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Flood-transported sediments and debris in Spring Creek dammed the South Platte River to a depth of about 3 m, which caused backwater (ponding) and reduced the peak flow from Spring Creek. The peak flow was 240 m3/s (+/- 20%) in the South Platte River downstream from the Spring Creek (fig. 1, site 5), a decrease of about 270 m3/s. Without this ponding and attenuation of the Spring Creek flood, the peak flow at the South Platte River gage could have been as large as 595 m3/s. Effects of the Buffalo Creek WildFire Two approaches were used to estimate the effect of the fire on flood runoff. First, July 12,1996 flood data for severely burned and unburned basins, which had similar rainfall amounts, were plotted against contributing drainage area (fig. 3). Peak discharge from severely burned basins was 20-40 times larger than for unburned basins. Unburned basins within areas of maximum rainfall had minimal or no runoff, which likely reflects rainfall interception by the duff in unburned areas; in addition, basin slopes in unburned areas generally are 20 percent or less. Slightly burned areas, which might have similar runoff as a prescribed-burn watersheds, had substantial flood and sediment runoff, but less than moderately- and severely-burned basins. Since the fire, rainstorms have produced 9 floods (5 in 1996 and 4 in 1997) larger than a 100-year pre-fire flood (FEMA, 1986); most storms were preceded by 5 to 10 mm of rainfall. The largest flood on July 12,1996 was about 10 times larger than the 100-year, pre-fire flood. For many burned basins, the location of exposed bedrock or firm ground to estimate discharge changed for each storm (within +/- -100 m of other sites) due to shifting channels. Therefore, a fixed streamflow-gaging station may not produce reliable records, need to be moved, or have a costly control (e.g., weir, flume) installed. The second approach compared flood data for burned areas in Buffalo Creek with other Colorado Front Range foothill extreme floods resulting from more than about 130 mm of rain in about an hour in similar basins (slopes, soils, vegetation) but were unburned (fig. 3). Runoff from Buffalo Creek burned areas is substantial more than floods in unburned basins in Colorado (fig. 3). The combined peak discharge for Buffalo Creek and Spring Creek is about 960 m3/s (- 50 km2 contributing burned area), which is greater than the 1976 flood of 883 m3/s in the Big Thompson River (McCain et aI., 1979) from a contributing area of about 250 km2. A number of severely-burned basins in areas near maximum rainfall had unit discharges (peak discharge divided by drainage area) of about 60 m3/s/km2; the maximum unit discharge is about 40 m3/s/km2 for all Colorado floods (Jarrett, 1990). Clearly, the wildfire had the major role in the severity of flooding in Buffalo Creek. Because the area of maximum rainfall (-130 mm) was within the burned area, rainfall-runoff modeling is necessary to estimate potential flood runoff, but without the fire. Effects of Watershed Rehabilitation Watershed-rehabilitation efforts utilized to help restore the Buffalo Creek burned area include: aerial and ground seeding; bonded-fiber matrix; soil tilling, contour tree felling; log and straw check dams; and untreated natural recovery (Casey Clapsaddle, USFS, written commun., 1996). These efforts to break up hydrophobic soils and slow water and sediment runoff began very soon after the fire. Most efforts were in basins posing greatest risk to the public such as Sand Draw, Spring Gulch, and Shinglemill Creek. A moderate rainstorm on June 12, 1996 (Casey Clapsaddle, USFS, written commun., 1996) and the severe flash flood on July 12,1996 washed out most of the initial rehabilitation efforts. Small Page 6