Station Fire and LA Water Systems

There is an extensive network of water systems within and surrounding the San Gabriel Mountains, the site of the LA Station Fire in 2009. The LA Department of Public Works manages a flood control system that includes 14 dams, 500 miles of channels, and 3000 miles of storm drains. In this particular incident, at least six different watersheds were swept by fire (Figure B), some of this land that hasn't experienced fire activity in over forty years. 

Figure A

These water sheds are not isolated ecosystems. Canyons affected by the fire drain into the Los Angeles and San Gabriel Rivers, and these major deranges connect related populations, called metapopulations.

This means that fire damage to one habitat or species can have repercussions across the region. Some of the consequences of this fire, for example, include reduced water quality, loss of hillside vegetation, and sediment delivery. The dissemination of ash and other hazardous materials can change the water chemistry of whole streams and rivers, which carry these materials downstream and into other habitats.

Figure B

Ash and sediment delivery especially was an issue. Aquatic organisms require specific amounts of sediment to survive, and when these amounts are altered via natural disaster and human activity it can be a barrier to reproduction and recolonization, putting these organisms at risk of local extinction. A common problem with fires, and this incident was no different, is ash and sediment can shred fish's gills and drive of the alkalinity of the ecosystem. If high amounts of precipitation follows, as was the case in 2009,  aggregation of sediment and debris can form into flowing masses with the consistency of wet concrete, destroying everything in their path and pouring into the regions creeks and major drainage systems.  Wild life specialists forecasted that the sediment increase would be high for the region covered by the fire for the first year following.

A look at Figure C shows that the watershed most ravaged by the Station Fire was the Big Tujunga Creek. The Upper Big Tunjunga is a critical biological zone, home to several species of fish federally labeled as endagered or or sensitive to changes in the environment. In a region already sensitive to the pollution and fragmentation from LA's urban development, unnatural fires posed daunting challenges. Two of the populations most affected were the Santa Ana Sucker and the Speckled Dace. These species are now both more at risk due to modifications in water quality, stream side vegetation, and instream barriers.

Figure C

But there were also implications for the people who lived near the region. Loss of vegetation caused mudslides, as groundwater that used to serve hillside plants began to surface as springs and destabilizes rock and soil in some of the most tectonically active mountains in California. These slides destroyed building materials containing toxic materials like asbestos, gas, oil, and other chemicals, some of it eventually making it's way back into streams and rivers and distributed throughout the watershed.

References:

Archibold, Randal C. "After a Devastating Fire, an Intense Study of Its Effects." The New York Times. The New York Times, 03 Oct. 2009. Web. 15 June 2012. <http://www.nytimes.com/2009/10/03/science/earth/03fire.html?pagewanted=all>.

Rust, Brad, and Joe Gonzales. Station Fire Burn Area Emergency Response Hazmat Assessment Report. Rep. US Forest Service, n.d. Web. <http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5167077.pdf>

Sahagun, Louis. "Displaced Santa Ana Sucker Fish Are a Problem for Wildlife Authorities." Los Angeles Times. Los Angeles Times, 18 Jan. 2010. Web. 15 June 2012. <http://articles.latimes.com/2010/jan/18/local/la-me-station-fire-fish18-2010jan18>.

Welch, Leslie, Dan Teater, and Robin Eliason. Wildlife and Fish Technical Specialist Report Burned Area Emergency Rehabilitation for the Station Fire. Rep. N.p.: n.p., 2009. Print.

Zavis, Alexandra, and Corina Knoll. "After the Station Fire, a New Danger: Mudslides."Los Angeles  Times. Los Angeles Times, 17 Sept. 2009. Web. 15 June 2012. <http://articles.latimes.com/2009/sep/17/local/me-sandbags17>