Abstract: This report describes a small-scale water infiltration study of airfield mat-ting version 2 (AM2) at a test site on the US Army Engineer Research and Development Center’s Vicksburg, Mississippi, site. Before constructing AM2 runways, engineers must conduct a storm water drainage analysis; but no published study defining the runoff coefficient for AM2 exists. This study evaluated water infiltration of AM2 when subjected to 10-year and 100-year storm conditions from a proposed building site at Tyndall Air Force Base near Panama City, Florida. The allowable grade slopes for AM2 runways range from 1% to 3% in the longitudinal direction and 1% to 5% in the transverse direction. Multiple tests were conducted at various combinations of allowable grade slopes to determine grade slope orientation effects on AM2 runoff behavior. Runoff coefficients generally fell within the range of 0.05 to 0.10 for AM2. The highest runoff coefficients observed were within the range of 0.35 to 0.40 for a 5% transverse grade slope with a 1% longitudinal grade slope. Observation of the water infiltration behavior showed runoff increased with increasing transverse slope and de-creased with increasing longitudinal slope.