This is the 5904th most frequent Russian word.
речного
"Речного" means "river" or "of the river" in English, relating to a river.
In this sentence, "речного" modifies "берега" to describe the type of the shore—specifically, a shore by a river, indicating possession or association with a river.
Мы гуляли вдоль речного берега и наслаждались видом.
We walked along the riverbank and enjoyed the view.
Here, "речного" is part of "речного происхождения" describing the origin of the water, specifying that it comes from a river.
Вода речного происхождения часто используется для сельского хозяйства.
Water from river origin is often used for agriculture.
In this case, "речного" describes "течения" to characterize the flow as that of a river, associating the sound specifically with the movement of river water.