![](https://webarchive.library.unt.edu/eot2008/20081106130429im_/http://www.epa.gov/epafiles/images/epafiles_misc_space.gif) |
![](https://webarchive.library.unt.edu/eot2008/20081106130429im_/http://www.epa.gov/epafiles/images/epafiles_misc_space.gif) |
Playa Lakes
This playa lake may serve as a source of irrigation water to the surrounding fields.
|
Description
Playa lakes are round hollows in the ground in the Southern High Plains of the United States.
They are ephemeral, meaning that they are only present at certain times of the year.
The temporal nature of playa lakes led to confusion on the part of early European explorers,
some of whom described the region as a desert and others a land of millions of small lakes.
Most playas fill with water only after spring rainstorms when freshwater collects in the round
depressions of the otherwise flat landscape of West Texas, Oklahoma, New Mexico, Colorado, and
Kansas. There are also a few saltwater-filled playas. These are fed by water from underlying
aquifers, which brings salt with it as it percolates up through the soil. As the water
evaporates, the salt is left behind in the increasingly salty playas. There are many theories
as to the origin of playas, but the most widely accepted are that playas are either carved by
wind or formed by land subsidence (they are sinkholes). Whatever their origin, playas are
important to humans, animals and plants of the High Plains.
|
![pictures of a redwing blackbird, Blue-winged teal, and mallard](https://webarchive.library.unt.edu/eot2008/20081106130429im_/http://www.epa.gov/owow/wetlands/types/images/birds.jpg)
Playas are important habitat for migratory birds and waterfowl. The Red-winged Blackbird (Agelaius phoeniceus), Blue-winged Teal (Anas discors), and the Mallard (Anas platyrhynchos) can all be found in playa lakes at some time of the year.
|
![picture of sandhill cranes on dugout in playa lakes](https://webarchive.library.unt.edu/eot2008/20081106130429im_/http://www.epa.gov/owow/wetlands/types/images/sandhill.jpg) Sandhill Cranes (Grus canadensis) winter in playa lakes. Their wingspan is more than six feet
|
Functions & Values
Playas are important because they store water in a part of the country that receives as
little as twenty inches of rain a year and where there are no permanent rivers or streams.
Consequently, playas support an astounding array of wildlife. Two million waterfowl commonly
winter in the playa lakes of the Southern High Plains. Mayflies, dragonflies, salamanders,
Bald Eagles, endangered Whooping Cranes, jackrabbits and raccoons also can be found at playa
lakes. Amphibians would not be present in this arid region if it were not for playas.
Because playa lakes support such a wide variety of animals, they contribute significantly to
the biodiversity of the High Plains. The surrounding land is mostly dedicated to a few
agricultural species, and some species native to the High Plains survive only because of the
existence of playa lakes. Playas also help support the surrounding agriculture by providing
irrigation water and seasonally recharging the Ogallala Aquifer. This famous aquifer
underlies the Southern High Plains and is being used for irrigation and drinking water
faster than it is being replenished.
|
![picture of an aerial view of playa lake-dotted landscape](https://webarchive.library.unt.edu/eot2008/20081106130429im_/http://www.epa.gov/owow/wetlands/types/images/playascape.jpg) An estimated 25,000 playa lakes can be found on the high plains, but no one has ever tried to count them all. Almost all playa lakes are affected by agricultural activities in one way or another in this heavily farmed region
|
Status
Today, some playas are appreciated and protected because of their value to wildlife. Playas'
importance as water storage sites is also recognized - they provide between 10 and 25 percent
of the annual irrigation water in some counties. To protect this water source from pollution,
many farmers are adopting playa-friendly farming techniques like planting native vegetation
around playas to filter sediment, fertilizer, and pesticides from the runoff that provides
playas' water supplies. Sediment in runoff can fill playas, reducing their capacity to hold water and depleting
biodiversity. An emerging threat to playas is that some farmers in the Southern High Plains
are returning to dry farming techniques, which means less rainwater reaches playas. Some new
irrigation methods can lead to decreases in the amount of water reaching playas as well, by
altering runoff patterns. In some places, playas are still used as lagoons to hold animal
waste, which seriously decreases their ability to support wildlife and can threaten groundwater
purity. |
|