Hyacinth overgrowth ruins Ambarawa livelihood
Ressi Fadjar Himawanti, The Jakarta Post, Semarang
Thousands of farmers in the zone of Rawapening, Java's largest natural lake in Ambarawa district, Semarang regency, Central Java, have suffered considerable losses of income this year as the water is submerging hundreds of hectares of surrounding rice fields.
Water hyacinth, locally known as eceng gondok, has covered three fourths of the lake's surface, causing floods particularly during the rainy season. While normally a hectare of land cultivated by Surdi (45), a farmer in the district's Tambakbayan village, can produce seven tons of paddy, "Now even in the dry season the output has dropped to five tons," he said recently.
Another farmer, Trisno (51), complained about his decreasing harvests due to rat-infested fields. "It's hard to eradicate the rats because they are hidden under hyacinth leaves," said Trisno, also living near Rawapening, which includes eights villages in four districts.
Other farmers around the lake, like Zhugin (50) and Maarif (68), put fishing nets in the water basin. They told The Jakarta Post that their catch had decreased substantially in the last two years, from around 20 kilograms to only three kilograms daily. "Hyacinth has increased the lake's fish population but it is more difficult to catch under the leaves," said Maarif.
Semarang Regent Guritno meanwhile said out of Rawapening's total surface area of 2,670 hectares, more than 75 percent has been blanketed by water hyacinth, leaving only around 200 hectares open, thus posing a threat to the livelihood of 29 groups of 2,200 local farmers and fishermen.
Guritno also referred to the high rate of sedimentation as nine rivers emptying into the lake carried debris of erosion and deforestation besides other agricultural and household waste. A survey team has predicted that Rawapening will dry up within the next 10 to 15 years.
Guritno added that Rawapening's flow rate reached 65 million cubic meters and its stream provides water for 200,000 hectares of fields in the regencies of Semarang, Grobogan and Demak as well as the cities of Semarang and Salatiga. The same source also supplies energy for the Jelok hydro power plant with an installed capacity of 32,980 KW and the Timlo plant with 25,000 KW.
Joko Sutrisno, head of the provincial environment impact control agency, told The Jakarta Post amid a ceremony declaring the local community's hyacinth control drive at Bukit Cinta, Banyubiru, Semarang recently that this plant caused a high rate of lake water evaporation.
The average degree of evaporation is more than 10 percent of the lake's annual flow rate, according to Sutrisno, while the fast growth of hyacinth will result in shallowing and high content of organic materials, which make algae flourish and turn sediment into peat.
Peat utilization by a company, PT Dieng Jaya, on Dieng highland in Wobosobo for growing straw mushrooms has been discontinued, whereas dryland vegetable planting by farmers in Getasan, Bandungan and Salatiga has proceeded without conservation, leading to erosion in the wet season.
The rivers carrying pesticide residue from the vegetable planting area have raised the content of trace elements in Rawapening's sediments, which in turn causes eceng gondok to grow faster. The use of hyacinth leaves for handicraft products even speeds up the plant's vegetative regeneration.
Sutrisno disclosed that hyacinth on the lake surface had been cleared during the Dutch colonial administration in 1931, followed by further efforts in 1947 and 1952. The Central Java water resources management board (PSDA) has done the same on a routine basis, but the growth of this water plant remains beyond control.
As the largest water reservoir in Central Java, Sutrisno emphasized the necessity of conserving Rawapening. Apart from favorably affecting the climate for agriculture, the lake also serves to control floods from the upstream of Tuntang river. Unless curbed by the lake, Demak and Grobogan areas would be severely flooded.
Central Java Governor Mardiyanto said on the occasion the best way of overcoming the problem was to control eceng gondok because this plant, while harming the interests of farmers and fishermen, had favored craftsmen by increasing the value of their products.
He therefore indicated that for the handicraft industry, water hyacinth would be maintained so that its total eradication should be avoided.
Sutrisno suggested that the hyacinth area in Rawapening should be zoned to reserve several hectares for the industry but this portion retained should be controlled, while the rest must be eliminated so as not to harm agriculture and fishing.
Rawapening conservation has in fact been under Semarang regency's planning with a Rp 30.2 billion allocation for five years, comprising Rp 16.2 billion for hyacinth control and Rp 14 billion for nine-river dredging and reforestation of over 200 hectares.
The provincial PSDA provides Rp 700 million annually for Rawapening water control, and the United Nations Development Program (UNDP) has made available US$1.7 million or around Rp 170 billion through several non-government organizations engaged in lake conservation.
In 2003, the provincial administration has budgeted Rp 320 million for Rawapening conservation and the Semarang regency has also allocated Rp 600 million for the same purpose.
The various funds for the conservation of this vital lake, however, are not being utilized in an integrated fashion. That is also the case with the efforts undertaken by different stakeholders. Consequently, the lake community has not yet enjoyed any positive effect of the endeavor and much of the money is being wasted due to a lack of cooperation or coordination.