Friday, February 7, 2025
47.3 F
Roseville

Clear Lake water quality report recommends rehabilitation strategy

UC Davis Tahoe Environmental Research Center Outlines Clear Lake Water Quality Issues

The water quality of Clear Lake – California’s largest natural freshwater lake – suffers from low-to-no-oxygen conditions that contribute to harmful algal blooms (HABs) and other issues, according to a report from the UC Davis Tahoe Environmental Research Center and the U.S. Geological Survey.

Clear Lake has long suffered from environmental challenges associated with mercury contamination, high nutrient levels, low dissolved oxygen and HABs, which threaten aquatic and human health and the community’s cultural, recreational and economic activities.

Clear Lake and Mt Konocti

Primary causes

The report, submitted to the Blue Ribbon Committee for the Rehabilitation of Clear Lake, outlines the primary causes of deteriorating water conditions at the 63-square-mile lake. It also applies newly developed predictive tools to test restoration strategies and offers actionable recommendations. These include installing a hypolimnetic oxygenation system, a technology that has been used nationwide and in California to enhance oxygen levels at the lake bottom.

Low-to-no-oxygen, or anoxic, conditions near the lake bottom are created by seasonal temperature stratification, where a warm layer of water on top of the lake prevents oxygen from reaching the bottom.

“This anoxic bottom layer is triggering the bad mechanisms in the lake,” said Alicia Cortés, lead UC Davis TERC project scientist for the Clear Lake project. “These conditions cause lake sediments to release nutrients – particularly phosphorus – which can trigger adverse outcomes like HABs. Low oxygen may also harm fish habitat or produce methylmercury – a highly toxic form of mercury.”

Hypolimnetic oxygenation systems

To address these challenges, TERC recommends implementing hypolimnetic oxygenation systems. These systems aim to enhance oxygen levels in deeper waters to reduce the release of phosphorus from the sediments. This can potentially reduce HABs, enhance fish habitat, reduce methylmercury production and improve overall aquatic health. The report recommends the Oaks Arm, the smallest arm of the lake frequently affected by HABs and mercury contamination, as the installation site for a prototype system.

Monitoring Clear Lake

For the report, TERC researchers partnered with the USGS to conduct a multi-year study to understand the dominant processes in Clear Lake and its watershed that are diminishing water quality.

“Clear Lake is highly dynamic, with strong currents that quickly move particles between its basins and frequent mixing events that alter the vertical distribution of temperature, oxygen, nutrients and harmful algal blooms,” said Alexander Forrest, interim director of TERC and a UC Davis professor in the department of Civil and Environmental Engineering. “These water movements need to be accounted for to make any rehabilitation strategy feasible and sustainable in the long run.”

Clear Lake

To understand these complexities, TERC researchers developed a continuous and multidisciplinary monitoring program, with measurements collected every hour for five years. Researchers installed sensors to track water temperatures, oxygen levels and real-time meteorological conditions. TERC researchers also collected hundreds of water samples to quantify nutrients and phytoplankton concentrations, including HABs, and created a high-resolution bathymetry map of the lake bottom.

Researchers at USGS quantified nutrient and sediment loads entering the lake from the watershed via streams. This is a crucial component of understanding the full system that can influence water quality.
These on-site measurements were essential to developing predictive models for Clear Lake and its watershed. These models help reveal the processes degrading water quality. They show how the lake and watershed respond to changing environmental conditions and future restoration strategies, and they help inform management.

Clear Lake support

TERC received a $1.1 million grant from the California Natural Resources Agency to support the planning and permitting phase for a prototype of the hypolimnetic oxygenation system and for community outreach.

This funding will also support real-time, on-site dissolved oxygen measurements near the lake bottom in the Oaks Arm.

The 15-member Blue Ribbon Committee for the Rehabilitation of Clear Lake was created by state legislation in 2017 to propose effective solutions to the decline of water quality at the lake. It includes representatives from local Indigenous tribes, Lake County, UC Davis and the Central Valley Regional Water Quality Control Board. Four members appointed by Lake County have expertise in agriculture, economics, environment and public water supplies.

The UC Davis Tahoe Environmental Research Center remains dedicated to conducting rigorous research and fostering environmental stewardship of California’s prized natural resources. Through continued collaboration and innovation, TERC envisions a future where Clear Lake thrives again.



