Fears that rivers could become toxic to fish have been voiced by the Environment Agency after a dry April.
Algal blooms could make water poisonous to fish, otters and water voles, if dry weather continues in May, it said.
People have been asked to report any environmental incidents to the agency and to conserve water supplies.
A wet winter ended the drought across Kent, Surrey and Sussex, but the agency said Kent's 2mm rain in April was just 4% of the county's monthly average.
Biodiversity expert Adam Ingleby said: "Insects feed on flowers, birds feed on insects. As our climate changes, we are seeing these patterns shifting.
"At the moment wildlife seems to be keeping up with the changes but unseasonable weather could have dramatic effects on the food chain."
Bank holiday warnings
Environment Agency manager Harvey Bradshaw asked people to continue saving water even though supplies have improved.
Warnings also came from Southern Water on Thursday that gardeners should not forget to save water this bank holiday weekend.
Meyrick Gough, planning and strategy manager, said: "We have had lots of winter rain which has recharged our reservoirs and underground sources. However, it is important we all continue to do our bit."
He said customers saved enough water each day last summer to supply a city the size of Brighton.
Thames Water, Southern Water, Three Valleys Water and Sutton and East Surrey Water lifted their hosepipe bans in January, while South East Water removed its restrictions at the start of February.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©
~RS~q~RS~~RS~z~RS~06~RS~)