Beavers Make Good Neighbors

Restoration



23
Mar

Beavers Make Good Neighbors

Much like when tech money reshapes an historical neighborhood, a beaver’s move downtown can cause the locals to worry. In Napa, the animals’ sprawling waterfront complexes create worrying pools along the riverbank, while the native cottonwoods are whittled down and threaten landowners’ roofs. It seems destined that two species known for their environmental engineering would struggle to live in unison. However, municipalities like Napa and Martinez in Contra Costa County have learned to live with their beavers, and the upcoming California Beaver Summit aims to set the record straight. “Our approach is hands-off,” says Jeremy Sarrow, a resource specialist with Napa County Flood Control and Water Conservation District, describing the county’s tack toward managing beaver dams built along inhabited waterfronts....
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23
Mar

Sediment Paparazzi

As the Estuary faces drowning marshes due to rising seas, people want to see action – acres saved, walls built, marsh mice whisked to safety after crawling to the tip of the tallest gumplant. In terms of action, “sediment monitoring” doesn’t come immediately to mind. Monitoring is something you do after all the action is over, isn’t it? And as for “sediment,” well what’s all the fuss over some dirt and mud? In fact, there is quite a fuss. The Bay region has a sediment management strategy and a sediment monitoring and modeling strategy, and later this month it will have a new sediment supply and demand analysis. Indeed, six different workgroups of Bay scientists, managers, and regulators are now...
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01
Mar

As agencies wrangle over how best to protect the Delta’s dwindling native fish species, researchers want to see more consideration to the needs of the estuary’s birds.

 “If we want to restore the ecology of the Delta, we can’t just be looking in the water,” says Kristen E. Dybala of Point Blue Conservation Science. In a paper published in San Francisco Estuary and Watershed Science, Dybala and two co-authors make the case that “birds and their habitat needs are often not addressed in science syntheses, conservation planning, and large-scale restoration initiatives in the Delta.” While some birds use the same sloughs and channels that support such high-profile fishes as Chinook salmon and Delta smelt, other bird species rely on habitat types that fringe the Delta’s waterways. Indeed, while general habitat restoration in the Delta can provide multiple benefits for humans, fish and many birds, the authors observe...
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01
Mar

Filling significant recently identified gaps in monitoring spring-run Chinook is critical to protecting these threatened Central Valley salmon.

“There’s no way we can manage them for recovery if we don’t understand the biological processes that govern their dynamics through time and space,” says UC Santa Cruz/NOAA salmon expert Flora Cordoleani, lead author of a study reported in the December 2020 issue of San Francisco Estuary and Watershed Science. Cordoleani and colleagues identified the monitoring gaps while building a model of the spring-run Chinook life cycle. The model accounts for three self-sustaining populations of these at-risk fish, assessing survival of key life stages (eggs, fry, smolts and adults) as well as in key habitats (natal creeks, the Sacramento River, floodplains in the Sutter and Yolo bypasses, the Sacramento-San Joaquin Delta, and San Francisco Bay). “It’s a complex model, and...
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18
Nov

Current estimates of young salmon lost to the south Delta pumps are based on a smattering of studies from the 1970s and should be updated, according to a new analysis.

“They don’t represent current operations,” says Ukiah-based consultant Andrew Jahn, lead author of the analysis reported in the September 2020 issue of San Francisco Estuary and Watershed Science. Current operations at the State Water Project (SWP) and the Central Valley Project (CVP) can reverse flows in the Old and Middle rivers, diverting salmon on their way to the ocean towards the projects. Existing salmon loss estimates also fail to account for a likely Old River hotspot for predators, drawn to the influx of salmon and other fish near the two water projects. Evidence of this hotspot lies in the numerous acoustic tags from young salmon to be found in the sediment, which were presumably defecated by striped bass, as well as...
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18
Nov

Fish passage structures can be improved for the benefit of multiple species, if they are designed to account for differences in behavior, physical ability and size, according to a new literature review.

