The fairly steep-sided bowl in which Truro is located, along with high precipitation swelling the rivers and a spring tide in the River Fal, were major causes of flooding in 1988 which caused large amounts of damage to the city centre.
[3] Since then, flood defences have been constructed around the city,[3] including an emergency dam at New Mill on the River Kenwyn and a tidal barrier on the Truro River, to prevent future problems.
[5] The river is mentioned in the medieval Cornish language play Bewnans Ke (c. 1550), as the place from which the eponymous Saint Kea embarks for Rosené.
It uses the river's Cornish name Hildrech, which in modern spelling is Hyldreth.
[6] The river from the city to the village of Malpas, including Lambe Creek and Calenick Creek, form Malpas Estuary SSSI (Site of Special Scientific Interest).