USC Dana and David Dornsife College of Letters, Arts & Sciences > Blog

March 19, 2012

LA River: “The Concrete Coffin”

Filed under: Environmental Risk — Tags: , , , — dginsbur @ 11:20 am

Los Angeles, like many cities, grew along the banks of its water source (History of the Los Angeles River). After some time, the Los Angeles River proved to be a liability to Angelinos because of its extreme flooding. After a particularly vicious flood 1914, and another one in 1934. The Federal Congress passed the Flood Control Act, which allowed the U.S. Army Corps of Engineers curb the 52 mile river by building dams and channelizing all but 10 percent of it.

The concrete paving and straightening of the river increased the speed of the river’s flow by reducing friction between water and its channel, and by reducing the distance the water would have to travel before exiting the watershed by means of ocean. The new cement walls and bottom that lined the River ensured that the city was protected from floods but it also completely changed the river into a “concrete coffin.” (History of the Los Angeles River)

The L.A. River’s unique flora and fauna benefited the least from the development, as their habitat was completely wiped out. Before the dramatic growth and urbanization of Los Angeles, the River and its banks provided unique habitat for many plant and animal species. Flora included sycamore, alder, cottonwood and oak trees, as well as elderberry, cattail, and mugwort plants. Fauna included the now endangered yellow-billed cuckoo, steelhead trout, Pacific lamprey eel, Pacific brook lamprey eel, Santa Ana sucker, and many more species. Revitalization efforts of the river have resulted in stocking the river with non-native species for fishing, and non-native species are known to have negative effects on native ecosystems. There have also been major encroachments of non-native plant species like fennel, mustard, palm, and cocklebur. (Education…FoLAR).

The concrete paving of waterways in essence, replaces vegetative cover with impervious concrete. It lowers the capacity for absorption and infiltration of the precipitated water because de-vegetation reduces the organic matter content of the ground and replaces it with surfaces that are water cannot permeate well through, like cement (Wilson “Floods”). Vegetation is essentially a buffer between precipitation and flooding, and its deficit increases flood frequency and magnitude.

A solution for improvements to the L.A. River fit under the category of revitalization efforts. Various conservation groups advocate distinct methods to achieve revitalization, though the general trend is to reduce the presence of the “concrete coffin” and increase the amount of recreational space alongside the banks of the river. It would be best to advocate the restoration of riparian habitats and the cultivating of native species that were traditionally present. These native species would most likely work the best due to their natural temperature and climate, as well as have the least amount of negative effects on other native species. Many also recommend the building of compact mixed-use developments and parks alongside the banks of the river in order to create a kind of civic space. (“Guide to the Los Angeles River- Revitalization.”)

Sources:

“HISTORY OF THE LOS ANGELES RIVER.” Dpw.lacounty.gov. Los Angeles Department of Public Works. Web. 15 Nov. 2011. <http://ladpw.org/wmd/watershed/LA/History.cfm>.

“Birds, Plants, Fish.” Friends of the Los Angeles River (FoLAR). (FoLAR). Web. 1 Nov. 2011. <http://folar.org/?page_id=8>.

“Guide to the Los Angeles River- Revitalization.” Http://thelariver.com. Los Angeles River Revitalization Corporation. Web. 1 Nov. 2011. <http://thelariver.com/about/>.

Sarah Beshir and Ashley Lukashevsky are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.

Revitalizing the Concrete River: the Benefits of LA River Restoration

Filed under: Nutrient Pollution,Stormwater Runoff — Tags: , , , — dginsbur @ 10:56 am

Flowing some 51 miles through Los Angeles city sprawl, the course of the Los Angeles River cut an ever changing path from the San Fernando Valley to its mouth in Long Beach. In early years, the natural flow of the river played an important role in the settling of the Los Angeles area. The river provided water and nutrient rich soils to a growing farming community, and people began to develop the floodplain area. However, devastating and deadly flooding in 1914 and the 1930s prompted the channelization of the river; the United States Army Corps of Engineers soon encased the river in concrete; altering the natural flow, and functions of the river (FOLAR 1). Since then, the concrete river has often been referred to as a “stain” and an “eye-sore” to the city of Los Angeles.

Recently, after years of neglect, focus has turned to revitalizing the river and its surrounding environment. Various nonprofit organizations, and environmental groups, emerged to advocate for the river’s restoration, and in 2007, the city approved the “Los Angeles River Revitalization Master Plan”. The plan specifically targets a 32-mile stretch of the river, and outlines the removal of concrete where feasible, along with the creation of open-space, parks, residential, and business areas along revitalized riverbanks (Hymon 1).

Although restoring the river to its true natural state is impossible due to developments in areas of the rivers natural flow, the loss of natural vegetation, and the loss of native wildlife, the revitalization plan brings new hope to the area. The plan will significantly increase the aesthetic appeal of the area, and the economic benefit from a restored river is expected to be great. The city believes a renewed river has vast potential for recreation, open space, and greener communities. Lush riverbanks are envisioned to attract residents and business centers to the area. Numerous bike paths, pedestrian bridges, and waterways will connect a network of public parks along the river; promoting all sorts of recreational activities.

In addition to improved aesthetics, and the associated opportunities, revitalization brings environmental benefits as well. Removing concrete will improve nutrient recycling, create habitats for wildlife and vegetation, and recharge aquifers. Returning the river to a more natural state will hopefully create a healthy and thriving ecosystem; all the while retaining flood control. The plan outlines flood prevention as a priority and considers the use of detention areas, channel expansion, and watershed prevention practices as possible ways to ensure retention of the flood control benefit from channelization.

