Lake Koka lies a few hundred miles south of Addis Abeba. It used to be idyllic.

Today however, it is so heavily polluted that the water glows a toxic green, most of the fish are dead and the thousands of people who have no choice but to drink the lake's water each day are left to deal with a range of problems from babies born with birth defects to chronic diarrhea.

When most think of Ethiopia, images of drought and famine spring to mind. What few realise is that the country is currently experiencing phenomenal economic growth.

This has come at a cost to the environment and to Ethiopia's poor who depend on it.