Dallas, and its surrounding area, is mostly flat and lies at an elevation ranging from 450 feet (137 m) to 550 feet (168 m). The western edge of the Austin chalk formation, a limestone escarpment, rises 200 feet (61 m) and runs roughly north-south through Dallas County. The uplift is particularly noticeable in the neighborhood of Oak Cliff and the adjacent cities of Cockrell Hill, Cedar Hill, Grand Prairie, and Irving. Marked variations in terrain are also found in cities immediately to the west in Tarrant County surrounding Fort Worth.

White Rock Lake is Dallas's other significant water feature. The lake and surrounding park is a popular destination among boaters, rowers, joggers, and bikers in the Lakewood/Casa Linda Estates neighborhoods of east Dallas. The 66-acre (267,000 m²) Dallas Arboretum and Botanical Garden lies on the lake's eastern shore.  Bachman Lake, just northwest of Love Field, is a smaller lake and park also used for recreation. Lake Ray Hubbard, a 22,745-acre (92 km²) lake, is a vast and popular recreational lake located in an extension of Dallas surrounded by Garland, Rowlett, Rockwall, and Sunnyvale. Mountain Creek Lake is a small lake along Dallas's border with Grand Prairie and is home to the (defunct as of September 1998) Naval Air Station Dallas (Hensley Field). North Lake, a small lake in an extension of Dallas surrounded by Irving and Coppell, served primarily as a water source for a nearby power plant, but the surrounding area is now being targeted for redevelopment due to its proximity to Dallas-Fort Worth International Airport (a plan that the neighboring cities oppose).

The Trinity River is a major Texas waterway that passes from the city of Irving into west Dallas, where it is paralleled by Interstate 35E along the Stemmons Corridor, then flows alongside western downtown, and through and alongside south Dallas and Pleasant Grove, paralleled by Interstate 45, where it exits into unincorporated Dallas County and heads southeast to Houston. The river is flanked on both sides by 50 feet (15 m) tall earthen levees to protect the city from floods. The river has been treated much like a drainage ditch throughout Dallas's history, but as Dallas began shifting towards a postindustrial society, public outcry about a lack of aesthetic and recreational use for the river ultimately gave way to the Trinity River Project. The project, which began in the early 2000s and is scheduled to reach completion in the 2010s, will result in lakes, new park facilities and trails, and transportation improvements.