Water walk spells generally in DnD have been low to mid range. caster only maybe level 2. And besides from perm ww items you enchant in some games I have never heard of a perm WW spell.
Look at it this way WW spell caster only. last 3 turns...Cast it and walk blindly into the sea in hope of hitting land, you drown!....or not. You end up in the middle of monster central and cant cast it again to get away due to regen, you die another horrible death. OR.... For the next 150 turns you cast raise land go rest, raise land go rest.
I know whats more exciting for me, to each his own.