When teleporting to new chunks you see random blocks of flowing water generate around you which disappear when the chunks fully load.
MC-139054
Flowing water is visible on random blocks before chunks generate
Resolved
Duplicate
0
Nixinova
(Unassigned)
Unconfirmed
chunk-generation, chunk-loading, water, world-generation
Minecraft 18w45a
Retrieved
This bug is different from MC-137731 as I'm not inside any blocks and MC-137731 also doesn't mention random water or anything.