Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program
Todd works on flow and sediment issues on the Trinity River for the TRRP and is currently investigating flow effects on temperature stratification in river pools, development of an acoustic technique for bedload monitoring, and evolution of Rush and Indian creek deltas and their capacity for rearing juvenile Chinook salmon. Todd completed a four-year enlistment in the U.S. Coast Guard before starting his career in river and salmon restoration in 1994.
His work has mainly focused on the relationship between sediment transport dynamics, streamflow, and biological populations in rivers in the Western U.S., Alaska, New York, and Costa Rica. Todd has earned a B.S. in Watershed analyses and restoration and an M.S. in Watershed Management from Humboldt State University and a Ph.D. in Water Resources from the University of Idaho. His academic research included developing and testing an equation that predicts entrainment of waterlogged wood in rivers, streambed packing effects on sediment mobility, relative stability of salmon redds and ambient streambed areas, and salmon spawning effects on hyporheic (groundwater) flow and marine nutrients from salmon in streams.
2024 Science Symposium Presentation
Thermal stratification in pools on the Trinity River.
Day 2 of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program presents , “Thermal stratification in pools on the Trinity River.”
The start of summer in Trinity County has been a hot one, with 100° plus degrees for 10 days straight in early July combined with another series of 100° degree days forecasted for the latter half of the month. As warm-bodied land dwellers, we cope with heat by seeking refuge: interior shelter, air conditioning, shade, and of course, water. Refreshing water comes in many forms – pools, sprinklers and creeks, lakes, and rivers – whatever is available to us! Cold-blooded salmon are not so different in this regard. Throughout their various life stages, they too seek water temperatures that provide opportunities for success.
The construction and operation of Trinity and Lewiston dams have altered the Trinity River in many ways. Program scientists continue to learn about the complex ways dams affect water temperatures and fish within this altered system. For many years, “the colder the water the better” has been the dogma of salmonid management. While cold water can be beneficial, scientists have long known water that is too cold can also be detrimental. Like nearly all animals, salmonids grow and survive best within an optimal range of water temperatures, and temperatures above and below this range negatively affect them. Temperature variability is highly important because it allows fish to find temperatures that are optimal at different times of day for the various activities they undertake to grow and survive.
Last August, in the River Riffle newsletter we published “A Brief Introduction to Thermal Ecology of the Trinity River”. The article describes the thermal ecology of local rivers which experience cold, wet winters and hot, arid summers, characteristics of the Mediterranean climate of our region. Salmonids thrive where thermal diversity is available because they can maximize growth and survival by seeking optimal temperatures. For example, a juvenile salmonid’s job is to eat, grow and survive. At this stage, juveniles move from higher velocity areas where they feed in relatively cold water before residing in slower warmer areas of pools to rest and digest. The warm, slow water helps them relax and digest. Moving to take advantage of temperature differences allows them to efficiently digest their food to gain weight and grow larger. Eat, rest, digest, and repeat. The more that young fish can take advantage of these diverse temperature and flow conditions the better they can digest food into growth, which in turn improves their chance of survival in the ocean.
The seasonal, daily, and spatial temperature environment in the Trinity River before dams were constructed differed considerably from what we see today. Year to year variability was driven by winter precipitation and snow accumulation. As temperatures rose in the spring, snowmelt provided a regenerative increase in flow and expansion of habitat. On the journey from melting snow through creeks and tributaries to the mainstem river, water was warmed by the longer, warmer days, often reaching optimal temperatures for growth. As the snowmelt receded and the river returned to summer low flow, water temperatures in large, deep pools would stratify into different layers. In both these ways, temperature variability was provided to not only juvenile salmonids but also native frogs, turtles, and aquatic insects. The diversity of temperatures within nooks and crannies, combined with different depths and sheltered areas of the river formed a robust underwater nursery for the aquatic wildlife below. The timing and magnitude of these transitions and the variability of temperature depended on rain and snow patterns months before, yet the pattern was predictable. Fish and wildlife evolved over millennia to take advantage of this cycle.
The presence and operation of Trinity and Lewiston dams have dramatically altered the temperature regime in the Trinity River. As the spring and summer days heat up, Trinity Reservoir water stratifies to form a large pool of cold water below a depth of about 6 feet. Above this depth, water temperatures are warmed by the sun. Although infrastructure on some dams allow water to be drawn selectively from throughout the water column, Trinity Dam can only draw from its deep cold-water pool. Cold water that is released from Trinity Dam to Lewiston Reservoir warms as it flows towards Lewiston Dam, but releases to the river are still much colder throughout the summer than what the river experienced at Lewiston before the dams were in place. While the pre-dam river and other undammed local rivers warm in the spring to provide ideal temperatures for fish growth, the cold-water releases from Lewiston Dam keep the mainstem Trinity River so cold that growth of native salmonids, frogs, and turtles is stunted.
While juvenile fish population data collected by the Hoopa and Yurok Tribes and the U.S. Fish and Wildlife Service show that significantly more juvenile salmonids have been produced by the Trinity River since ROD releases began in the early 2000’s, these data also show that juvenile fish size has notably decreased (Pinnix etal 2022. Figure 4, Figure 12). Program scientists strongly suspect that large cold-water releases in spring are a significant contributing factor to this decrease in fish size, and smaller fish have a lower chance of surviving in the ocean. Despite increases in the number of juvenile salmonids leaving the Trinity River, adult returns have not increased, and in fact have declined since 2000.
