Saving California’s Beaches
Jack McHenry
Tamara Black
WRIT 340
11 February 2024
California’s rivers and coastlines are pivotal to its environmental health and economic prosperity. These natural resources support diverse ecosystems, fuel tourism, and provide recreational spaces that are integral to the state’s lifestyle and economy. However, the state’s aggressive pursuit of water management and energy production through damming has led to unintended environmental consequences. While dams have played a crucial role in California’s development by providing essential water resources and hydroelectric power, their construction and operation have inadvertently led to the degradation of coastal ecosystems. This is primarily due to the reduction in sediment flow, which is essential for the natural replenishment and sustainability of beaches.
Dams disrupt the natural flow of sediments downstream, leading to “sediment starvation” at the coast. Normally, sediments flow downstream and replenish beaches naturally. This helps maintain the fragile coastal ecosystems. However, when dams are in place, this natural replenishment does not happen. This lack of sediment contributes to coastal erosion, resulting in the loss of beaches, destruction of habitats, and diminished natural defenses against storms and rising sea levels. The altered flow of sediments affects river and coastal ecosystems, leading to a loss of biodiversity. This includes impacts on fish populations, which rely on specific habitats for spawning, and on wetlands, which are crucial for bird species and other wildlife. Sediment starvation not only impacts the environment but also the economic value and recreational use of these coastal areas.
While dams have provided significant economic benefits, including agricultural irrigation, energy generation, and flood prevention, increased damming has caused sediment starvation endangering one of California largest economic drivers, its beaches. This researcher informs the reader that “The effect is strongest in Southern California, where there are more coastal dams, and also more beach recreation and tourism supporting a billion dollar ocean economy. Griggs found that 50 percent of the sand that should be transported to beaches by Southern California streams gets trapped behind dams — nearly 200 million cubic yards since the 19th century” (Jacobs). Orange County, one of the most well known beach counties, has looked into ways to fix the problem, most notably bringing in more sand. According to the L.A. Times, “About $15.5 million in federal funds will be allocated toward the restoration of Orange County’s beaches and coastline, following passage of a budget bill in Congress last week.” In a desperate attempt to fix their beaches in a quick and easy way, Orange County took what would naturally be a river’s job of natural sediment replenishment into their own hands. While this may have been a viable solution at the moment, it was only a temporary fix. Beaches naturally get washed away over time. “California rivers have historically delivered between 70–85% of the sand naturally supplied to the coastline. This delivery has been greatly reduced by dams, which prevent the sand from getting to the coast and nourishing the beaches naturally; this in turn has resulted in narrowing beaches.” Rivers bring sediment from inland areas to the beaches, cyclically replenishing the beach areas. This is part of the life cycle of a beach. So, this money is essentially being used to fill a constantly emptying hole. Instead, if used in preventing the loss instead of repairing it, these funds could do a lot more good and have a lot longer longevity.
California’s coastlines are not just iconic landmarks; they are crucial to our environmental health, economic prosperity, and cultural heritage. The connection between our inland water management practices, particularly damming, and the health of our coastal environments is more critical now than ever. One pressing factor is the immediate effect on the economy. Out of the 58 counties in California, the “19 coastal counties generated $662 billion in wages and $1.7 trillion in GDP in 2012, which both account for 80 percent of their respective state totals”. These numbers show that roughly 32.8 percent of counties in California make up 80 percent of total GDP. These stats have not changed since 2012. Beaches are the lifeblood of California, making up not only our culture, but our livelihood. It is no surprise that “tourism and recreation is the largest of California’s six ocean-dependent sectors, accounting for 39 percent of the ocean economy’s GDP ($17.6 billion), 75 percent of the ocean economy’s employment (368,000), and 46 percent of the ocean economy’s wages ($8.7 billion)” (NOAA). If beaches continue to diminish at the rate we see now, so will these numbers. People will lose not only the joy of living in California, but also their jobs. California needs to work to change its policies before it is too late.
Dams causing sediment starvation is a large economic problem for California. However, it is not the only problem dams are causing. They also represent dangers to people and the environment. One particularly problematic case is the Oroville Dam in the Sierra Nevada foothills of California. As the tallest dam in the United States, the Oroville Dam has been important to California due to its capacity for water supply and hydroelectricity generation. However, the notorious dam has had significant issues over the years, including one large incident that resulted in the evacuation of 180,000 people. This incident was caused by a significant build up of sediment, blocking the main and emergency spillways. The dam was damaged but the incident was brought under control enough to avoid a major accident. This incident exemplifies the challenges with dam sediment management and the environmental impacts associated with these challenges.
Conversely to the Oroville Dam, after 100 years, several dams on the Klamath River in Oregon are being removed. This represents a move towards restoring natural sediment flow and revitalizing ecosystems. “There’s about 17 to 20 million cubic yards of sediment built up behind the three remaining dams. Through the drawdown process, we expect five to seven million cubic yards of sediment to go downstream.” This quote from Ren Brownell, spokesperson for the Klamath River Renewal Corporation, the entity charged with dam removal, shows the sheer magnitude of sediment dams withhold, and the environmental impacts the removal will have. The Klamath River is a perfect example of a step in the right direction.
By comparing California’s experiences with places like the Pacific Northwest where dam removal has been pursued more aggressively, we can see insights into successful strategies for mitigating similar environmental issues. The adoption of innovative dam design and operation methods that allow for sediment passage are examples of these strategies. This includes modifications to existing structures and consideration of sediment management in the planning of new projects. China has done well in innovating on both of these fronts. “Because of the extremely high sediment loads of the Yellow River, China has innovated more than most other countries in sediment management, and has a rich experiential base upon which to draw.”
