These are vectorized shapefiles of permanent water reservoirs based on Global Surface Water (GSW) raster images for India.
The Global Surface Water Project provides several raster datasets, one of which contains information about the seasonality of water. Each pixel receives a value between 0 and 12 indicating the number of months that water was present from January 2018 to December 2018.
Details about data: https://storage.cloud.google.com/global-surface-water/downloads_ancillary/DataUsersGuidev2018.pdf
https://storage.googleapis.com/global-surface-water/downloads2/seasonality/seasonality_70E_10N_v1_1.tif https://storage.googleapis.com/global-surface-water/downloads2/seasonality/seasonality_70E_20N_v1_1.tif https://storage.googleapis.com/global-surface-water/downloads2/seasonality/seasonality_70E_30N_v1_1.tif https://storage.googleapis.com/global-surface-water/downloads2/seasonality/seasonality_80E_20N_v1_1.tif https://storage.googleapis.com/global-surface-water/downloads2/seasonality/seasonality_80E_30N_v1_1.tif
gdal_merge.py -init "255" -o season_merge.tif seasonality*
(seasonality is 12, i.e. water year-round)
gdal_calc.py -A season_merge.tif --outfile=permWater.tif --calc="A==12" --NoDataValue=0
mkdir permWater
gdal_polygonize.py permWater.tif permWater/permWater.shp -b 1 -f "ESRI Shapefile" permanent water
Manually removed water buffer around India and islands.