The LA River From Concrete Ditch to Urban Oasis

Written by BlackbirdGo November 20, 2018
The History

The Los Angeles River is often depicted in film as a wasteland, a concrete-lined channel stretching from Long Beach through downtown LA and up north into the San Fernando Valley. It was the dry, garbage-strewn filming location of the chase scene in Terminator 2, along with the Thunder Road race scene in Grease. But between downtown LA and the Valley, a stretch of river running through the Glendale Narrows looks utterly unrecognizable compared to the rest of the river. Instead of concrete, the river is lined with rocks and trees; little islands have formed that are dense with verdant vegetation. This is more or less what the entire river once looked like before most of the riverbed was lined with concrete.

The stretch that runs through the Glendale Narrows was left unpaved due to challenges the engineers faced when they paved the rest of the LA River. Visitors and newcomers to Los Angeles may wonder why the river is paved at all. Even some locals, like the environmental advocacy group Friends of the LA River, want to see the entire river stripped of concrete. But without that pavement, much of the city would have been washed away many times over.

It may be difficult to picture the LA River in a flooded state, especially during a dry year. Between 2017 and 2018, Los Angeles received fewer than five inches of rainfall. Droughts were widespread across the entire state. US Forest Service crews struggled to contain a staggering number of wildfires across California last year—nearly 9,000 separate fires that burned a total of 1.2 million acres. But every so often, the weather changes abruptly. In the winter of 2004-2005, the city received 37.25 inches of rainfall, more than double the annual average. All that water needs a place to go, and, without the pavement along the riverbed, that place would be its natural floodplain: the residential neighborhoods and industrial areas that have come to line the river.

When the River Ran Free

Historically, the LA River has been wild and uncontrollable. It stretches 51 miles from its headwaters in the San Gabriel Mountains to the delta where it meets the Pacific. The Tongva tribe that inhabited the region for thousands of years knew enough about the river to build their homes away from the floodplain, but European settlers lacked the foresight and the historical knowledge of the region that the Tongva had.

Over the ensuing years, the river flooded many times, often with disastrous results. The Los Angeles River actually changed directions due to flooding in the 1800s, switching from its historical westbound course into Santa Monica Bay to its current south-bound route into San Pedro Bay.

Numerous buildings and bridges were swept away by flooding in the early twentieth century. The paving project was initiated by the Army Corp of Engineers after a series of devastating floods in 1914, 1934, and 1938 caused a combined 193 deaths and over one billion dollars in property damage.

Paving the river was an engineering feat. It took 22 years, 3.5 million barrels of concrete, and 147 million pounds of steel. The concrete riverbed, along with the multiple flood channels that were constructed along its path, undoubtedly prevented more death and destruction by the river’s unpredictable floods and uncontrollable waterflow. But some conservationists feel that that salvation has come at a price.

The Cost of Urbanization

The loss of habitat has been one of the most devastating effects of the river’s paving and the subsequent development along its banks. The California Coastal Conservancy estimates that nearly 100% of the region’s wetland habitat and up to 95% of its underwater riverbed habitat have been decimated. Numerous species of benthic macroinvertebrates (BMIs) that are considered indicators of good water quality have struggled to survive, largely because of human development and contamination along the river.

Fish and aquatic invertebrates aren’t the only creatures affected by the river’s deterioration; humans have also been negatively impacted by the poor water quality. The water used to be considered unsafe for any form of recreation. Bacteria like enterococcus and e. coli have historically been found in the LA River at levels that often exceed federal safety levels. Experts believe these bacterial contaminations were caused by citywide water runoff, septic leaks, and municipal wastewater collection system runoff.

In lab reports from five river locations compiled between 2003 and 2004, samples failed to meet set water quality standards up to 50% of the time. The water samples were tested for pH, cloudiness, dissolved oxygen, total dissolved solids, water temperature, and water nutrient levels.

Things seemed grim for humans and animals alike. But, after years of negotiation over the future of the river, something changed. Conservation groups and local governing bodies began working together on a new plan for the river.

Rebirth of the LA River

The City of Los Angeles formed an ad hoc committee in 2002 to study the feasibility of revitalizing the LA River. That committee eventually became the LARiverWorks team, a permanent addition to the Mayor’s Office. The team has already made remarkable progress working with municipal agencies, private organizations, and residents. Prior to 2013, the river was deemed unsafe for recreational activities, including fishing and kayaking, but these activities are now common at various points along the river.

According to the LARiverWorks team, “The Revitalization Master Plan...may [also] include the removal of concrete in portions of the river. Any changes made to the channel will be made to maintain or enhance safety during peak flow events. Any materials removed from the LA River will be disposed or recycled in an environmentally sensitive manner.”

The team’s ultimate goal is to make the entire river safe for recreation while also restoring the ecosystem along the LA River. This includes improved water quality, enhanced floodwater storage, reintroduction of riverbank vegetation, and construction of riffle pools with fish ladders to support endangered native steelhead trout .

In addition to improving the river habitat, the LARiverWorks team plans on developing outdoor classrooms for local schools, building new parks and greenways, and improving access to bike paths and pedestrian trails along the river. In total, thirty-two miles of riverbank will eventually form one continuous park. The hope is that improved access—along with increased recreation opportunities and a cleaner environment—will make the river a destination for residents and tourists, instead of an eyesore.

The team’s vision has already caught the eye of architect Frank Gehry, who was hired by LA County earlier this year to implement the River Revitalization Master Plan. The specifics of Gehry’s vision for the river remain somewhat secretive, but, based on the advances that the city has already made, things will only continue to improve for the humans and animals that call Los Angeles home.

Disclaimer: Keep out of reach of children. For use only by adults 21 years of age and older.