Station Fire Research

  

So. CA Station Fire 2009: Effect on Water Systems, Drains, and Debris

The Station Fire of Southern California was a big fire in Los Angeles County that started on August 26, 2009 in the Angeles National Forest near La Canada Flintridge. The fire destroyed  approximately 161,000 acres in all, 154,000 acres of which served as Forest Service systems. (ANGELES NF - STATION FIRE Burned Area Emergency Response) This fire burned a span of just over a week but damaged much of the Angeles National Forest and nearby water systems which may have caused danger of major floods, mud slides, and debris flows. My thematic map shows the extent of the fire on August 26, 2009, and September 1, 2009. The map also displays poly-lines and polygons of the bodies of water in the area and the direction the water flows, as well as the debris basin and storm drain points nearby. This will help us analyze and describe  the effects the fire had on the nearby water systems and debris. USGS also has interactive maps which shows how the fire has affected the area and the possibility of these problems occurring. “Much of the watershed was severely burned by the Station Fire of October, 2009. Because of this, downstream areas are at high risk for flooding or debris flows.” (USGS California Water Science Center)

Fire affects everything in its path, including the plants and soils, which in turn can have an effect on the water. In this case, the fire destroyed much of the plants and trees that were in its path, but it also opened up many seeds that need fire to open. This allows these trees to grow again, but the environment the fire created may not be the best for the plants. When a fire burns through an area, it can make the soil more fertile by adding many nutrients, but it can also have the opposite effect where it destroys the soil. In the case of the Station Fire, some areas of soil have become “hydrophobic” which can have a negative effect not only for the plants, but for humans as well. “Due to the lack of ground cover in Station Fire burn areas, as well as this hydrophobic layer, soils in the burn area are substantially more unstable in post-fire conditions than pre-fire. This change in the affected environment introduces increased risk to water quality, as well as risk to human life, property, and infrastructure associated with potential flood and debris flow damage.” (4.7.2, Hydrology and Water Quality,) The effect the fire had on the soil can be one cause of the many floods and debris flows we have seen since the fire burned in 2009. 

As we can see in the slope map, the area south of the final fire extent seems to be the steepest, this may cause the water in the Big Tujunga Canyon, Tujunga Wash, and the nearby streams to run in the direction of Hansen Lake in the West, and the West Fork San Gabriel River and nearby streams to run into the Cogswell Reservoir on the East. We can also see the greater amount of storm drains and debris basins in the southernmost part of the fire extent. The effect of the fire on the soil may have caused it to give way easier, affecting the nearby bodies of water to overflow or jam with either water (floods), mud, or debris during the rain season. Depending on the extent of the fire, this problem could be dealt with quickly and easily, or over a long period of time. Unfortunately, since the Station Fire caused a great amount of damage, this problem will have long term effects on the nearby areas. “The Forest Service and LA County are looking at the full scope and scale of the situation. The increased potential for floods and debris flows are not just a one-year concern; affected communities could be impacted 3-5 years until the burned area fully recovers.” (ANGELES NF - STATION FIRE Burned Area Emergency Response) One manner in which the county is trying to fix this is with debris basins all along the Southern part of the fire. 

Debris basins are an essential part of the clean up of this fire since they help collect all the debris while allowing water to flow to prevent floods. “Debris Basins are key components of the Los Angeles County Flood Control District’s flood control system. Typically located at the mouths of canyons, debris basins capture sediment, gravel, boulders, and vegetative debris that are washed out of the canyons during storms but allow water to flow into the downstream storm drain system, thereby protecting drainage systems and communities in lower-lying watershed areas from possible flooding and property damage.” (County of Los Angeles Department of Public Works) The debris collects in these areas until the county collects and disposes it. Since the fire was very bug, the amount of debris it has created is also quite large. In fact, “The District removed close to 1.3 million cubic yards of material from its debris retention facilities. According to storm season projections, the District will need to dispose of an estimated 1.2 million cubic yards of material each storm season for the next 3-5 years, as watersheds affected by the recent wildfires recover.” (Department of Public Works Sediment Management) Debris is just one of the many problems the fire has created for the residents and the county to deal with. 

In conclusion, the Southern California Station Fire in the summer of 2009 has greatly affected the surrounding systems of water by creating unstable soils which led to mud flows, debris, and floods. The county is doing as much as it can to help clean up the mess by cleaning out the debris basins which have collected much of the debris. This problem, unfortunately, will take time to fully clear up since the size of the fire was really big. The slope in the southernmost part of the fire extent is also contributing to much of the debris flowing into nearby streams and bodies of water, but there is nothing the county can do about it. As for the future, we will have to wait and see how the storms affect the amount of floods and debris in the area.

Map shape-files and Information obtained through:

Debris Basin: Hydrography “Debris Basin (Point Locations)” Los Angeles County Enterprise GIS: Public Works Data  http://egis3.lacounty.gov/eGIS/ 

Flow Direction: Hydrography “Watershed Sub Basins- Water Flow Directions” Los Angeles County Enterprise GIS: Public Works Data  http://egis3.lacounty.gov/eGIS/ 

Intermittent Streams/Creeks: Los Angeles County Rivers and Streams (Polyline, 2008) UCLA Mapshare http://gis.ats.ucla.edu

Lakes/Bodies of Water: U.S. National Atlas Water Feature Areas for Los Angeles County (Polygon, 2006) UCLA Mapshare http://gis.ats.ucla.edu

Storm Drains: Utilities “Storm Drain Annotation Points” Los Angeles County Enterprise GIS: Public Works Data  http://egis3.lacounty.gov/eGIS/

Streams/Rivers: U.S. National Atlas Water Feature Lines for Los Angeles County (Polyline, 2006) UCLA Mapshare http://gis.ats.ucla.edu/ 

Works Cited

Burned Area Emergency Response. ANGELES NF - STATION FIRE Burned Area Emergency Response · BAER   Implementation. Rep., 04 Nov. 2009. Web. 7 June 2011. <http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev3_020019.pdf>.

"Sediment Management." Dpw.lacounty.gov. Los Angeles County. Web. 07 June 2011. <http://dpw.lacounty.gov/lacfcd/sediment/dspFeedbackResponse.aspx>.

Tehachapi Renewable Transmission Project , comp. Hydrology and Water Quality . Issue brief no. 4.7. 2011. Web. 05 June 2011. <http://docs.cpuc.ca.gov/environ/tehachapi_renewables/TRTP-SDSEIS/SDEIS/4.7_Hydro-WQ.pdf>.

USA. LA County. Department of Public Works. Debris Basin Point Locations. 2011. Web. 7 June 2011. <http://gis.dpw.lacounty.gov/oia/metadata.cfm?path=debrisbasin_pt.htm&zip=Debris%20Basin%20(Point%20Locations).zip>.

"USGS California Water Science Center Information Requests." USGS California Water Science Center. Ed. USGS. 04   Oct. 2010. Web. 07 June 2011. <http://ca.water.usgs.gov/webcams/>.