riparian [ri-pair-ee-uhn, rahy-]
adjective:
of, relating to, or situated or dwelling on the bank of a river or other body of water

(click to enlarge) Examples:
These rich ecosystems - including spring-fed streams, wetlands, riparian forests and oak woodlands - are vulnerable to declines in groundwater levels. (Ian James, How a water scientist hopes to save California habitats that could be pumped dry, Los Angeles Times, May 2024)
The bird can be seen in riparian areas, which are the transition zones between land and waterways such as rivers and streams. (Maura Fox, 'Super Bowl of birding:' 7 birds to watch for as millions fly through San Diego this spring, San Diego Union-Tribune, February 2024)
At the McGee Creek trailhead, rocky canyon slopes lead into gentler areas of streams and riparian forests. (Matt Ritter, Find the Real Super Blooms This Summer with the Ultimate Floral Road Trip, Sunset, March 2020)
Media coverage has described the Hangman Creek initiative as the largest riparian restoration effort in Spokane County's history and the first program of its kind in Eastern Washington, underscoring its clear departure from conventional restoration approaches. (Matt Ritter, World Habitat Day: Nigerian policy expert's model transforms US watershed restoration , The Guardian Nigeria, March 2020)
His reed pipe when applied to his lips gave out no melody, but a dismal wail; the sylvan and riparian intelligences no longer thronged the thicket-side to listen, but fled from the sound, as he knew by the stirred leaves and bent flowers. (Ambrose Bierce, Can Such Things Be?)
Twenty-nine species are woodland birds, and few of these seem to find satisfactory conditions in the riparian woods extending out through western Kansas. (Richard F Johnston, The Breeding Birds of Kansas)
Origin:
'of or pertaining to river banks, situated on or near a river bank,' 1849, with -an + Latin riparius 'of a river bank,' from riparia 'shore,' later used in reference to the stream flowing between the banks, from ripa '(steep) bank of a river, shore.' This is probably etymologically 'break' (and indicating the drop off from ground level to the stream bed), or else 'that which is cut out by the river,' from PIE root rei- 'to scratch, tear, cut' (source also of Greek ereipia 'ruins,' eripne 'slope, precipice;' Old Norse rifa 'break, to tear apart;' Danish rift 'breach,' Middle High German rif 'riverbank, seashore' (Online Etymology Dictionary)
Riparian came to English from the same source that gave us 'river' - the Latin riparius, a noun deriving from ripa, meaning 'bank' or 'shore.' First appearing in English in the 19th century, 'riparian' refers to things that exist alongside a river (such as riparian wetlands, habitats, trees, etc.). Some river communities have laws called 'riparian rights,' referring to the rights of those owning land along a river to have access to the waterway. Note the distinction of this word from 'littoral,' which usually refers to things that occur along the shore of a sea or ocean. (Merriam-Webster)