The upper reaches are culverted, some underground, through mostly urban landscapes, but once it emerges into the open it flows through a nature reserve and city parks before joining the tidal River Avon at Sea Mills.

Abona was a Roman port at the mouth of the Trym which provided an embarkation point for journeys across the River Severn to south Wales.

[1] The Trym then disappears into culverts, re-emerging at Henbury Golf Club before entering the Blaise Castle estate, where it is joined on the right bank by the Hazel Brook above Coombe Dingle.

Areas of beech, oak and ash woodland support a range of other bushes and shrubs, including hazel, maple, hawthorn and blackthorn.

[1] A pollution incident by Wessex Water which allowed sewage to flow into the Trym in 2001, killing eels, sticklebacks and invertebrates, resulted in a fine following prosecution by the Environment Agency.

[8] An attempt was made in 1712 by the entrepreneur Joshua Franklyn to open a commercial dock at the mouth of the Trym, on the Roman site, but the venture foundered after a few decades.

[12][13] The flow of the river has decreased in power in recent years, partly because of surface run-off in the upper catchment of the Hazel Brook, especially from the large retail centre at Cribbs Causeway.