Lubbock County, TX Environmental Rules: Erosion Control (2026)

6, Drainage Structures, requires that the design of drainage channels account for water velocity and be shaped, graded, lined or otherwise protected to minimize or prevent scour erosion from excessive velocities, and it expressly extends that requirement to the roadside drainage ditches commonly called bar ditches, not just engineered channels inside a subdivision. 6 calls for concrete or rock retards built to Texas Department of Transportation specifications or Lubbock County's own specifications. The same section requires open channels to follow one of three design methods, earthen, lined, or natural channels approved by the County Transportation Administration, and sets minimum storm runoff frequencies the erosion-control design must hold up against: twenty-five years for bridges, ten years for culverts under sixty inches, and two years for curb-and-gutter and storm sewer sections; residential streets must be designed to protect abutting private property through a twenty-five-year peak storm flood.

6 further specifies flat-bottom ditches with an eight-foot bottom width, a depth capped at nine inches, and cross slopes no steeper than 18 to 1, measures aimed at keeping flow velocities low enough to avoid scouring the channel. All drainage pipe used to meet these standards must be new material, and the Transportation Administration signs off on the final design before a plat is approved.