Recovery of the San Gabriel River: A Place Filled with Life and Beauty

In 2013, the Los Angeles-Area Regional Water Quality Control Board rated the 2.5-mile stretch of the San Gabriel River East Fork an “F” for violating the agency’s standards for trash.

The San Gabriel River is located in eastern Los Angeles County and flows 93 km through Los Angeles and Orange Counties California. It is an urban waterway that flows from the San Gabriel Mountains to the Pacific Ocean near Seal Beach. 

Additionally, the San Gabriel River has a basin size of 689 sq ms, which makes it the largest watershed within Southern California’s San Gabriel Mountains.

Its West, North, and East Forks of the San Gabriel River are an important source of clean drinking water for close to 4 million people in the San Gabriel Valley and southeast L.A. County cities.

The river is also a popular recreation spot for those hoping to swim, picnic, hike, fish, or camp along the river canyons.

As identified by the Forest Service, the San Gabriel River is an area of high ecological significance because of its ideal habitat for approximately 3000 different land and marine animals. Many of these organisms are native species threatened or endangered species.


The San Gabriel River was once a “rich lowland ecosystem” home to many species of fish, as well as the water source for thousands more animals living in the San Gabriel Mountains of which 160 are now rare, threatened , or endangered species. The abundance of native fish in the river, such as the steelhead trout and the arroyo chub, makes it an important habitat with high significance. 

Unfortunately, due to irrigation development, damming, and channelization for flood control, these developments have contributed to the near-extinction of several species of fish, including the steelhead trout. 

On top of that, increased urbanization led to the loss of a vast majority of original wetlands, leaving less than 2,500 acres remaining from what was originally 392 million acres of wetlands.

San Gabriel Circular Economy Solutions Mumbai India Environmental NGO Earth5R

Fishing in the East Fork San Gabriel River (Typepad)

With the end of the drought, the California Department of Fish and Wildlife (CDFW) has started to restock Crystal Lake in Los Angeles Country with rainbow trout to repopulate the river after years of drought which led to deteriorating water quality and shallow water levels.

As a result, rainbow trout comprises the majority of fish populations and a total of 79 rainbow trouts were caught and measured by the California Department of Fish and Game for their electrofishing surveys.


Along with the Los Angeles River, the San Gabriel River is a major influence in the development of Los Angeles. From around the twentieth century, the San Gabriel River started to have a huge impact on the cultural and economic development of Los Angeles due to the discovery of 3 special ingredients: gravel, sand, and rock.

It is estimated that over one billion tons of aggregate have been mined from the San Gabriel River.

The mining operations resulted in severe consequences to the environment.

San Gabriel Solutions Circular Economy Mumbai India Environmental NGO Earth5R

A rock quarry found in the city of Irwindale near the San Gabriel River (The Los Angeles Public Library)

Around the mid-1900s, the successful creation of the Santa Fe Dam (92ft. tall) and Whittier Narrows Dam (56ft. tall) as flood control basins of the lower San Gabriel River transformed the river into a symbol of strong will for eliminating flood risk within Los Angeles. 

To minimize flood damage to nearby urban areas, the Santa Fe Dam was constructed to hold more than 45,000 acre feet of water and release it at a rate of 41,000 cubic feet per second which can decrease the amount of stored water and thereby reduce the possibility of a flood occurring.

Hopeful for the future, many organizations held visions of restoration for the San Gabriel River that remakes it as a healthier and greener river in the twenty-first century.

Although the watershed is such an important symbol of Los Angeles, it faces a major threat of pollution that must be addressed.


When gold was first discovered in the San Gabriel River in the 1840s, hundreds of gold seekers started arriving in hopes of discovering gold. What many of them discovered there was indeed gold and from 1859-1862, Wells Fargo alone shipped $15,000 worth of gold per month. 

As a result of the extensive gold exploration, settlements and towns such as the town of Eldoraville, with an estimated population of 1,500, were established along the upper and lower San Gabriel River.

As settlements expanded, gold seekers started mining gold with more advanced and efficient methods. In the 1850s, the use of hydraulic mining to separate gold from river gravel was one of the more “efficient” ways in which gold-seekers used to mine gold. 

