易县紫荆关五一渠的4座梯级水电站建站十几年来，每年冬季皆因冰害而停止发电。1994年在渠首修建了橡胶坝蓄冰库，并增建了冬季引水专用渠道。工程投入运行后，取得了1994年和1995年两个冬季连续发电2238万kW·h、售电收入已超过工程投资的显著成效． Yi County Bauhinia Guan Wuyi Drainage 4 cascade hydropower station construction site more than 10 years, every winter because of ice damage and stop generating electricity. In 1994, a rubber dam was built at the head of the canal, and a special channel for water diversion in winter was added. After the project was put into operation, it achieved remarkable results of 22.38 million kW · h of continuous power generation in two winter seasons in 1994 and 1995, which had surpassed the investment in electricity sales.