Pits, or reuse pits, are deep holes excavated in the basin of a playa. In the past, pits were often dug to help irrigate surrounding land. Gravity irrigation systems were an important practice for irrigating crops. Water was pumped to the uphill side of a field, allowed to run downhill, then collected in reuse pits and cycled back to the top of the field. Pits were also created to collect water for livestock. Pits concentrate water into a small area which does not allow the entire playa basin to fill to capacity. The result is that a pitted playa does not undergo the natural cycle of wet and dry that a non-pitted playa would. In turn, this limits a playa’s potential for wildlife habitat and aquifer recharge.
More efficient irrigation technology like center pivots and underground drip, have eliminated the need for gravity irrigation in many parts of the High Plains; thus, many reuse pits no longer serve their original purpose and could be restored. For pits used to water livestock, there are also programs available through the Natural Resources Conservation Service or Farm Service Agency to help producers create off-site water sources which would allow the playa basin to be restored.
Varying in size and shape, pits are most often circular or rectangular. They’re often noticeable on satellite imagery with two or four piles of excavated dirt around them. In many case pits may be incorporated with ditches or drains to move water from other parts of the playa. Pits are often located in the center of a playa, but this is not always the case. Look at the typical examples below to get an idea of what pits look like from satellite imagery.
To understand the different ways pits can look, view more examples of playas with pits.