bridge is the Furness line railway viaduct. The River Winster flows into the estuary from the north, just before the Kent enters Morecambe Bay, a vast area of intertidal mudflats and sands. The tidal range at the mouth of the river and the shape of the estuary result in a tidal bore occurring near Arnside, which is known as the Arnside Bore. It is usually visible on spring tides, when the tidal range exceeds , and is affected by wind direction and recent rainfall. South Lakeland District Council have installed a siren, which is sounded approximately 15 to 20 minutes before the bore is expected to reach Arnside, and again when it actually reaches Blackstone Point, a little further down the estuary. History The river has been used to provide water power over a long period. Around 1800, farms around Kentmere, in the upper reaches of the river, were bought by wealthy outsiders, and efforts were made to improve the land for agriculture. Fields were drained by land drains, and around 1840 the Wilsons, who lived at Kentmere Hall, drained Kentmere Tarn, in the hope that it would provide high quality farm land. This was not particularly successful, but had unexpected effects. The water-holding bogs which were drained had previously acted as a giant sponge, soaking up water and releasing it steadily into the river. The flows now fluctuated much more than before, to the detriment of the mills. In 1844, a scheme to build reservoirs to regulate the flow on the Kent and other rivers was promoted. A committee of ten mill owners plus the major of Kendal was formed, and asked the water engineer John Frederick Bateman to advise on the scheme. A bill was submitted to Parliament, and was signed by Queen Victoria on 21 July 1845. It authorised five reservoirs, but only that at Kentmere Head was built, with work completed in 1848. In order to pay for the work, and ongoing maintenance, mill owners who benefitted from the scheme were charged a rate, which was based on the amount of fall in levels through the mill site. The amount of power which could be extracted from a given flow is directly proportional to the fall, and this method of charging was agreed to be fair. Only those mills with an annual value of £50 or more were required to pay rates, while corn mills having