Runoff water will flow _____ the contour lines.

Runoff water typically flows perpendicular to the contour lines. Contour lines represent elevations on a slope; they show how steep the ground is and the general drainage pattern. When it rains, water cascading down a slope will not follow the lines of equal elevation but will instead move downhill, cutting across the contours at right angles. This behavior helps to illustrate how water gathers and erodes soil, which is a crucial aspect of managing water flow in landscaping and agricultural practices. Understanding this principle is vital for landscape contractors, as it influences design decisions related to drainage and erosion control.