The outlet forms the Waccamaw River which flows south-southwest to empty into the Atlantic Ocean near Georgetown, South Carolina Lake Waccamaw has a broad, flat bottom of gyttja (mud) and peat, encircled by sandy shallows and submerged sandy terraces that extend up to 1,650 ft (500 m) offshore.

The marginal 70% of the lake bottom is composed of clear sand, whereas the central 30% is overlaid with a deposit of fibrous and pulpy peat.

A limestone bluff along the north shore filters the water and reduces the acidity levels, making the lake ideal for a wide range of aquatic life.

Recent work by the U.S. Geological Survey has interpreted the Carolina Bays formed several thousands of years ago when the climate was colder, drier, and windier.

[6] Thermokarst lakes develop by thawing of frozen ground (permafrost) and by subsequent modification by wind and water.

The skull of the whale has been restored and is currently on display at Lake Waccamaw State Park through longstanding loan from the North Carolina Museum of Natural Sciences.

The lack of rain in the eastern portion of North Carolina during 2007 affected the water level in Lake Waccamaw.

[12] Before the arrival of European settlers to the area surrounding Lake Waccamaw, it was inhabited by Native Americans.

They were replaced by people such as John Powell, who brought cattle from Virginia to settle his grant of land.

The publication from that trip was called “A New Voyage to Georgia.” From old Brunswick they traveled 40 miles (64 km) up the Cape Fear River to Moore's place, then to Lake Waccamaw, described by an unnamed author as “the pleasantest place that ever I saw in my life.” John Powell's son, Absalom, after the American Revolutionary War, started buying large areas of land.

John Powell's son, Isaac, of Lake Waccamaw was appointed first major for Bladen County militia in 1804 and a Justice of the Peace in 1806.

He was the largest landowner of his day in Columbus County, owning over 10,000 acres (40 km²) - most of his land in the area of Lake Waccamaw.

A natural sand bar, which extends along the northwest shore between a fringing cypress swamp and the main lake, was supplemented with spoil dredged to form a neighboring canal in 1946 and developed with private residences.

Big Creek delivers tea-colored water from the large cypress and gum tree swamp at the northeast corner of the lake, and the Waccamaw River emerges from the southern shore.

A dam at the outlet, built in 1926, now regulates lake levels,[13] which used to fall by as much as a meter during dry spells, occasionally exposing the sand terraces.

One legend told is the story where the meteor (falling star) hit the earth on the southeast side of the lake and destroyed all the beautiful flowers that were placed in the garden by the warriors when they came back from a hunt or from protecting the village.