Amplified by the driest March since 1953, rivers and ponds are drying up at a time they should be increasing in volume.
This is causing fish, amphibians and other creatures to die in great numbers.
While some fish have been gathered from a handful of dwindling streams and ponds for storage until the rains return, officials say they lack the resources to conduct such rescues on a large scale.
Wildlife experts say species such as water voles, dragonflies and wading birds will also be affected by the parched conditions.
Outbreaks of wildfires are also being feared if the summer becomes as hot as during recent years.
Meteorologists warn that the drought is likely to persist until at least the end of the year.