Historically, most fish passages have been designed to help native salmon return to their upstream habitat and spawning grounds, with little consideration for other migrating species such as sturgeon and lampreys. “There is an assumption that if you just build a fish passage structure, fish will go thorough it, but that is not always the case,” says Department of Water Resources fisheries biologist Zoltan Matica, who conducted the review. “The challenge is to understand that this isn’t only a physical barrier, it can be also a mental barrier.” For example, some species that engage in schooling behavior, such as shad, may refuse to even enter a structure if it limits them to passing one at a time. According to the...
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12
Nov

Science-in-Short ~ Aquatic Weeds Podcast

Wall-to-Wall Sampling of the Delta’s Aquatic Weeds Via Remote Sensing, an interview with Shruti Khanna.  In this episode of the podcast, Estuary News reporter Daniel McGlynn talks to Dr. Shruti Khanna, a senior environmental scientist at the California Department of Fish and Wildlife. Their conversation focuses on Khanna’s use of remote sensing technology to study the Sacramento-San Joaquin Delta. Specifically, Khanna analyzes and processes remote sensing data, or high- resolution images collected by sensors mounted on aircraft, to study invasive plant species growing in Delta waterways. Researchers also use remote sensing to study the Delta’s water quality, fish populations, and overall change. While remote sensing will never replace on-the-ground research, the massive data set produced by collecting large-scale images over...
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28
Sep

Science in Short ~ Fish Podcast

David Ayers: How Fish Interact with Wetlands Topography  In this podcast, Estuary News reporter Alastair Bland and UC Davis PhD student and fish researcher David Ayers discuss the Sacramento-San Joaquin Delta, its fish, its marshlands, its flows, and its future. Ayers explains the focus of his research, which seeks to reveal how underwater topography in the wetlands fringing the estuary affects interactions between predators and small fish. While restoration projects often focus on adding more water to this ecosystem and encouraging that water to overflow the river’s banks, Ayers says small fish need more than just water and wetlands to survive. Variation in habitat features, such as the width and depth of wetland channels that wind through these ecosystems, create a...
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22
Sep

Makeover for Delta Weed Patch & Salt Trap?

What began as a project to convert a submerged Delta island into habitat for endangered native fish has morphed into a multi-benefit package with additional payoffs for water quality and recreation. The collaborative design process for the Franks Tract Futures project brought initially skeptical local stakeholders on board and is being hailed as a model for future initiatives. Yet major uncertainties remain as interested parties explore the challenges of implementing a complex redesign of a big chunk of the Delta. The proposed project would take a big shallow lake full of weeds, deepen some parts, fill in others with new lands and fish habitats, add beaches and recreational amenities, and stanch the spread of salt water from the ocean toward...
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18
Jun

Sinking Islands Capture Carbon Credits

As sea levels rise and land in the Delta sinks, agencies and landowners are recognizing that levees alone will not protect critical fresh water supplies and infrastructure. Encouraged by a recently vetted new method for calculating carbon offsets from wetlands, a flurry of new climate adaptation projects on publicly owned islands strewn along the central Delta corridor aim to defend against sea-level rise, restore habitat, and reduce greenhouse gas emissions. Until recently, the prospect of selling carbon credits in the Delta remained fairly abstract.
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18
Jun

Highway 37: The Road to Restoration

From head-on collisions in the 1980s to crippling congestion now, Highway 37 is a familiar headache for highway engineers. Fearing that engineers might not take full account of the vast marsh restorations underway in the area, the Sonoma Land Trust, the Coastal Conservancy, and others joined in a State Route 37-Baylands Group. In 2017, the group laid down markers: Whatever is done with the east-west highway must also improve the passage of tides and stormwaters north and south, not further impede those flows.
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18
Jun

Squeezed by Geography

In most respects, Marin County is a privileged place. But its miles of Bay and ocean shoreline and many low-lying towns, positioned to afford easy coastal access and world-class scenery, represent a major liability in the era of sea-level rise. “Marin is the canary in the coal mine in some ways, because almost everything is in that narrow strip along the Bay,” says Roger Leventhal, a senior engineer with Marin County Public Works.
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18
Jun

Forty Miles of Creek, Six Adaptation Projects

In 2017, a perfect storm hit the City of San Jose in Santa Clara County. Coyote Creek, which winds through the heart of the city, overtopped its banks, flooding businesses and hundreds of homes up to depths of six feet. Thousands of people were evacuated and property damages exceeded $70 million. “If I’ve learned anything in my 25 years here, it’s that you have to give creeks room to move, which also creates more resilience to climate change,” says Valley Water's Afshin Rouhani...
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16
Apr

A new project should dramatically improve conditions for endangered steelhead trout in the lower reaches of Alameda Creek.

