Title: Rock gabion, rip-rap, and culvert treatments: Successes and failures in post-fire erosion mitigation, Schultz Fire 2010
Author: Neary, Daniel G.; Koestner, Karen A.
Source: Paper presented at the 24th Annual Symposium of the Arizona Hydrological Society; Watersheds near and far: Response to changes in climate and landscape; September 18-20, 2010; Flagstaff, AZ. 5 p.
Description: Following the Schultz Fire in June of 2010, several erosion mitigation efforts were undertaken to reduce the impacts of post-fire flooding expected during the 2010 monsoon. One treatment consisted of the placement of large rock rip-rap on targeted fill slopes of a high elevation forest road that contains a buried pipeline supplying water to the city of Flagstaff. Another treatment was culvert removal at 30 channel crossings on a forest road that transects the burn area at a lower elevation (Schultz Pass). On urbanized private lands below the fire, no road culverts were initially removed or upgraded. After initial post-fire flooding, a major, unarmored drainage ditch rated at a capacity of 14.2 m3 sec-1 was fitted with sixteen rock-filled wire cage gabions to reduce channel incision. Rainfall began in mid-July after the wildfire and produced multiple floods that caused substantial erosion, debris flows, and channel incision. The large rip-rap on the upper elevation road failed completely. Culvert removal at channel crossings within the forest functioned satisfactorily and prevented the addition of road fill and fill-breach surges to the stormflow. Road culverts in the urban area were grossly under capacity and were either buried or bypassed. The gabions in the drainage ditch functioned for a short time but were then bypassed, causing significant channel widening and transport of additional sediment. This paper takes a forensic look at these erosion control measures and discusses the reasons for failure or success. Recommendations are made for future use of these erosion control techniques.
Keywords: erosion, post-fire flooding, Schultz Fire
View and Print this Publication (597.95 KB)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility
Neary, Daniel G.; Koestner, Karen A. 2011. Rock gabion, rip-rap, and culvert treatments: Successes and failures in post-fire erosion mitigation, Schultz Fire 2010. Paper presented at the 24th Annual Symposium of the Arizona Hydrological Society; Watersheds near and far: Response to changes in climate and landscape; September 18-20, 2010; Flagstaff, AZ. 5 p..