TheRiver Tib is a minor tributary of theRiver Medlock inManchester,England. It has beenculverted along its entire length since about 1783[1] and now runs beneathManchester city centre. Tib Street (53°29′01″N2°14′05″W / 53.4837°N 2.2348°W /53.4837; -2.2348) and Tib Lane are named after the watercourse.
During theRoman period, the Tib marked the boundary of thevicus or settlement ofMamucium; the river continued to mark Manchester's boundary until medieval times, as well as providing drinking water.[2] A notion concerning the Tib's name, coined by Geoffrey Ashworth in his bookThe Lost Rivers of Manchester, is that the river was given its name by homesick Roman soldiers after theRiver Tiber, but with the word shortened to reflect the size difference between the two rivers.[3] Alternatively, the name may derive from theCeltic word for "watercourse".[2]
The river's source is a spring inMiles Platting (53°29′36″N2°13′08″W / 53.493251°N 2.218797°W /53.493251; -2.218797), from where it flows underneath Oldham Road and the eponymous Tib Street to reach the city centre. After flowing underneath West Mosley Street, the Tib crosses Princess Street to flow underneath theManchester Town Hall Extension, theCentral Library and theMidland Hotel's dining room, before joining the Medlock at Gaythorn (now First Street,53°28′23″N2°14′52″W / 53.473164°N 2.247663°W /53.473164; -2.247663), close toDeansgate railway station.
Parts of theRochdale Canal around Lock 89 (Tib Lock) can be emptied into the River Tib by opening a small, original wooden trap door installed during construction.[4] Lock 89 was one of the bottom nine locks opened in 1800.[5]