CLASSIFICATION OF SPRINGS 525 



DEFINITION OF THE TERM "SPRING" 

 A spring is a place where water issues from the ground and 

 flows or where it hes in pools that are continually replenished from 

 below, except that wholly artificial openings, such as artesian wells, 

 are not regarded as springs. Many springs have been modified 

 by structures intended to increase their usefulness to man. A seep 

 is a variety of spring in which the water comes, not from any 

 definite opening, but through the pores of the ground over a 

 considerable area. The amount of water yielded by most seeps is 

 small. Many marshes and swamps are actually seeps on a large 

 scale. Large ponds or lakes that are supplied with water through 

 openings in their beds are called spring-fed lakes. A series of 

 seeps and springs may occur along a line, which is then called a 

 spring Une. Many local names are used for springs, such as 

 "water hole," "cienega," and, in New Mexico, "ojo." Names like 

 American Water, Bennet's Wells, Coyote Holes, and Ojo de Gato 

 applied to springs show characteristic usage in the arid Southwest. 

 The conditions and processes that give rise to springs should be 

 distinguished from those that bring about capillary discharge of 

 ground water. The water of springs and seeps rises under pressure 

 transmitted through the water as it lies as a continuous body in the 

 voids of the rock. On the other hand, capillary discharge is due 

 to molecular attraction between the soil particles and the water, 

 acting against gravity. It takes place because the water is raised 

 from the water table through minute openings in the soil by the 

 force of capillarity and evaporates at or near the land surface. 

 No water is released except by evaporation into the air, whereas 

 the water of springs and seeps forms streams and pools unless the 

 quantity is small and the evaporation excessive. The limit of 

 depth to the water table necessary for capillary discharge to be 

 effective is dependent on the size and uniformity of the soil grains. 

 The limit of capillary rise for most soil is not over ten feet. Many 

 areas that fulfil these conditions are large and well defined — for 

 example, the alkaline flats of arid basins. 



CHARACTERISTICS OF SPRINGS 

 In addition to the rate of flow, other characteristics or peculiar- 

 ities of springs have given rise to names and classes. None of 



