Topography

Dallas and its surrounding area are mostly flat; the city itself lies at elevations ranging from 450 to 550 feet (137 to 168 m). The western edge of the Austin Chalk Formation, a limestone escarpment (also known as the "White Rock Escarpment"), rises 230 feet (70 m) and runs roughly north-south through Dallas County. South of the Trinity River, the uplift is particularly noticeable in the neighborhoods 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, as well as along Turtle Creek north of Downtown.

Dallas Arboretum

Dallas, like many other cities, was founded along a river. The city was founded at the location of a "white rock crossing" of the Trinity River, where it was easier for wagons to cross the river in the days before ferries or bridges. The Trinity River, though not usefully navigable, is the major waterway through the city. Its path through Dallas is paralleled by Interstate 35E along the Stemmons Corridor, then south alongside the western portion of Downtown and past south Dallas and Pleasant Grove, where the river is paralleled by Interstate 45 until it exits the city and heads southeast towards Houston. The river is flanked on both sides by 50 feet (15 m) tall earthen levees to protect the city from frequent floods.^[32]
Since it was rerouted in the late 1920s, the river has been little more than a drainage ditch within a floodplain for several miles above and below downtown Dallas, with a more normal course further upstream and downstream, but as Dallas began shifting towards postindustrial society, public outcry about the lack of aesthetic and recreational use of the river ultimately gave way to the Trinity River Project,^[33] which was begun in the early 2000s and was scheduled to be completed in the 2010s. If the project materializes fully, it promises improvements to the riverfront in the form of man-made lakes, new park facilities and trails, and transportation upgrades.
The project area will reach for over 20 miles (32 km) in length within the city, while the overall geographical land area addressed by the Land Use Plan is approximately 44,000 acres (180 km²) in size—about 20% of the land area in Dallas. Green space along the river will encompass approximately 10,000 acres (40 km²), making it one of the largest and diverse urban parks in the world.^[34]
White Rock Lake, a reservoir constructed at the beginning of the 20th century, is Dallas' other significant water feature. The lake and surrounding park is a popular destination for boaters, rowers, joggers, and bikers, as well as visitors seeking peaceful respite from the city at the 66-acre (267,000 m²) Dallas Arboretum and Botanical Garden, located on the lake's eastern shore. White Rock Creek feeds into White Rock Lake, and then exits on to the Trinity River southeast of downtown Dallas. Trails along White Rock Creek are part of the extensive Dallas County Trails System.
Bachman Lake, just northwest of Love Field Airport, is a smaller lake also popularly used for recreation. Northeast of the city is Lake Ray Hubbard, a vast 22,745-acre (92 km²) reservoir located in an extension of Dallas surrounded by the suburbs of Garland, Rowlett, Rockwall, and Sunnyvale.^[35] To the west of the city is Mountain Creek Lake, once home to the Naval Air Station Dallas (Hensley Field) and a number of defense aircraft manufacturers.^[36] North Lake, a small body of water in an extension of the city limits surrounded by Irving and Coppell, initially served as a water source for a nearby power plant but is now being targeted for redevelopment as a recreational lake due to its proximity to Dallas-Fort Worth International Airport, a plan that the lake's neighboring cities oppose.^[37]