Water Distribution Grade 1 Certification Practice Exam

What is the name of the area that collects surface runoff for a single drainage system?

1. Watershed

2. Catchment area

3. Drainage basin

4. Water source

The correct answer is: Watershed

The term that accurately describes the area that collects surface runoff for a single drainage system is "catchment area." A catchment area, also known as a drainage area, is defined as the region from which all precipitation collects and contributes to a specific outlet, such as a river, lake, or drainage system. When precipitation falls in this area, it flows over the land surface (surface runoff) and combines in channels or other waterways that ultimately lead to the designated drainage point. This concept is crucial in understanding how water flow is managed within a watershed or drainage basin, as it helps quantify water availability and is essential for effective water resource management. While "watershed" and "drainage basin" are terms often used interchangeably and generally refer to similar concepts of water collection areas, they can encompass larger regions with multiple catchment areas contributing to a single larger body of water. "Water source" specifically refers to sources from which water is obtained, but does not describe the area of runoff collection. Therefore, "catchment area" best fits the definition related to surface runoff for a single drainage system.