Perennial Marshes/Cienegas/Springs/Seeps [PMCSS]: Perennial marshes or cienegas are water-saturated, poorly drained wetlands permanently inundated up to a depth of 2 m (7 ft). They support an extensive cover of emergent non-woody vegetation without peat-like accumulations (marshes). They are associated with perennial spring and seep systems in isolated arid basins of the Southwest (cienegas). A perennial spring occurs where an underground source of water emerges from the ground, generally from a single point of origin, forming a stream, pond, marsh, or other type of water body. A seep is a generally small area where water percolates slowly to the ground surface, typically without a well-defined point of origin. Seeps generally have a lower flow rate than springs and rarely have enough water volume to form a substantial water body.