The playas serve as recharge water for the Ogallala Aquifer and habitat for migratory birds. Wetland Functions Wetlands are among nature's most biologically productive areas. In commercial terms, fishing, hunting, timber production along with fur and hide harvesting contribute billions of dollars per year to the nation's economy. Texas is a primary wintering area for North American waterfowl. More than 15 million birds migrate annually through the playa lakes.
Wetlands also perform important physical and chemical functions.
By controlling floodwater, they help minimize the costs of disaster relief and property repair. Freshwater wetlands next to streams control shoreline erosion and intercept eroded soil from upland areas. Erosion creates navigational problems that can cost millions of dollars to repair. Certain freshwater plants have proven beneficial for secondary treatment of sewage effluents. Marshes can filter nitrates and phosphates from rivers or creeks that receive treated sewage from upstream sources.