Maybe. Free-falling in a swamp and on his instructor saved one client (David Meek) in a tandem jump, but the instructor (Jim Horak) died... although not right away. It took hours for them to be found by emergency services in the swampland. The fall was from 15,000 ft; the primary parachute tangled, and the secondary failed to deploy.
Also, Yulia Yevdokimenko, survived falling into "a swampy river with the depth of 0.5 m (1.6 ft)" from 800 m (2,620 ft) after her parachute failed to open.
One of the earliest cases of survival recorded in some detail (mentioned in a review paper):
In 1885, an English woman was reported to have survived
a fall from a 250-foot-high suspension bridge. Her survival was attributed to
"her voluminous dress and petticoat acting as a parachute" and the fact that
she landed on a mud bank.
the original source cited in the paper for this case is the 1977 edition of the Guiness Book of World Records. It turns out the paper is talking about Sarah Ann Henley.