HYDROLOGIC RECOVERY OF TWO WATERSHEDS AFTER A WILDFIRE, BANDELIER NATIONAL MONUMENT

In June of 1977, the La Mesa fire burned 15,270 acres in and around Frijoles Canyon, Bandelier National Monument and the adjacent Santa Fe National Forest, New Mexico. The Dome fire occurred in April of 1996 in Bandelier National Monument, burned 16,516 acres in Capulin Canyon and the surrounding Dome Wilderness area. Both canyons are characterized by extensive archeological artifacts, which could be threatened by increased runoff and accelerated rates of erosion after a wildfire. The U.S. Geological Survey (USGS) in cooperation with the National Park Service monitored the fires' effects on streamflow in both canyons.

The magnitude of large stormflows increased dramatically after the fire, with peak flows at the most downstream gage in each of these two watersheds increasing to about 160 times the maximum-recorded flood, prior to the fire. Maximum peak flow was 3,030 ft³/sec at the Frijoles Canyon gage, and 3,630 ft³/sec at the most downstream crest stage gage in Capulin Canyon. The pre-fire maximum peak flow recorded at these two sites was 19 and 25 ft³/sec respectively As vegetation reestablished itself in the second year, the annual maximum peak flow was reduced to about 10 - 15 times the pre-fire, annual maximum peak flow. The third year, maximum annual peak flows were reduced to about 3 - 5 times the pre-fire maximum peak flow.

The frequency of larger stormflows also increased in response to the affects of the fires in both canyons. In Frijoles Canyon, the number of peak stormflows greater than the pre-fire maximum flow of 20 ft³/sec increased for the three water years from the date of the fire. Likewise, larger stormflows occurred more frequently in Capulin Canyon for the first three years after the fire in 1996.