By the mid-1880s, it is estimated that 11 million ounces of gold (worth approximately US$7.5 billion at mid-2006 prices) had been recovered by hydraulic mining in the California Gold Rush.

However, the use of hydraulic mining brings along a significant consequence on the ecosystem.

San Gabriel Recovery Circular Economy Mumbai India Environmental NGO Earth5R

 Hydraulic Mining (USGS)

Hydraulic mining is the process in which “high-pressure jets of water” are used to dislodge rocks and sediment in order to extract gold which creates drastic consequences to the environment. Reported by historian Hubert Howe Bancroft, an 8-inch hydraulic monitor can shoot 185,000 cubic feet of water with a velocity of 150 ft per second into the river.


The use of mercury often assisted hydraulic mining and resulted in the poisoning of groundwater in the San Gabriel River. Consequently, the ecosystem was damaged due to the large amounts of mercury within the river, which poisoned many of the native fish. 

Samples collected from the Common Carp and the Largemouth Bass species, belonging to the Puddingstone Reservoir, were detected to contain means of 41ppb and 296 ppb of mercury respectively. 

As a result of studies such as this, many fish consumption advisories were created in California to address the threat of human consumption of mercury-poisoned fish.

The native fish were an important part of the ecosystem and the poisoning of mercury took a huge toll on their populations.


Furthermore, hydraulic mining also resulted in the damage of agriculture and an increase of erosion to the land. 

Due to hydraulic mining, a total of about 211 million cubic yards of residue were dumped into the river, causing a build up of the riverbeds which ultimately led to later flooding. Floods led to tragic effects on both the ecosystem and the residents nearby. 

Additionally, erosion was also another factor to floods. Without enough soil to absorb water, increased erosion prompted more floods and ultimately, caused one of the costliest disasters in Los Angeles: the massive Los Angeles flood in 1938

This tragedy led to an estimated 70$ million in damage, 5,600 destroyed homes, and the death of around 114 people.


Due to both the huge amounts of runoff and discharge of several major wastewater treatment plants (with the largest being the Los Coyotes plant) the San Gabriel River is in danger of pollution.

Not only does the San Gabriel River face pollution from wastewater treatment plants, but also pollution from the heavy commercial and recreational activities in its area. 

Because of its reputation as a popular scenic route, more than 1.5 million people visit the river annually and many leave behind waste and trash that negatively affect the ecosystem and contribute to the pollution of the river.

Furthermore, the many storm drains that drain into the San Gabriel River also bring along chemicals, pesticides, plastics, fertilizers, and more. All of which degrade the water quality and caused an exceedance of approximately 11 samples in which the San Gabriel River was tested below the WQO standards between 2004 and 2012 for levels of dissolved oxygen.

San Gabriel Circular Economy Plastic Pollution Mumbai India Environmental NGO Earth5R

Trash left by homeless encampments along the San Gabriel River Trail (Pasadena Star-News)

Through the disposal of trash and waste into the river, hundreds of homeless encampments on the San Gabriel Riverbed have also contributed to the rising pollution and bacteria in the River.

As a result, for many years, many organizations have consistently pointed to the East Fork of the San Gabriel River as one of the more polluted freshwater rivers in the state.


Plastic debris among the San Gabriel River from storm drains and recreational activities in the area are negatively affecting the ecosystem and biodiversity both in and around the San Gabriel River. In 2013, plastic made up 13% of the national municipal waste stream.

In near coastal waters off the San Gabriel River, the mass of plastic less than 5 mm was found to be 60% of the mass of the associated zooplankton.

Plastics can release toxins into the surrounding soil, which seeps into nearby or underground water sources and results in a variety of potential consequences to our water supply.

California’s waste stream consisted of over 9% plastic by weight in 2003 and contributed about 3.8 million tons.

Plastic Pollution in San Gabriel River – Together We Fly (Kevin Zheng)

Research by Orange County Coastkeeper found that in the San Gabriel River, microplastic was abundant in nature and that there were “hundreds of thousands of microplastics per sqm of water.”

