. CWC's divisional flood control rooms open from 1 May in the North-East and Jammu & Kashmir, and from 1 June in the rest of India. They stay open until 31 October in regions served by the south-west monsoon and until 31 December in regions served by the north-east monsoon. They may open earlier if IMD forecasts pre-monsoon rain [3]. CWC's responsibility matrix sets preparedness and contact-list updates "by 30th April or 31st May" [3]. Assam's checklist asks Deputy Commissioners to hold the first Sub-Divisional Relief Committee meeting by 15 February, and to run a 24×7 flood control room through the notified season of 15 May to 15 October [4].
Working back from these dates gives a simple rhythm: audit in February and March, fix and test in April, sign off in May. The after-action review of last season should already be done. If it is not, start there.
The checklist
The table follows the warning chain from people to river to message and back. It deliberately stays at the level of the system. For the field work at each station, use our post-monsoon maintenance checklist for river monitoring stations.
| Area | What to check | Done when | Basis |
|---|---|---|---|
| Roles and authority | A named officer for each step: observing, forecasting, approving a warning, issuing it, acting on it. A nodal officer for the flood control room, a duty roster, and who approves a public alert at night and on holidays | Roster and delegation order signed and circulated | [1][4] |
| Contact lists | Officers, user agencies, upstream stations, dam operators, block and village functionaries, repair vendors. Mobile numbers and e-mail addresses entered wherever forecasts are sent from | Every entry verified by a call or message this season | [3][4][5] |
| Thresholds | Warning, danger and highest flood levels (HFL) at each forecast and monitoring point. HFL raised where last season exceeded it; new stations set up before the season; reviewed with users | Reviewed values in the forecasting system, the SOP and the alert templates | [3][5] |
| Stations and telemetry | Every station reporting at its scheduled interval after its maintenance visit | No station silent in the week before sign-off | [3] |
| Data to the control room | Readings arrive on time with correct time stamps; dashboards, bulletins and backups work; feeds from CWC, dams and neighbouring districts are received | One reading followed from gauge to bulletin | [1][3] |
| Alert templates and languages | Pre-written messages for each level, in the local languages, saying what is expected, where and what to do, plus an "all clear" | Templates approved and within reach of the duty officer | [1] |
| Channels | SMS lists, the state's Common Alerting Protocol (CAP) route, sirens, public address, radio, messaging groups, village functionaries; a backup for each | A test message confirmed at the far end of every channel | [1][3] |
| Sirens | Each siren sounded and heard | Test logged | [1] |
| Drills | A flood drill on the calendar with the agencies who must act | Date fixed and notified | [1][2] |
| Power and spares | Control room backup power and fuel, spare handsets, recharged SIMs, spare sensors and batteries, vendor contacts | Stock list checked against last season's failures | [1][3] |
| Inter-agency and upstream data | Coordination meetings with CWC, IMD, dam operators and neighbouring districts and states; sharing of real-time reservoir data | Minutes with named contacts and agreed data flows | [2][3] |
| Last year's lessons | Late or missed warnings, false alarms, stations that dropped out, messages that confused people | Each action closed, or carried forward with an owner | [1][2] |
Five items that need more than a tick
Thresholds
The warning level is the river stage at which CWC starts issuing level forecasts for a station. It is usually 1 m below the station's danger level, but depends on the threat at each location, and it is fixed in consultation with the state government [2][3]. CWC's alert categories then follow from three levels: yellow (above normal) between warning and danger level, orange (severe) between danger level and HFL, and red (extreme) above the HFL [3]. If the HFL changes, the line between orange and red moves with it.
An illustrative example: a station has a danger level of 120.00 m and a recorded HFL of 121.10 m, and last season's peak reached 121.35 m. The new HFL is 121.35 m, so a stage of 121.20 m, "extreme" last year, is now "severe". If the forecasting system is updated but the district's alert templates and siren triggers are not, the same chain will grade one flood two ways. Before the season, CWC asks for the warning level, danger level and HFL of every station to be entered in its data system and, where needed, reviewed with the users [5]. Check that every copy matches. If a gauge has been moved or re-levelled, confirm the levels refer to the same datum (see gauge zero, datum and benchmarks).
Data flow, end to end
Every station can be healthy while the duty officer still sees nothing. The WMO checklist asks for continuous monitoring for data gaps and connection problems, backup systems, and regular system-wide tests [1]. A practical test is a "paper flood": feed one station a simulated rising stage through warning and danger level, and follow it to the dashboard, the bulletin and the draft messages. Where data gets lost on the way is covered in from sensor to screen.
Messages and channels
Warnings should be clear, consistent, linked to actions and tailored to different groups, and people should be told when the threat has ended [1]. Writing these messages in May, in each language, is far easier than at 2 a.m. in July. On channels, CWC's SOP records that CAP alerts, generated through an application developed by C-DOT with NDMA, began as a pilot in Tamil Nadu in 2020 and went pan-India from 2022. The alerts go first to SDMAs, who turn them into warnings the public can understand [3]. Confirm that your state's route is live and that you know who presses the button. For choosing and combining channels, see early warning dissemination: sirens, SMS and CAP.
Upstream and neighbours
Floods do not stop at district boundaries. CWC's divisions attend district coordination meetings and coordinate with the neighbouring countries that supply hydrological data [3], and NDMA calls for reservoirs to share real-time data among basin states during the monsoon [2]. Know whose data you depend on, how it reaches you, and whom to call when it stops.
Last year's lessons
NDMA builds the post-monsoon review into the annual cycle [2], and the WMO checklist asks for lessons from past events to be fed back into plans [1]. Take the review's action list and mark each item closed, or carried forward with an owner and a date.
Key points
- A pre-monsoon review covers the whole chain: people, thresholds, data, messages, channels and response, not only the stations.
- Finish before your control room opens. For CWC that is 1 May in the North-East and Jammu & Kashmir and 1 June elsewhere.
- Re-check warning level, danger level and HFL after every season, and make sure every copy of them matches.
- Test the chain end to end with a simulated rise, and confirm that messages arrive at the far end of every channel.
- Close out last year's action list before starting new work.
Where ClimMaTech fits
At ClimMaTech we build the sensing and alerting parts of this chain: upstream radar and camera stations that measure water level and surface velocity, village sirens and phone alerts, with every live alert approved by an authorised operator. Our flood warning page describes how they fit together. Rakshak is a multi-hazard warning siren with a built-in library of 15–20 user-selectable siren tones and voice messages. Flood warning is its lead use, and the same siren can sound warnings for other disasters and for civil defence (air-raid) alerts, and broadcast voice announcements.
References
- World Meteorological Organization (for the International Network for Multi-hazard Early Warning Systems), Multi-hazard Early Warning Systems: A Checklist, WMO, 2018. undrr.org
- National Disaster Management Authority, National Disaster Management Guidelines: Management of Floods, Government of India, January 2008. ndma.gov.in
- Central Water Commission, Standard Operating Procedure for Flood Forecasting, Ministry of Jal Shakti, Government of India, April 2025. cwc.gov.in
- Assam State Disaster Management Authority, Check list for flood preparedness by Deputy Commissioner, Government of Assam, 2017 (copy hosted by the Cachar district administration). cachar.assam.gov.in
- Central Water Commission, Flood Forecast Monitoring Directorate, Preparedness for flood forecasting services for year 2024 and data/information requirement at Head Quarters, letter dated 8 March 2024. cwc.gov.in