Pollution caused by large-scale flower farming is wrecking havoc on Kenyaâ€™s Lake Naivasha, the only fresh water ecosystem in the eastern Rift Valley, according to experts.
â€œApart from the direct pollution from flower farms, the uncontrolled population growth of poor people in the Naivasha has been the main source of pollution,â€ Andrew Enniskillen, the chairman of Lake Naivasha Riparian Association, told reporters this week.
â€œThe number of people living within five kilometres of the lake has risen from 50,000 in 1980 to 250,000 this day,â€ he said, adding that job opportunities in the flower farms had attracted an increasing number of people to the town.
The falling water levels, pollution caused by agro chemicals, over-exploitation of fisheries as well as fuel leakage from the farm machinery are taking their toll on the only non-soda lake and its biodiversity.
â€œThis lake and its wetlands have been over used and polluted, mostly by chemicals from flower farms and this has affected its biodiversity,â€ said Stanely Mbugua, a fisherman who has depended on the lake since 1966.
Flower exports have become Kenyaâ€™s second major foreign exchange earner after tea and tourism, bringing more than $100m into the Kenyan economy each year.
Torrential rains in Kenya in the year 2000, washed huge amounts of chemicals into Lake Naivasha and the eutrophication of the lake, 80 kilometres northwest of Nairobi, killed â€œmillions of fish and other aquatic life,â€ according to an environmental researcher.
Fertiliser residue and other agro-chemicals have been trapped in the soil along the lakeâ€™s shores next to the flower farms, according to the Consultative Group on International Agricultural Research (CGIAR).
â€œEven birds â€” fish-eagles and kingfishers â€” that captured and ate the poisoned fish died at worst or have been affected,â€ a CGIAR researcher who asked not to be named told AFP.
Rodrick Kundu, a government fisheries officer, said the death of millions of fish in the year 2,000 coupled with over fishing had forced the government to slap a ban on fish harvesting for a year.
Mbugua, a former flower pruner, said some farms were still using banned chemicals, which have affected the health of farm workers and polluted the environment.
But flower farm managers beg to differ.
â€œWe have excellent water and sewage treatment facilities here.
We do not let chemicals into the lake whatsoever. We are very conscious of our farming techniques,â€ said James Kelmanson, the technical manager at the Dutch-owned Oserian Flowers, one of about 30 horticulture farms in Naivasha.
â€œWe understand that environmental conservation is the hallmark of this trade. If we mess, we are done,â€ he said.
Kelmanson said Oserian had developed a new way of fighting fungal diseases without resort to chemicals. Instead the company uses geothermal steam in the greenhouse to get rid of the diseases.
â€œThis method has reduced the use of chemicals by 25 percent,â€ Kelmanson explained.
Lake Naivasha is the key source of irrigation water for an extensive flower belt.
â€œToo much irrigation has reduced the water levels,â€ said farmer Joseph Kamau, who has lived near the lake for three decades.
Mbugua is pessimistic about the future of the lake.
â€œWe understand why nothing has been done. It is not an easy decision weighing between keeping the benefits from the lake and the benefits of the flowers.â€
Lake Naivasha being polluted by flower farmers and the poor