Microplastics ingested by fish that contain pollutants and chemicals can pose a huge threat to human safety. These chemicals can accumulate to up to 1 million times the concentration of the chemical in the surrounding water.


Contamination in the groundwater of the San Gabriel River also existed as a result of improper dumping of industrial wastes and chemicals. 

Based on annual reports by River Watermaster, an average of 35,700 af/yr groundwater is exported from the San Gabriel River Basin. 

Since many of the water resources in Los Angeles are sustained by the underwater reservoirs from the San Gabriel River Basin, contamination in those reservoirs can pose a dangerous threat to human health and safety among the residents and locals.


In 2016, the TCE (Trichloroethylene) concentration in the wells around the basin averaged at 21 µg/L when the Maximum Contaminant Levels (MCL) set by the U.S EPA is 5 µg/L.  TCE is carcinogenic to humans and poses health hazards. 

San Gabriel River Pollution Circular Economy Mumbai India Environmental NGO Earth5R

2011 Groundwater quality study (U.S. Geological Survey and the California State Water Resources Control Board)

Due to groundwater contamination in the San Gabriel Valley, the USEPA has listed 4 areas of the San Gabriel River Valley as part of its National Priorities List. 

Since the groundwater located in these areas affects the many cities of Los Angeles County, contamination of these areas, such as detections of VOC 1, and the inorganic chemical perchlorate has prompted the installation of several clean projects, called Operable Units, to combat this issue.


One of the huge contributors to the inaction towards the removal of pollution in the San Gabriel River was the lack of funds. 

Although in 1959, action was taken to combat the rapid rate of erosion through the deposition of 225,000 cubic yards of material between the Anaheim Bay Jetty and the Seal Beach pier, insufficient funding continued to limit the amount of actions taken by organizations towards addressing the growing concern of pollution and erosion.

Insufficient funds forced organizations, such as the U.S. Forest Service, to be helpless towards the growing danger of pollution and erosion in the river as they continued to remove as much trash as they can with their best efforts. 


Faced with this imminent danger, the U.S. Forest Service and many other organizations have been pushing for actions regarding the removal of waste from the rivers. 

  • In 2014, Barack Obama designated 342,177 acres of existing “Federal land” to the Forest Service Management, as the San Gabriel Mountains National Monument. The Monument generated $5 million from donations and also prompted other organizations and agencies to also start donating to the cause for protecting our rivers.
  • Coca-Cola has donated a total of $900K towards supporting the San Gabriel River, specifically that of “trash pickup, ecological restoration, and visitor services,” in honor of the one year anniversary for the San Gabriels Mountains National Monument.
San Gabriel Sustainability Circular Economy Mumbai India Environmental NGO Earth5R

“Proposed Legislation” to expand the San Gabriel Mountains National Monument (Sierra Club Angeles Chapter)

With sufficient funding, the administration and international organizations were able to take action against the pollution within the San Gabriel River through countless projects, such as:

  • East Fork Project, with the mission of restoring the ecosystem and improving recreational quality in the 2.5-mile section of the San Gabriel River (East Fork).
  • Safe Clean Program for both the Upper Section and Lower Sections of the San Gabriel River, were also established to raise $250 million dollar annually to fund projects addressing the pollution within the San Gabriel River. 


  • After storms, a horrifying amount of plastics often wash up at the lower section of San Gabriel River (Seal Beach). To combat this disaster, cleanup efforts have been organized monthly by nonprofit organizations such as Save Our Beach to remove trash from Seal Beach before it washes into the ocean.
  • After storms, a horrifying amount of plastics often wash up at the lower section of San Gabriel River (Seal Beach). To combat this disaster, cleanup efforts have been organized monthly by nonprofit organizations such as Save Our Beach to remove trash from Seal Beach before it washes into the ocean.
  • Additionally, a grant of $160K is currently being used to install catch basins to capture pollutants and reduce the amount of trash swept into the San Gabriel River.
  • In honor of National Public Lands Day, the U.S. Army Corps of Engineers Los Angeles District partnered up with the Whittier Narrows Nature Center Associates and the LA Country to host a cleanup event that consists of more than a hundred volunteers who managed to dispose of more than 6,500 pounds of garbage.
San Gabriel Waste Cleanup Circular Economy Mumbai India Environmental NGO Earth5R

Volunteers participating in the cleanup effort (Los Angeles Times)

  • Another initiative done by the Los Coyotes Middle School was a runoff project to reduce runoff so there is less amount of trash that ends up in the San Gabriel River. Installing thicker bars over the 13 storm drains of the school were just some of the ways in which this Middle School took to combat the issue of pollution within the river.


