伦敦以西伯克郡的泰晤士河沿岸，经常暴雨成灾。为解除洪灾威胁，投资8300万英镑，修建一条长11．5km的分洪渠，以增加河流行洪能力。分洪渠断面为梯形，底宽30m，顶宽45m，高5m，边坡1：1．5。有些地方从景观考虑宽度大得多，在公路和铁路下面穿过时宽度较小。分洪设计流量为2 River Thames in West Berkshire, London, often torrential rains. To relieve the threat of flooding, invest 83 million pounds to build a 11.5km long flood diversion canal to increase river flood capacity. The section of the flood diversion canal is trapezoidal, the bottom width is 30m, the top width is 45m, the height is 5m and the slope is 1: 1.5. Some places are much wider in landscape and smaller in width when passing under roads and railroads. Flood diversion design flow is 2