Howard Snowden, managing director of Jersey Water, said there was a long way to go as the islands reservoirs were still 60% empty.

BBC: Jersey water stocks improved by heavy rain

"Rivers, streams and lakes are measurably cleaner than they were before the Clean Water Act, but we still have a long way to go, " said Bob Irvin of the World Wildlife Fund, the world's largest privately funded conservation organization.

CNN: Challenges ahead for a changing Earth