{"id":1266,"date":"2026-05-12T21:47:16","date_gmt":"2026-05-12T21:47:16","guid":{"rendered":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/chapter\/basics-of-surface-water\/"},"modified":"2026-05-13T03:20:40","modified_gmt":"2026-05-13T03:20:40","slug":"basics-of-surface-water","status":"publish","type":"chapter","link":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/chapter\/basics-of-surface-water\/","title":{"raw":"13.2 Basics of Surface Water","rendered":"13.2 Basics of Surface Water"},"content":{"raw":"
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\r\n\r\nWhen rain falls on the Earth, some of it soaks into the ground, some is taken up by plants and animals, and some evaporates into the air. The rest of the water\u2014the part that drains to the nearest creek or river and flows towards the ocean\u2014makes up the part of the hydrologic cycle that we call surface water<\/em>.\r\n\r\n<\/div>\r\n
\r\n\r\nA stream<\/em> is the general term used to describe a body of flowing water on the Earth's surface that is contained within a channel. Streams receive their water from a surrounding area called a drainage basin,<\/em> watershed,<\/em> or catchment<\/em>. Watersheds are defined by the topography surrounding the stream, and watersheds are determined by arbitrarily selecting a point on a stream and delineating the area that drains to that point (Figure\u00a099<\/span><\/a> and Figure\u00a0100<\/span><\/a>).\r\n\r\n<\/div>\r\n
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\r\n\r\nFigure\u00a099\u00a0\u2011\u00a0<\/strong>Schematic diagram of two watersheds delineated by dashed lines with the watershed on the right that includes the headwaters being a portion of the entire water shed.<\/span>\r\n\r\n<\/div><\/blockquote>\r\n<\/div>\r\n
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\r\n\r\nFigure\u00a0100\u00a0\u2011\u00a0<\/strong>Shaded-relief image of a watershed (reproduced from https:\/\/bcn.boulder.co.us\/basin\/waterworks\/watersheds.html<\/u><\/span><\/a>\u2197).<\/span>\r\n\r\n<\/div><\/blockquote>\r\n<\/div>\r\n
\r\n\r\nSome definitions relevant to the discussion of surface water include the following.\r\n\r\n<\/div>\r\n