Misconceptions About Pits Photo by US Forest Service

Misconceptions About Pits

MISCONCEPTION: Filling pits in playas would be very costly for the landowner.
Filling a pit is typically one of the more inexpensive playa restoration projects a landowner can pursue. Spoil piles from the original pit excavation are often still near the playa and should be reused as fill. There are conservation programs that can help defray the cost. For more information about program or tips on filling a playa, contact us.

MISCONCEPTION: There is no positive impact of filling a pit, because the pit helps the playa hold water.
A pit may trap and hold water for a longer period of time but at the cost of keeping the rest of the playa functional. If the entire playa basin does not receive water, it cannot go through a critical wet and dry cycle, which is necessary to provide habitat for wildlife and to recharge the aquifer. Once the pits are filled, rainwater and runoff can reach the large cracks in a dry playa — which is essential for recharge to occur — rather than collecting in the pit. The shallow water that spreads across the playa also allows plants to flourish, which in turn provides important food and habitat for migrating birds and other wildlife.

MISCONCEPTION: It is better for wildlife to leave the pit as it is.
The best playa for wildlife is a healthy, restored playa with its natural hydrology intact. Healthy, functioning playas attract thousands of birds — from waterfowl, cranes, and shorebirds to landbirds and pheasants. Capturing rainfall in a pit leaves little surface area for use by birds and prevents unique, nutritious plant and animal life from growing in the playa basin. Some ducks and geese may use the pit for resting but other species that like to wade in shallow water can’t use pits. Also, studies have shown that there is less food available for birds in pits compared to playas that flood naturally.

MISCONCEPTION: The pits were originally created to collect water for flood irrigation, and although they now serve a different purpose, it is not at all negative.
True, some landowners have found alternative uses for pits. And, if the pit is essential to your operation, then it should be used. However, some uses, like watering livestock, can also be accomplished by developing an upslope watering source with the added benefit of providing a constant flow and better quality of water, independent of rainfall. Water found in a pit can often be unhealthy compared to water from a well. By using strategies that don’t involve pits, you can have a naturally functioning playa that recharges the aquifer and provides food and habitat for wildlife. For more information about conservation options for your playa, contact us or your local USDA Service Center.

MISCONCEPTION: Pits need to be made deeper.
There is no evidence that pits recharge the aquifer, or at a faster rate, than a naturally functioning playa. A naturally functioning playa, with no pits, will send more and cleaner water toward the aquifer. When a pit is dug, the clay soil may be broken and/or removed. Without that clay lining, the cleaning function of the playa is circumvented. Experiments conducted by the Texas Water Development Board to test these deep pits demonstrated that recharge function ceased, on average, after two years. Although some pits hold water for far longer than a natural playa, that is only evidence the water is being held; it is not being cleaned, nor infiltrating and flowing toward the aquifer.