Playa Lakes Joint Venture (PLJV) has developed Energy Development Siting Recommendations for Playas, which take a precautionary approach around playas by advising that all energy development and associated infrastructure avoid playa clusters. We believe infrastructure on or near playas, playa clusters, or large isolated playas may adversely affect wildlife habitat and may increase the risk of collision mortality for waterfowl and other wetland birds. This guidance depends on PLJV’s mapping of playa clusters, which can be viewed and downloaded as part of our playa decision support system.
Playas are round, shallow, clay-lined wetlands found throughout the short- and mixed-grass prairie region. Precipitation and associated runoff is the sole source of water for playas. Once a playa has filled it may remain wet for several months, eventually drying out to start the process all over again. The hydroperiod of individual playas is highly variable over time and differs amongst playas.
As of this writing over 80,000 playas have been mapped in the western Great Plains region. The distribution of playas varies across the region; playas are sparsely distributed in some areas and clustered in other areas. These high density clusters of playas have been shown to host significantly greater numbers of waterfowl than other areas. In areas with few playas, large isolated playas can serve as stepping stone wetlands which connect playa clusters for feeding waterfowl.
Waterfowl (e.g., ducks and geese), shorebirds (e.g., plovers, rails, sandpipers) and waterbirds (e.g., cranes), as well as the birds that prey on them (e.g., raptors), use inundated playas during migration as stopover points for feeding and resting. Proximity of infrastructure to playas may directly affect avian mortality as birds traverse among playas, and the constant disturbance and persistent noise in the area may indirectly impact many bird species. Where playas are the only source of nearby surface water, they can attract many species of wildlife, often in high concentrations. Wet playas are known to be habitat for amphibians, a taxon which is experiencing world-wide declines, and reptiles such as the yellow mud turtle. Bats are known to feed on emerging insects at wet playas. Placement of energy infrastructure in playas may reduce water-holding capacity and reduce or degrade habitat for wetland dependent species.
Energy development on playa wetlands (either directly within a playa or among a cluster of playas) may limit the hydrologic function of the playas. Playas recharge the High Plains (Ogallala) Aquifer by allowing percolation of surface water through the clay layer of soil in the basin. Recharge through playa basins occurs at a rate one to two orders of magnitude greater than through inter-playa areas.