Eilidh Johnston, Sepa’s senior manager in water industry and rural economy, said a number of rivers remained under “sustained pressure”.
“Approaching significant scarcity for the third time this year in some areas highlights the vulnerability of eastern Scotland’s water environment,” she said.
“We understand that after such a long period the message may feel repetitive, and it’s easy to assume that rainfall will arrive in time to ease the pressure as it has before. But there’s no guarantee that will happen this time.”
Ironically, the warning by Sepa was issued just hours before heavy downpours caused flooding in Dundee and mudslides in Aberdeenshire.
The Met Office had issued a yellow weather warning for thunderstorms.
However, Sepa says the ground is often so dry that rainfall is running off rather than soaking into the ground.