Many people are expected to benefit from this revitalization. Over one million people live near the river, along with over 35,000 businesses, and 80 plus schools that are in close proximity to the river (City of Los Angeles 1). Revitalizing the river means revitalization for many neighboring areas and communities. The goals are to create a more aesthetically appealing environment, try to “green” the community, and improve the overall quality of life of Los Angeles residents.

The LA River plan also targets many region wide problems, such as trash and contaminated runoff, and is designed to work in conjunction with other projects meant to improve the quality of the LA river watershed.

Those in opposition of the plan argue the plan is too ambitious, costly, and that money would be better spent elsewhere (Hymon 1). However, ambition has helped to spark public interest and the recreational, economic, aesthetic, and environmental benefits justify the costs. Revitalization means turning the once “stain” of LA to a beautiful and thriving river that someday everyone will be able to enjoy.

Sources/website links:

http://lariver.org/index.htm

http://articles.latimes.com/2007/feb/02/local/me-riverplan2

http://www.lamountains.com/involved_river.asp

http://folar.org/?page_id=16

“City of Los Angeles :: Los Angeles River Revitalization.” City of Los Angeles River

Revitalization. City of Los Angeles. Web. 29 Feb. 2012. <http://lariver.org/index.htm>.

Hymon, Steve. “L.A. Will Take Its River to a New Level.” Los Angeles Times. Los Angeles

Times, 02 Feb. 2007. Web. 29 Feb. 2012. <http://articles.latimes.com/2007/feb/02/local/me-riverplan2>.

“Los Angeles River | LAMountains.com.” LAMountains.com. Santa Monica Mountains

Conservancy. Web. 29 Feb. 2012. <http://www.lamountains.com/involved_river.asp>.

“River History.” Friends of the Los Angeles River. FOLAR. Web. 29 Feb. 2012.

http://folar.org/?page_id=16.

Katie Peters and Casey Frost are undergraduates in the USC Dana and David Dornsife College of Letters, Arts and Sciences.

October 11, 2011

The LA River: Wouldn’t it be nice if it didn’t smell like steamed broccoli?

Before the construction of the Los Angeles Aqueduct, the Los Angeles River was the primary source of drinking water to every inhabitant of the LA Basin.  However, due to intense flooding in the 1930s, the Army Corps of Engineers erected what became a mortar grave for a once thriving ecosystem.

The LA River is a conundrum in every sense in the word.  The city depends on water for its lifeblood, but the channelization of the river was done with the objective of ridding the city of its rainwater as quickly as possible. This was done as a means of flood protection; however it left only a dusty memory of the pristine ecosystem it once was.  Los Angeles suddenly became dependent on the LA Aqueduct for its drinking supply, a move that would enable Los Angeles to expand into what it has now.

In recent years, the problem of the LA water supply has been exacerbated by severe drought.  In an attempt to restore the natural ecosystem whilst understanding utilitarian needs, multiple agencies in Los Angeles, such as Friends of the Los Angeles River, the Ad Hoc Committee, and the LA DWP, have proposed a “restoration” of the LA river, including a removal of the concrete river bed where possible, and the construction of parks and housing around the river.

In order for the restoration to be successful, Los Angeles must clearly define what they hope to accomplish by restoring the river. Knowing exactly what the river was like pre-1930s is a daunting task.  Many of the species that once inhabited the river, such as grizzly bears and beavers no longer reside in Los Angeles.  In addition, the river’s course has already been so altered by years of channelization that plotting its original course would interfere with infrastructure that is already present in the mega-city of LA. Therefore, restoring the LA River to its natural state would be an unfeasible task. For this reason the aim of the proposed plan is not necessarily to restore, but rather to rehabilitate the existing ecosystem and the surrounding LA community. The goals of the project are to revitalize the river, “green” the neighborhoods, capture community opportunities, and create value.

Revitalizing the river would reduce our dependence on imported water, improve nutrient recycling within the LA River, reduce run-off pollution into the ocean, and improve the aesthetic properties of the river. Los Angeles is a city lacking in parks, but implementing this plan creates green environments available for all Angelenos to use and enjoy.  A rehabilitated LA River would improve the quality of life of residents in Los Angeles by removing a stain on the city and replacing it with a beautiful environment, not to mention the public health benefits associated with this project, such as greater nutrient recycling within the river ecosystem.

As plans lie right now, the restored river would flow year-round.  This is done because the river is fed by tertiary treated water from the Tillman Sewage Treatment Plant.  However, this is far from natural.  In an ideally restored river, the treated water should be injected into an underground aquifer where it can be recharged, and instead let the river capture a natural supply of water.

Critics say that revitalizing the LA River would be too costly, and that expenses are best spent developing neighborhoods in poverty. However, the costs associated with restoring the river are justified, as this would create a safe recreational area able to be used by all. The river flows through every part of Los Angeles, and every Angeleno should be able to enjoy its benefits.

http://www.lariverrmp.org/CommunityOutreach/pdf/03Chapter2-Vision42407.pdf

http://www.environment.ucla.edu/ucpe/blog/article.asp?parentid=2150

http://www.latimes.com/la-me-river12sep12,0,6048358.story

About the authors: Adam Grosher and Connor Jackson are working towards their bachelor degrees in Environmental Studies in the USC Dornsife College of Letters, Arts and Sciences.