Center's logo National Web-Based Learning Center for Nonfederal Forest and Range Lands
Center's logo
home || search this site || learning options || references & links
 

 

 

Home
Introduction
Streams & Watersheds
Functions and Conditions
Grazing the Landscape
Grazing Riparian Areas
Grazing Management
Management Plan
Supplemental Material
 

 

Page 5 of 16
Topics within this tutorial

 

 

Streams and Watersheds - Introduction

Method 3 = In relation to landscape and water table

Figure 1-4
Whether a segment of a stream is a "gaining" or a "losing" reach depends on the relationship between the groundwater table and the streambed.

A third way to classify streams is based on their relationship to the landscape around them and the groundwater table. In this classification system, streams are either "gaining" or "losing" streams (Figure 1-4).

  • A gaining stream is one in which the channel bottom is lower than the level of the surrounding groundwater table. Through the course of the summer, water moves from the ground into the channel.

  • A losing stream is one which is above the groundwater table, and water moves from the channel into the surrounding ground.

Perennial streams are generally gaining streams, while intermittent and ephemeral streams are often losing streams. Many streams, however, are composed of reaches (portions of a stream) which are gaining reaches and others that are losing reaches.