The distinctively shaped a href="https://en.wikipedia.org/wiki/Weir" target="_blank"weir/a, which is 460 feet (140 m) long, helps create a pool of water that can enter (via an adjacent valve house and flow meter) the a href="https://en.wikipedia.org/wiki/Llangollen_Canal" target="_blank"Llangollen Canal/a. The canal above a href="https://en.wikipedia.org/wiki/Pontcysyllte_Aqueduct" target="_blank"Pontcysyllte Aqueduct/a and the construction of the weir were authorised by an a href="https://en.wikipedia.org/wiki/Act_of_Parliament" target="_blank"Act of Parliament/a obtained in 1804 by the a href="https://en.wikipedia.org/wiki/Ellesmere_Canal" target="_blank"Ellesmere Canal/aCompany. The canal was a navigable feeder, which supplied water to the Ellesmere Canal beyond Pontcysyllte, and to the a href="https://en.wikipedia.org/wiki/Chester_Canal" target="_blank"Chester Canal/a, to which it connected near a href="https://en.wikipedia.org/wiki/Nantwich" target="_blank"Nantwich/a. a href="https://en.wikipedia.org/wiki/Thomas_Telford" target="_blank"Thomas Telford/a was the a href="https://en.wikipedia.org/wiki/Civil_engineer" target="_blank"civil engineer/a responsible for the design, and the canal and feeder were completed in 1808.a href="https://en.wikipedia.org/wiki/Horseshoe_Falls_(Wales)#cite_note-FOOTNOTEHadfield1985178-1" target="_blank"[1]/a