Follow the rivers.
Trace five rivers across the district map and explore places along their mapped lines.
NATURAL EARTH / GENERALISED CENTRELINES
Choose a river.
The map shows simplified lines from a global dataset. Select a name to bring its line forward and see the districts its mapped geometry touches.
These are geometric intersections with simplified 2021 boundaries, not an official list of river districts. This is neither a complete river network nor a flood warning.
DISTRICTS / MAPPED INTERSECTIONS
Son
The mapped line touches these district shapes. Select a district to explore its people and places.
A VIEW OF THE GANDAK
Along the riverbank.
White grasses along the Gandak River in Bihar.
Photograph: Shivam Kunal. River identified by the photographer; precise location and date not supplied.HISTORICAL FLOOD RECORDS
When rivers spread beyond their banks.
For 9–23 July 2020, the National Remote Sensing Centre produced a preliminary cumulative map highlighting inundation in 23 Bihar districts, using satellite passes on selected dates. The centre cautioned that low-lying rainwater could be included and that it had not verified the map on the ground.
Read NRSC’s July 2020 map and limitations ↗
Bihar’s Flood Management Information System lists inundation maps under years 2021 through 2026. The centre describes their flood-water extents as derived from RADARSAT imagery processed by NRSC. The original service carries the individual map dates and coverage.
Open the flood centre’s inundation map index ↗ · Explore historical flood layers on ISRO Bhuvan ↗
These are links to historical source services, not layers hosted or independently verified by Bihar Unpacked. Past flood extent is not a current flood warning.
RIVERS AND EMBANKMENTS
Protection, sediment and risk.
Bihar’s flood centre describes northern rivers carrying sediment onto the plains. The centre credits Kosi embankments with reducing flood severity, while also describing the risk of breaches and backwater when the Ganga is in flood. In 2008 a Kosi embankment breached at Kusaha in Nepal; the flood affected places on both sides of the border.
These observations do not mean that every flood has the same cause or that a historic footprint is a forecast. A bridge closure can cause serious disruption, but the retained road snapshots here are not a complete current road network and cannot establish which alternative crossings remain open.
Bihar flood centre: river-basin descriptions ↗ · World Bank: Kosi recovery ↗ · Read the river question ↗
Reading the map
Rivers change course, and a small-scale centreline can omit channels or be displaced from the ground. The lines here are a starting point for exploration, not surveyed boundaries, current water levels or flood exposure. Flood footprints and warnings require separate dated sources.
Explore the 2024 groundwater assessment ↗ · Compare rainfall and temperature ↗ · Natural Earth source ↗ · District boundary source ↗ · Rain and rivers ↗