The project is part of a long-term effort to restore steelhead to Alameda Creek. Last year, for the first time in decades, the San Francisco Public Utilities Commission began releasing water from a newly retrofitted dam, effectively reviving an important tributary stream. Also in 2019, the Alameda County Flood Control District began construction of a key fish ladder at the BART line crossing that will allow adult steelhead to access the river’s headwaters. The new fish passage enhancement plan focuses on a section of the stream that flows through a highly urbanized area. Largely contained within channels of concrete and riprap, the water courses under a freeway overpass and several boulevard bridges. The water is warm, swift and shallow—an unfriendly...
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19
Mar

Taking a Break from the Corps

Corte Madera creek is an outsized problem for people in Ross and other towns built right up to its banks. “Our peaceful creek turns into a rushing torrent in winter,” says Chris Martin, who grew up in the small Marin County town. Finding a fix has been contentious since 1971, when the U.S. Army Corps of Engineers put a mile-long concrete flood control channel through Ross.
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19
Mar

Rebooting the Klamath

In 2002, more than 70,000 adult salmon died on the Klamath River when U.S. Bureau of Reclamation diversions caused water temperatures to spike. In February, the Klamath River Renewal Corporation, including the Yurok and Karuk Tribes, filed to take over management of four hydroelectric dams in the upper watershed. “There’s never been a project that has considered removing four dams at the same time on the same river...
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19
Mar

Dam Tweaks Yield Results

By Alastair Bland “After one year of flows, we’re seeing lots of rainbow trout,” says Brian Sak of the San Francisco Public Utilities Commission (SFPUC). For the first time ever, cold water is flowing steadily through Calaveras Dam in southern Alameda County, and into the creek canyon below. The return of rainbow trout to Calaveras Creek marks a milestone in an ongoing, multi-agency restoration of Alameda Creek, which drains more than 600 square miles of the East Bay. Since the dam’s construction in 1925 by the Spring Valley Water Company, no measurable flows have been allowed through the barrier. But facing legal action, the SFPUC agreed to overhaul its operations in the interests of steelhead recovery as part of its...
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19
Mar

Opening the Mouth of Walnut Creek

Paul Detjens is driving us from his Martinez office to a restoration site near the mouth of Walnut Creek on Suisun Bay, a project he spearheads as an engineer for the Contra Costa County Flood Control District. These lower reaches of the creek — straightened, widened, and leveed by the U.S. Army Corps of Engineers — have been a sluggish, silt-filled problem for more than half a century. Detjens has worked to find a solution for the last 17 years. Now that the district has taken the unusual approach of parting ways with the Corps in favor of local control, a fix is finally in sight. Goals include protecting people from floods, restoring habitat, reconnecting the creek with its historical...
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05
Mar

After nearly 30 years in refuge management on public lands, Anne Morkill is leaving government, but not wildlife, behind.

Following her February 2020 retirement from managing the San Francisco Bay National Wildlife Refuge Complex, which she led for nearly a decade, Morkill is taking the helm at the Laguna de Santa Rosa Foundation, a nonprofit that stewards one of the largest freshwater wetlands complexes on the northern California coast. Morkill believes that San Francisco Bay provides unusual potential for restoring habitat for wildlife in a highly urban environment. “That’s what makes it so special,” she says, citing the Bay Area’s history of environmental activism, the broad coalition of groups that support wetland restoration for both its ecological and economic benefits, and a citizenry that recognizes the value of a healthy ecosystem and is willing to provide funding to achieve...
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22
Jan

A new system for treating agricultural drainage water in the Delta could also help rebuild subsided islands.

The approach—known as a Chemically Enhanced Treatment Wetland—combines chemical treatment with natural wetland processes; researchers tested it on Twitchell Island, which features corn and rice crops, as well as wetlands. They dosed agricultural ditch water with dissolved organic material (DOM), then treated it with a coagulant to precipitate the DOM, forming flocculant. The resulting water then passed though treatment wetlands, where the flocculant settled and blended with plant detritus in the sediment. The study, reported in the September 2019 San Francisco Estuary and Watershed Science, found that the combined system removed drinking water contaminants including dissolved organic carbon, disinfection byproduct precursors, and methylmercury. Another possible benefit is subsidence reversal: the researchers found that sediment and carbon accreted about four times...
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