Succinct description of where water meets land?

Assuming that "a water's edge" marginally connotes land, too: would it be correct English if "a water's edge" were joined by an adjective describing the nature of the land?

(examples: "a sandy water's edge"; "a muddy water's edge", etc.)

You suggest a word that you could combine with descriptive adjectives; the most versatile is shore. An ocean, a river, and a (large) pond can all have a shore, and it can be sandy, muddy, rocky, etc.

Other notes, in addition to the words suggested by Kate:

• If the land meets the water with a steep drop-off, but less than a cliff (e.g. a meter), it's a bank. This can be occasionally used of oceans, but more often with rivers (riverbank is a valid compound).
• Your suggestion of "water's edge" is a common phrase, though more often used with "the" than "a," and less inclined to take adjectives.
• One note, since you tagged this "british-english": British usage in the past has often used strand for a sandy shore, where American and modern British usage would use "beach."