The Water Department will begin its fall hydrant flushing program on the evening of Sept. 15, in the area of the Reeves Hill water storage tanks on Old Connecticut Path East. Residents can check the public works page on the town’s website, www.wayland.ma.us, for an updated list of streets that may be affected by the flushing. Officials say it will take about six weeks to flush the water system, with the work conducted between 10 p.m. and 6 a.m. Sundays through Fridays. Residents are asked to minimize water use during this time, and to check the water before washing clothes to avoid discoloration. Some customers will experience rusty or black water caused by naturally occurring iron and manganese being disturbed by the flushing process, officials said.