The Lavant may once have had its source north of Midhurst, with the increased drainage area possibly leading to size more akin to the River Rother; however, erosion and weathering over centuries have led to its current source and size. The Lavant's course has changed on multiple occasions, one significant instance being in Roman times when the river was believed to have been diverted through Chichester to provide drinking water for the town. The Lavant is believed to have made its way to the sea via Pagham Rife and Pagham Harbour. Newbury notes historians have conjectured this diversion may have taken place in either Roman or medieval times, one side effect being less stress on drainage to lands to the north of Pagham. The River Lavant is one of three designated chalk rivers, in Sussex.Its name probably originated from the ancient
British period but is derived from the Latin verb
lābor or
lāboris meaning 'to glide' . The term in Hampshire and the west of Sussex is a dialect word for a stream liable to flood violently without warning.
Floods The Lavant has been responsible for multiple flooding events throughout recent centuries, with the St Pancras area of Chichester being most typically affected. Floods were recorded in 1713, 1763, 1771, 1797, 1809, 1826, 1938 and 1960. In January 1994 heavy rainfall caused the River Lavant to burst its banks, causing extensive flooding in Chichester and surrounding villagesthe worst for 130 yearsand forcing the closure of the
A27 and
A259 roads. Military "
Green Goddess" fire engines were stationed in the city for several weeks pumping out groundwater through miles of pipes. When exceptionally high rainfall in the autumn of 2000 threatened renewed flooding of Chichester a project was led by the
Environment Agency, using emergency powers to build a relief channel to divert excess water back into the natural route of Pagham Rife. This brought forward work planned for 2001, compressing it into two weeks, and was completed days before the anticipated flood surge in the River Lavant occurred. The emergency work was subsequently made into a permanent relief channel, with sluices at
Westhampnett.
Environmental concerns In the early 2020s the River Lavant became the subject of significant environmental concern due to repeated sewage discharges by
Southern Water. Regional and national media reported prolonged and, at times, continuous releases of untreated wastewater into the river and its tributaries, leading to the growth of sewage fungus and severe ecological decline. Some assessments described sections of the chalk stream as “effectively dead” as a result of the pollution. ==Course==