Environmental flow allocation for the Zhangxi River, China

摘要

Ningbo city, located in Zhejiang province of China, is a rapidly growing residential andudindustrial centre, with a current population of 4 million. Its development has required a majorudwater supply expansion programme aimed at providing 400,000 m3 of water per day toudNingbo from the upper reaches of the Zhangxi River by means of a cascade of reservoirs. Audloan to support the work was agreed by the World Bank in 2005. Water resourcesudmanagement is achieved through operation of two major reservoirs, Jiaokou (completed inud1980, available storage capacity 75 million m3) and Zhougongzhai (completed in 2006,udavailable storage capacity 93 million m3). Water is released from the reservoirs, via turbines toudgenerate hydropower, to provide for the needs of local industry, irrigated agriculture andudpublic supply along the lower reaches of the River and to maintain the river ecosystem.udSurveys of local residents along the Zhangxi River shows that it plays a very important role inudthe aspects of life, social activity, culture and leisure. Analysis of ecological monitoring dataudhas demonstrated the diverse nature of fish, plants and invertebrates within the river. Someudelements of the ecosystem have a high local economic value to local people. However, theudRiver does not have abundant ecological resources.udThis paper reports environmental flow needed to support key species in the river ecosystemudquantified during an initial research project. It recommends a water allocation plan to meet theudvarious water requirements of the ecosystem and local society in addition to Ningbo city.