(a) Conventional reservoir, which traps incoming sediment, contrasted to alternative configurations for bypass of sediment-laden flood flows around the storage pool: (b) bypass off-stream storage, wherein a diversion dam in the river diverts water to the off-channel reservoir during times of clear flow but does not divert when suspended sediment concentrations are high, and © a sediment bypass channel or tunnel, which during times of high water and high sediment concentrations, diverts flow from the river upstream of the reservoir, passing it around the reservoir and into the downstream channel.
One other very effective sediment management strategy is sluicing. This strategy focuses on the prevention of further sediment build-up, rather than the removal of previously built-up sediment. Due to this, sluicing is best implemented in new projects. “One advantage of this approach is that deposition in the reservoir is minimized and the sediment continues to be transported downstream during the flood season when sediment is naturally discharged by the river. Finer sediments are more effectively transported through the reservoir than coarse sediments… Some previously deposited sediment may be scoured and transported, but the principal objective is to reduce trapping of incoming sediment rather than to remove previously deposited sediment.”
One promising new method might be the solution we hoped for, “To address the problem in a different way, the EPFL team developed a system using submerged water jets to create turbulence that keeps tiny sediment particles in suspension so that they can be carried away through the dam’s water turbines.” This method is one of the easiest to implement due to its simplistic nature. While removing dams entirely would solve the problem and return beaches to their natural size, it is impractical due to the high demand for water and power in California. The benefit of this method allows dams to be altered rather than fully destroyed. With this method dams could continue providing water and power to surrounding areas while still allowing sediment to flow through and replenish our beaches.
Highlight the importance of integrating coastal management with upstream river and dam management through beach nourishment projects and restoration efforts. These initiatives aim to counteract the effects of sediment starvation and coastal erosion. Suggest changes in policy and regulatory frameworks to encourage sediment transport, support dam removal where feasible, and explore alternative water storage solutions. As sediment accumulates behind dams, it can impair reservoir functions and ultimately reduce or eliminate storage capacity, threatening the sustainability of water supply and hydroelectric power generation.
A study done in Puerto Rico shows promising results with the use of an off-stream reservoir. The study states, “Using daily data from streamflow and sediment gages in Puerto Rico indicate that it is possible to exclude between 90% and 95% of the total sediment load from an off-stream reservoir, thereby prolonging reservoir life by a factor of more than ten as compared with an on-channel reservoir on the same river” (Kondolf). Not only would the implementation of this strategy allow drastically more sediment flow to continue its natural course to the ocean, repairing our dwindling beaches, but it would also drastically increase the longevity of reservoir efficiency by keeping capacity higher. This strategy, if implemented on a large scale, could help solve the main two problems associated with dams. By preventing reservoir fill, overall fresh water carrying capacity over time increases. This would be a huge boost towards a less drought plagued state, as well as help support agricultural success. By achieving these two things, in addition to the sediment flow repair effects it would have, off-channel reservoirs would win over the support of the general public as well as farmers. With support from environmental activists, the tourist industry, farmers, and the general public, changes to the damming policy should be quite easy to push for. These measures would help balance the needs for water management, energy production, and environmental conservation. If achieved in enough dams in California, a significant increase to fresh water supply, hydroelectric power, and natural sediment flow could be achieved. Not only would these benefits do well for the state on their own, they would also help save taxpayer dollars from going to beach repair programs.
Moving forward as a state California needs to use a multitude of methods. Damming is a complicated problem and therefore requires a complicated solution. With the use of off-stream reservoirs as a main solution, due to their high efficiency, California should see immediate improvement. The use of other methods, including angled dams and water jets would be implemented in areas where dam and reservoir replacement would be inefficient or impossible. While it is not a perfect solution California’s beaches will see a drastic improvement if such policies take effect.
The essay reaffirms the critical need for a balanced approach to damming and coastal management in California. While recognizing the importance of dams, it emphasizes the urgent need to address their environmental impacts, particularly on the state’s coastlines. Encourage policymakers, environmental organizations, and the public to consider the long-term environmental and economic benefits of adopting sustainable practices. These practices should aim to protect and restore California’s coastlines, ensuring the preservation of these vital natural resources for future generations.
Works Cited
Adkins, Jeffery, et al. “The National Significance of California’s Ocean Economy.” NOAA Office for Coastal Management, NOAA, 2015, coast.noaa.gov/data/digitalcoast/pdf/californi a-ocean-economy.pdf.
California State Parks, State of California. “Sand Loss behind Dams.” CA State Parks, dbw.parks.ca.gov/?page_id=29356#:~:text=California%20rivers%20have%20historically%20delivered,has%20resulted%20in%20narrowing%20beaches. Accessed 13 Feb. 2024.
Kondolf, G. Mathias. “Sustainable Sediment Management in Reservoirs and Regulated Rivers: …” AGU Advancing Earth and Space Sciences, agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013EF000184. Accessed 13 Feb. 2024.
Miller, Josh. “Dam Removal on the Klamath River.” Life Depends on Rivers, www.americanrivers.org/dam-removal-on-the-klamath-river/#:~:text=The%20dams%20along%20the%20Klamath,in%20the%20summer%20of%202024. Accessed 13 Feb. 2024.
Neumann, Juliet Grable and Erik. “Researchers, Tribes, Residents Prepare for a Century of Sediment Released from the Klamath Dams.” Opb, OPB, 16 Jan. 2024, www.opb.org/article/2024/01/05/klamath-falls-oregon-dam-removal-sediment-karuk-tribe/#:~:text=%E2%80%9CThere’s%20about%2017%20to%2020,of%20sediment%20to%20go%20downstream.%E2%80%9D.
