The 6,300 km long Yangtze River in China was facing a reduction of wetlands areas and flood retention capacity. In 2002, the World Wide Fund for Nature (WWF) initiated a programme to reconnect lakes in Hubei
Province to the Yangtze River through opening the sluice gates and facilitating sustainable lake
management. These wetlands can store floodwaters and therefore reducing vulnerability to flooding in the central Yangtze region.
The Yangtze River is 6,300 km long and home to more than 400 million people. The river basin drains a 1,800,000 km basin and has extensive lakes and floodplains of significant environmental and retention importance. In the summer, the basin experiences floods, especially in the central Yangtze. Extensive development in the last fifty years has converted 1,066 lakes 757 coverings along 2,150 km2 into polders, reducing wetland areas by 80% and flood retention capacity by 75%.
Since 1991 there have been several highly damaging flood events that have killed thousands of people and cost billions of dollars. The Lakes and basin have also become extremely polluted, in particular because of the application of fertilizer to aquaculture pens. The loss of connection to the Yangtze River prevents diluting flows and the migration of fish. Drought in recent years has increased water pollution, and climate change and increased temperatures are expected to worsen eutrophication
In 2002, the World Wide Fund for Nature (WWF) initiated a programme of sustainable lake management to reconnect the lakes in the Hubai Province to the Yangtze River through opening the sluice gates. The programme focused on three lakes: Zhangdu (40 km2), Hong (348 km2 and Tian’e Zhou (20 km2). Given the poverty of the populations in the region, finding alternative and sustainable livelihoods and sources of income was important. The average income of residents in the area was just USD 1.34 per day. WWF formed partnerships with government agencies and others to explore options for more sustainable river basin management.
Since 2004-2005 in Hubei Province, the sluice gates at lakes Zhengdu, Hong and Tien’e Zhou have been seasonally re-opened and illegal and uneconomic aquaculture facilities and other infrastructure removed or modified. Now these 448 km2 wetlands can store up to 285 Mm3 of floodwaters, reducing vulnerability to flooding in the central Yangtze region.
The forced ending or removal of illegal or unsustainable aquaculture have reduced pollution levels. In Lake Hong, pollution fell from national pollution level IV (fit for agricultural use only) to II (drinkable) on China’s five-point scale.
Of immediate benefit for the Yangtze River Basin was the increase in wild fisheries species diversity and populations. Within six months of reconnection of Zhangdu Lake, the catch increased by 17 per cent and nine fish species returned to the lake. Similarly the catch increased by 15 per cent in Baidang Lake. Development of certified eco-fish farming by 412 households increased income of fishers by 20 to 30 per cent on average. Similarly, the income from fisheries at the Yangcai Hu area of Hong Lake increased by 25 per cent after restoration. Bamboo farming has also been implemented as a measure to stabilize steeper lands near the lakes. Twelve migratory fish species have now returned to the lakes. At Zhangdu Lake, 60 km2 of lake and marshland were designated as a nature reserve by the Wuhan Municipal Government. To strengthen the effectiveness of wetland conservation efforts in the Yangtze River basin, a Nature Reserve Network was established to link 17 nature reserves (12 later designated) covering 4,500 km2. As a result of these benefits, in 2006 the Hubei Provincial Government adopted a wetlands conservation master plan and allocated resources to protect 4,500 km2 by 2010.
The success of these adaptations was replicated in other areas of the Yangtze and China.
Combined using a green and grey approach. The implementation of sluice gates allowed for seasonal opening and reconnection of regional lakes to the Yangtze River. Reconnecting the water flows required the removal of some aquaculture businesses, but brought up overall levels of fisheries in the river basin with significantly more migratory species returning to the area, which in turn boosted incomes of local fishers. The environmental effects also significantly improved water quality which was extremely polluted prior to the facilitation of water flow via connecting the lakes to the tributaries.