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<br />(Florsheim et aI., 1991; Weise and Martin, 1995), Helena, Montana (Parrett,
<br />1987), Yellowstone National Park (Meyer et aI., 1995; Ewing, 1996), Storm
<br />King Mountain, Colorado (Cannon et aI., 1995), the Wasatch Mountains in
<br />Utah (Evenstad and Rasely, 1995), Boise, Idaho, and Badelier National
<br />Monument, New Mexico, and Mesa Verde Natinal Park, Colorado (all in 1996)
<br />emphasize the potential risk for loss of life, property damage, and costs
<br />associated with hazard mitigation and watershed rehabilitation. The
<br />effects of flood runoff, sediment delivery, geomorphic changes, watershed
<br />recovery time, and the linkages among them are poorly understood for burned
<br />watersheds. Watershed, sediment, and ecosystem models may not be
<br />applicable without modifications for assessing changes due to burned areas
<br />(Weise and Martin, 1995). The focus of this study was to develop a
<br />flexible, cost-efficient, monitoring and analysis approach that can be
<br />quickly implemented following wiidfires wherever they may occur.
<br />
<br />Research was undertaken to monitor and determine the risk of hazards and to
<br />help mitigate, to the extent possible, loss of life and property damage
<br />from water and sediment runoff related to wildfire areas. Extensive
<br />coordination with the various government agencies involved with hazard
<br />mitigation, particularly the National Weather Service (NWS), is an integral
<br />part of our research to help determine threshold-rainfall conditions, which
<br />will change with time, that could cause hazardous flooding in burned areas.
<br />Additional research objectives are to: 1.) determine the length of time
<br />for the basin to return to pre-fire conditions; 2.) assess the
<br />effectiveness of watershed-management practices used to mitigate water and
<br />sediment runoff; 3.) compile literature on wildfire-hazard mitigation; and
<br />4) develop a paleofiood-based monitoring program that provides data needed
<br />for subsequent ecological and forest rehabilitation activities. Limited
<br />resources preclude extensive, instrumented data-collection efforts, and
<br />there also is a likelihood fioods may not occur in instrumented basins.
<br />Data monitoring needs to begin immediately after a wildfire because
<br />important data are lost shortly after each storm and hazard-mitigation
<br />efforts. Monitoring in burned and unburned areas consists of determining
<br />rainfall amounts, peak fiows, and channel agradation and degradation.
<br />
<br />The study approach was applied to the community of Buffalo Creek, located
<br />about 50 km southwest of Denver, Colorado (fig. 1). On May 18,1996, an
<br />intense wildfire bumed about 50 km2 of forest, now known as the Buffalo
<br />Creek wildfire. Following the fire, rainstorms produced nine, 1 DO-year or
<br />larger fiash floods (pre-fire conditions). Two people were killed and
<br />extensive public and property damage occurred for the largest fiood on July
<br />12, 1997. Colorado is the first state in the Nation to create a statewide
<br />fire assessment map, which outlines areas most vuinerable to catastrophic
<br />wildfires (USFS, written commun., 1997). Buffalo Creek is located in a
<br />moderate fire-hazard area, thus, illustrates the potential hazards in other
<br />wildland-urban interface areas.
<br />
<br />Background
<br />
<br />Wildfires, which change fiood and sediment production, are a natural
<br />process critical to maintaining healthy ecosystems and have occurred
<br />numerous times in the western United States during about the last 8,000
<br />years (Weise and Martin, 1995; Meyer et aI., 1995). In 1997, wildfires
<br />burned more than 25,000 km2 in the western United States, which was the
<br />most area since 1952 (National Interagency Fire Center, written commun.,
<br />1997). Substantial resources are directed towards mitigation of runoff and
<br />sediment in burned areas, however, little is known about the effectiveness
<br />of watershed-rehabilitation practices. One goal of state and federal
<br />(e.g., USFS, BLM, and NPS) forest managers is to maintain a balance between
<br />the health of forest ecosystem and minimizing hazards to the public and
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