Its watershed is on the Lanarkshire border of Ayrshire at an altitude of 810 feet (250 m) above sea-level, near Loudoun Hill, Drumclog, and 7 miles (11 kilometres) SW by W of Strathaven.

[12] The parishes that border the river's south bank are Galston, Riccarton, and Dundonald; and on its north side are Loudoun, Kilmarnock, Kilmaurs, Dreghorn and Perceton, and Irvine.

A large procumbent boulder known on the OS map as the 'Carlin's Stone' lies next to the Carlin Burn near Craigends Farm below Cameron's Moss in East Ayrshire.

It seems unlikely from the workmanship that this stone and cross have anything to do with the old chapel, but one possibility is that it came from over the entrance door to Laigh Chapelton as the custom was for a Templar property to have the 'cross' symbol of the order displayed in such a fashion[2].

Over the centuries the River Irvine and its tributaries have been associated with many violent deaths and accidental drownings, some famous enough to have been recorded and remembered in the folklore of the county.

[27] In the 19th century a Mr. Roxborough, weaver of Galston, after a drinking bout lasting several days, called for his suit one night, saying that the gentleman in black wanted him.

Leaving the house with the imaginary man he was later found drowned at the large whinstone rock near the southern termination of the Shawhill Woods at Hurlford by some of Mr John Carse's sons.

A tombstone in Dreghorn parish churchyard records the tragedy of the drowning in the Annick Water at Perceton of Aurthur Watson, aged two years and eight months on the twelfth of July 1867.

Sir Thomas was surprised on the night of 9 July 1439, whilst riding past Craignaught on his way north and although outnumbered, he and his followers fought on, even taking agreed rest periods indicated by the sounding of a horn.

A little below the watermeetings[33] of the Irvine and the Kilmarnock Water took place a pivotal incident in 1297,[34] which led to the Scottish Nation regaining its independence following what was effectively its conquest by Edward I of England.

[33] A thorn tree called the "Bickering Bush" stood nearby and a public house by that name existed in Kilmarnock until it was demolished prior to the construction of the A71 Irvine flyover across the A77 Ayr Road on the site.

[33] Three slew he there, two fled with all their might, unto their horse in a confounded fright; Left all their fish, no longer durst remain, and three fat English bucks upon the plain;

Thus in a great hurry, having got their cuffs, they scampered off in haste to save their buffs.On the upper reaches of the Irvine at Loudoun Hill, Wallace[35] intercepted a convoy and routed those accompanying the English supplies.

On 10 May 1307 Aymer de Valence,[36] King Edward's commander, fought Robert the Bruce at Loudoun Hill, who was protected on either side by peat mosses, impassable by heavy cavalry.

[39] Achruglen tower, now a ruin, was the site of the burning to death of two Campbells, the Countess of Loudoun and her son and heir, by the Kennedys of Bargany in the 16th century.

[44] Following a conventicle (an illegal religious meeting of Covenanters)[32] on the lands of Harelaw, in the Parish of Loudoun, on 1 June 1679, [45] the worshippers were warned of the approach of John Graham of Claverhouse and the King's troops.

One of these farmers horses bolted, bringing the head of a female rider into violent contact with the arch of the 'Auld Brig', killing the unfortunate woman outright.

These were often treacherous and could turn from tranquil to lethal in a matter of minutes, often with no warning as the rainfall could well have fallen far upstream or at the moors that form the watershed.

The Kilmarnock Standard newspaper recorded in 2011 that a leisure boat service had been set up in the 1930s, running from a short concrete jetty, however it was not a success and did not continue for long.

Stepping stones are marked on the 1897 OS map as being located just downstream from the present Chapeltoun bridge over the Annick Water and further upstream near Townhead of Lambroughton.

Aiton[52] states that the stones used to build this bridge were conveyed in the first wheeled carts used in Ayrshire, sledges having been employed on the poor quality roads that existed prior to this time.

It is not generally appreciated how much the Ayrshire landscape has changed its character over the last few hundred years, for even in the 1760–70 Statistical Account it is stated that "there was no such thing to be seen as trees or hedges in the parish; all was naked and open."

The river and its banks, support, amongst others, Kingfishers, tawny and barn owls, herons, moorhean, coot, mallard, ravens, rooks, treecreepers, buzzards, peewits or lapwings, roe deer, mink, moles, shrews, grey squirrels, hares, hedgehogs, foxes, badgers, pipistrelle bats and otters.

Migrating Canada and Graylag Geese frequent the nearby fields on their way up from the Solway Firth / Caerlaverock area or coming down from Spitzbergen in the winter.

The brown colour of the Irvine at places like Darvel and Newmilns is not a result of pollution, but simply organic material washed out of the peat banks at the watershed.

Occasionally a water course is reduced in volume due to changes upstream, a case in point being the Garrier, which used to drain Buiston Loch near Kilmaurs.

[58] Ancient mills, it was believed, had been piously placed by their forefathers where they could be worked according to God's order, without artificially embanking the water or turning it from its natural course, which would be sinful.

The weir at Dalgarven on the River Garnock is made of boulders which are carefully placed and locked together to create a natural millpond to supply a good head of water to the wheel through the lade.

The weir is built on a natural dyke across the Garnock at this point, its existence being carefully exploited by the monks of Kilwinning Abbey who chose the site for Dalgarven Mill.

[60] In February 2009 the Lochrig or Lochridge Burn was severely polluted with diesel oil spilled from a train derailed at the railway bridge near Peacockbank farm, Stewarton.