Brighter Side

Trending

Bio-identical hormone replacement therapy

As we age, we approach the "pausal" years. For women, it's known as Menopause. For men, it's known as Andropause. During these transitional times in life, it's as if the sex glands go into retirement and there can be a lot of changes,

Placer Conservation Authority takes step toward securing 4,245 acres of land easement acquisitions north of Lincoln

Auburn, Calif. - Approximately 4,245 acres of prime farmland, natural open space and environmental resources north of Lincoln is a step closer to being secured in perpetuity as part of the Placer County Conservation Program.

Boot Juice and Blü Egyptian in Auburn at Foothills Fillmore Feb 22

Auburn, Calif.- Keep Smilin' Promotions is bringing the much sought after Boot Juice to the Foothill Fillmore. The co-billed event also includes Blü Egyptian which has been described as "somewhere where Jimi Hendrix, Jerry Garcia, Joe Satriani & Buckethead are all infused in a Talking Heads state of mind."

Rocklin Unified and Rocklin Teachers Professional Association reach tentative agreement

Rocklin, Calif. - The Rocklin Unified School District (RUSD) and the California School Employees Association (CSEA), Chapter #773, are pleased to announce a tentative agreement for the 2024-25 academic year.

Placer County takes action to preserve Vista Ranch

Lincoln, Calif. - A 279-acre property of blue oak woodlands along the south shore of Camp Far West Reservoir and the Bear River north of Lincoln is a step closer to being added to the Placer County Conservation Program.

Topics

Bio-identical hormone replacement therapy

As we age, we approach the "pausal" years. For women, it's known as Menopause. For men, it's known as Andropause. During these transitional times in life, it's as if the sex glands go into retirement and there can be a lot of changes,

Placer Conservation Authority takes step toward securing 4,245 acres of land easement acquisitions north of Lincoln

Auburn, Calif. - Approximately 4,245 acres of prime farmland, natural open space and environmental resources north of Lincoln is a step closer to being secured in perpetuity as part of the Placer County Conservation Program.

Boot Juice and Blü Egyptian in Auburn at Foothills Fillmore Feb 22

Auburn, Calif.- Keep Smilin' Promotions is bringing the much sought after Boot Juice to the Foothill Fillmore. The co-billed event also includes Blü Egyptian which has been described as "somewhere where Jimi Hendrix, Jerry Garcia, Joe Satriani & Buckethead are all infused in a Talking Heads state of mind."

Rocklin Unified and Rocklin Teachers Professional Association reach tentative agreement

Rocklin, Calif. - The Rocklin Unified School District (RUSD) and the California School Employees Association (CSEA), Chapter #773, are pleased to announce a tentative agreement for the 2024-25 academic year.

Placer County takes action to preserve Vista Ranch

Lincoln, Calif. - A 279-acre property of blue oak woodlands along the south shore of Camp Far West Reservoir and the Bear River north of Lincoln is a step closer to being added to the Placer County Conservation Program.

Wells Fargo Bank in Roseville on Douglas Blvd

Wells Fargo Bank on Douglas Blvd in Roseville. Lobby hours are Mon-Fri 9:00 AM - 5:00 PM, Sat 9:00 AM-12:00 PM. Closed on Sundays.

Ultimate Staffing in Roseville

Ultimate Staffing in Roseville. Employment agency that places temporary, temp-to-hire and direct hire positions.

Sutter Imaging Roseville Parkway

Sutter Imaging Roseville Parkway. Offering a range of powerful diagnostic tools, including ultrasounds, MRIs and X-rays.

Related Articles

Local Spotlight

California Recovery Center in Roseville offers treatment for substance abuse and mental health

California Recovery Center (CRC) is a treatment provider for adults with substance abuse and mental health condition, located in Roseville and serving the greater Sacramento region.

Paul Black’s Solar Panel Cleaning in Roseville serving the region for over 30 years

Roseville, Calif. - Money-saving solar panels in Roseville, Rocklin and throughout South Placer County have become ubiquitous From new residential solar communities continue to big business and after market installation, solar seems to be a smart choice to shred those high monthly electric costs.

Sacramento Naturopathic Medical Center emphasizes the use of prevention and natural therapeutics

Sacramento Naturopathic Medical Center is a professional primary care natural medicine committed to helping all people reach their full potential – mind, body and spirit.