Playas are impacted by a variety of modifications and land-use changes that reduce their ability to function properly and continue providing benefits to the people and wildlife in this region. Common modifications include farmed playas, pitted playas, and playas with ditches or drains. In general, these modifications interrupt the natural playa hydrology, reduce their ability to provide food and habitat for birds and other animals, and may prevent recharge to the aquifer.
It is important to recognize that these modifications are land-use decisions made by farmers and ranchers to support their livelihoods. Understanding both sides of this issue is critical because playa conservation does not happen in spite of landowners; it happens because of landowners. Over 80% of playas are located on private lands, thus playa conservation requires common sense solutions that help both people and wildlife.
In their natural condition, playas are covered by grassland; however, today many playas are farmed. Playas may be completely farmed (like the one in the satellite image to the right), partially, or just surrounded by farmland. View more examples of farmed playas.
Playas can be a blessing and a curse in farm fields. In dry years, the clay soils may retain more moisture, generating higher crop yields than in surrounding areas. But in wet years, playas fill and can drown the crops planted there. Farmers with playas in their fields must make important decisions every spring, to plant the playa and risk crop damage, or to avoid the playa making planting and harvesting harder and potentially losing revenue on two fronts.
From a wildlife perspective, playas in farmland can provide less food and roosting habitat than grassland counterparts. Although many species of birds eat waste grain, they may spend more energy flying to deeper, wetter playas to roost.
Hydrologically, farming playas breaks up the important clay layer. Additional sediments are introduced when machines are driven through the playa and by erosion from heavy rains. The additional sediments can fill the playa, preventing water from pooling and reducing the capacity of the playa to recharge the Aquifer.
Playas with Pits
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 systems, 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 cases, 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. View examples of playas with pits.
Playas with Ditches or Drains
Ditches and drains are often found in playas throughout the western Great Plains as a means of draining water into another nearby drainage or into a pit within the playa. Like the other changes described here, the main effects of drains are to interfere with the natural hydrology of playas (e.g., reduce their ability to recharge the Aquifer) and to allow additional sediments to accumulate in playas. Fortunately for landowners interested in restoring drained playas, there are cost-sharing opportunities available.
Ditches and drains can often be seen connecting to pits within playa basins. If there is a linear feature within a playa that isn’t a road, chances are it’s a ditch. In some regions, ditches lead from a playa basin out into another drainage (though this occurs less often than draining into a pit). View examples of playas with ditches.