The Authority advises that severe storms, resulting from Hurricane Fiona have brought significant rainfall to the watershed.
As of this morning rainfall amounts have ranged from 50 to 100 mm since Sunday, with the heaviest amounts concentrated along the shoreline.
They expect the severe storms to continue through the day bringing 20 to 35 mm of rain, with the heaviest amounts along the shoreline.
The water levels in streams have already risen by over 30 cm in the past 24 hours, and soil is saturated which means current rain will end up as runoff.
The water safety statement is in effect until 10 pm on Thursday.