Figure 6. Figure shows an HEC-EFM Analysis of Simulated Cottonwood Establishment Produced by an Experimental Flow Release (bottom left) From Alamo Dam on the Bill Williams River, Arizona. Three recession rates (1 inch, 2 inches, and 3 inches per day) were tested as suitable for cottonwood recruitment. Each rate was used as a statistical parameter in HEC-EFM, which computed the point on the recession limb where the rate was last exceeded. These statistical results were output to the main interface of HEC-EFM (top) and then modeled using HEC-RAS and GeoRAS to generate spatial layers (bottom right) showing where cottonwood seedlings were predicted to establish.