FLOOD07246

• County: Jefferson
• Community: Buffalo Creek
• Basin: South Platte
• Title: Wildfire Flood-Hazard and Watershed-Rehabilitation Monitoring
• Date: 1/8/1998
• Prepared For: CWCB
• Prepared By: USGS
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

in burned areas. Add~ional research objectives are to: 1.) determine the length of time for the basin to
return to pre-fire conditions; 2.) assess the effectiveness of watershed-management practices used to

mitigate water and sediment runoff; 3.) compile merature on wildfire-hazard mitigation; and 4.) develop a

paleoflood-based monitoring program that provides data needed for subsequent ecological and forest

rehabilitation activ~ies. Limited resources preclude extensive, instrumented data-collection efforts, and

there also is a likelihood floods may not occur in instrumented basins. Data mon~oring needs to begin

immediately after a wildfire because important data are lost shortly after each storm and hazard-m~igation

efforts. Monitoring in burned and unburned areas consists of determining rainfall amounts, peak flows,

and channel agradation and degradation.

The study approach was applied to the community of Buffalo Creek, located about 50 km southwest of

Denver, Colorado (fig. 1). On May 18, 1996, an intense wildfire, now known as the Buffalo Creek wildfire,

burned about 50 km2 of forest. Following the fire, rainstorms produced nine, 1 OO-year or larger flash

floods (pre-fire cond~ions). Two people were killed and several million dollars in public and private

property damage occurred for the largest flood on July 12, 1997. Additionally, xx million dollars were

spent fighting the fire and on watershed-rehabil~ation efforts. Colorado is the first state in the Nation to

create a statewide fire assessment map, which outlines areas most vulnerable to catastrophic wildfires

(USFS, written commun., 1997). Buffalo Creek is located in a moderate fire-hazard area, thus, illustrating

the potential hazards in other wildland-urban interface areas.

Background

Wildfires, which change flood and sediment production, are a natural process cr~icalto maintaining hea~hy

ecosystems and have occurred numerous times in the western Un~ed States during about the last 8,000

years (Weise and Martin, 1995; Meyer et aI., 1995). In 1997, wildfires burned more than 25,000 km2 in the

western United States, which was the most area since 1952 (National Interagency Fire Center, written

commun., 1997). Substantial resources are directed towards mitigation of water and sediment runoff in

burned areas, however, little is known about the effectiveness of watershed-rehabil~ation practices. Most

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