Although in 2019, Heal the Bay, a U.S. environmental advocacy non-profit organization, rated the San Gabriel River as 100% green, the issue is far from over.

Despite the attempts by the community and the administration to solve the issue of pollution, huge amounts of trash continue to wash up on the shores of the San Gabriel River. 

During recent storms, the Times reported that the San Gabriel River deposited “a heap a half-mile long, 20 feet wide and almost 3 feet high” of garbage.

Heal the Bay’s stormwater report shows six years of shockingly minimal progress in cleaning up Los Angeles’ storm-water.

San Gabriel Waste Pollution Circular Economy Mumbai India Environmental NGO Earth5R

Trash on Seal Beach after a storm (Orange County Register/SCNG)

High levels of bacteria are also extremely evident after storms. The state standard MPN for enterococcus bacteria was 104, however, results after a storm show that the MPN for the San Gabriel River was popping off the charts with a score of 4,374.

The continued policies by the administration towards providing a flood control system through the use of extensive storm drain networks have also continued contributing towards the large amounts of trash swept into Seal Beach after storms. Within the waterways, the speed of the storm flows ranges up to 20 feet per second in the river .

The San Gabriel River received drainage from 689 square miles of eastern Los Angeles County.

Although the community and the administration have succeeded in temporarily removing trash from the San Gabriel River, their efforts are insignificant compared to the larger picture in the vast blanket of trash that appears on the shores of Seal Beach after storms. 

Solving the significant problem requires a much more effective plan of eliminating waste disposal: circular economy.


Our current linear economy of extracting raw goods, production, distribution, consumption, and ultimately creating waste, is the leading factor towards the amount of trash that appears on the shores of Seal Beach. 

With all the money spent by the administration, the efforts will not be sustainable without the contribution from the local communities. Replacing our current economy with that of a circular economy is the key to reducing the amount of trash swept onto beaches. 

Efforts done by Earth5R towards establishing a circular economy, such as the Recycle Training At Palghar, and Beach Clean Up at Chennai, has already proven effective towards eliminating waste disposal and raising awareness of the circular economy to more people. 

Recycle Training at Palghar (Earth5R)


  • Through collaboration with churches and interactive workshops, more locals and residents of the San Gabriel River can be aware of the need for a circular economy to address the threat of pollution to their ecosystem.
  • Local citizens can act as a citizen scientist to help authorities by reporting the pollution they came across in their area such as illegal dumping, plastic trash, color of the water bodies, etc. 
  • Through recycling and reusing goods instead of disposal, utilizing a renewable or organic source for fertilization of crops instead of chemicals, and minimizing the use of single-use products, trash, and pollution that wash up on the shores of the San Gabriel river can be reduced. 

Through these simple actions, everyone can contribute towards the reduction of trash in the rivers and long lasting sustainable practices by the locals will help in keeping the river clean for generations to come.

Reach out to Earth5R to know more about solving environmental issues by creating circular economy based sustainability projects.


Earth5R is an environmental organization from India with its head office at Mumbai. It works with the NGO sector, Companies and helps them conduct environmental corporate social responsibility (CSR) programs across India. Earth5R specializes in circular economy based projects. Earth5R also offers short term and long term environmental courses.

Earth5R is conducting large-scale online training on COVID 19 Coronavirus prevention, response, management, and self-sustainability. These trainings are conducted on digital platforms in regional languages across India and other countries.

Earth5R’s Global Sustainability Hub is a cross-sector and cross-country collaboration in pursuit of UN Sustainable Development Goals. It is an excellent opportunity for governments and the private sector to engage with communities, use Sustainability-based models to drive economic changes, and create social and environmental impact.

Reported by Claire Hsu, edited by Shafa Azzahra

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