Scientists hypothesize that moving some of the Trinity River flow releases from springtime to the winter months would provide better growth conditions for juvenile salmonids by enabling summer flows to reach baseflow earlier in the year, allowing for the river to once again benefit the outmigrating fish (Asarian etal 2023, Abel etal 2021, Naman etal 2020). But what about the adult salmon. Would a warmer river harm them?
Adult salmon, like Chinook and coho, return to freshwater from the ocean with a different strategy than juveniles. Their focus is instead on the need to conserve energy for spring and summer migration in spring and spawning in fall. The prized spring-run Chinook take advantage of snow melt runoff in the spring to swim upriver. Along the way they commonly rest by day in slow water at the bottom of large, deep pools, behind fallen trees, under bedrock outcroppings, and downstream of large boulders. Water temperatures in the river increase as days get longer and hotter, while they can vary throughout the day as water cools at night and warms in daytime.
As spring progresses into summer, migration can become limited to cooler times of day, as the adults rest in the cold bottoms of thermally stratified pools by day and resume their upstream migration when the entire river has cooled at night. Finally, when adult spring-run Chinook reach their over-summer holding habitat, they can spend weeks to several months in deep pools with slow water to conserve energy for spawning in the fall.
There are many objectives of the regulated flow releases to the Trinity River from Lewiston Dam. Summer baseflow releases aim to provide favorable temperatures for migrating and holding spring Chinook who have lost access to habitat in the upper watershed above Trinity and Lewiston dams. This temperature mitigation is achieved by flow releases of 450 cubic feet per second from the end of the spring release until mid-October. A recent research paper published in the Hydrological Processes journal, The mechanics of diurnal thermal stratification in river pools: Implications for water management and species conservation (Buxton et al. 2022) explores the effects of summer flow management on the Trinity River. The research examines pre-dam flow records from 1911-1960 when summer flows averaged 177 cubic feet per second in the Trinity River in comparison to flows since 2000 that measure 2.5 times higher at 450 cfs. The increased flow and cold deep water drawn from Trinity Reservoir create summer temperatures that are around 18°F cooler (10°C) than pre-dam temperatures in summer at Lewiston. The post-dam Trinity River experiences more water and higher velocity, yet its habitat areas are remarkably smaller than the pre-dam environment which received less water and lower velocity.
Above, we mentioned pool stratification in Trinity Reservoir. The stratification occurs because the slow-moving water warms and becomes less dense, which causes it to buoy toward the surface. This stratification of temperatures occurs in river pools that are large and deep enough (typically greater than 9 feet in depth). Size is important because when flow through the pool slows to a very low speed it prevents the warm top water from mixing with the cold bottom water and allows for stratification. This thermal layering in stratified pools is important for salmonids because it provides both adult and juveniles the opportunity to place themselves in the right temperature at the right time of day to best improve their survival and/or growth.
A key component of the pool stratification research was the measurement and modeling of temperatures as well as flow velocities in correctly sized pools for holding spring Chinook both below and above the dams. Data were collected and compared from a control pool in the Trinity River upstream of Trinity Reservoir as well as below Lewiston Dam (Pear Tree Pool). The findings showed that the pool above the dams exhibited stratification, providing the range of beneficial temperatures that follow the annual pattern of sun exposure and summer flows that naturally occur in our region.
In contrast, stratification did not occur in the pool below the dam at Pear Tree. Flows were too fast, mixing all water into one layer of uniform temperature. While temperatures in the Pear Tree pool were suitable for holding adult spring Chinook, the higher velocities increased their energy expenditure, likely taxing their energy supply needed for building and protecting redds and ultimately laying and fertilizing eggs. Unfortunately, the pool also lacked temperature diversity for juvenile salmon. Juveniles were presented with uniform temperatures and higher velocities, also taxing their energy supply needed for digesting their food to put on weight. Not to mention losing the benefits of temperature diversity discussed above.
Temperature diversity combined with variable water depths and velocities, refuge from predators, and plentiful food are important factors determining a young fish’s ability to grow and survive. While we often think “cold water is best,” perhaps a more accurate statement would be “diverse water temperatures are essential”! While that may seem obvious, a little clarification can improve our understanding of the needs of fish and how we may better serve them. Rivers in our region support a multitude of aquatic and land-based animals, insects, birds, and amphibians. Providing habitat diversity – including variable water temperatures – are paramount to meeting the needs of our wildlife community, and Program scientists continue to learn about the complex interactions between temperature and ecosystem health, hoping to better inform management on the Trinity River.
If you are interested in learning more about pool stratification on the Trinity River, join the lead author on this study, Dr. Todd Buxton, for Science on the River: Stratification of water temperatures in pools on the Trinity River at the Lewiston Hotel and Dance Hall on August 28, 2024 – 6pm. Todd is a Hydrologist and Fish Biologist with the Bureau of Reclamation – Trinity River Restoration Program who will lead us through the recent Trinity River study on thermal stratification in river pools. Pool stratification is an important ecological function of natural river systems and Todd’s findings show that pools in the Trinity River below Lewiston Dam are unable to stratify and provide critical habitat for juvenile and adult salmonids. Todd will discuss why the habitat is important for both life stages of salmon as well as other interesting findings from the study.
Pinnix, W.D., S.P. Boyle, T. Wallin, T. Daley, and N.A. Som. 2022. Long-Term Analyses of Estimates of Abundance of Juvenile Chinook Salmon on The Trinity River, 1989-2018. U.S. Fish and Wildlife Service. Arcata Fish and Wildlife Office, Arcata Fisheries Technical Report Number TS 2022-40, Arcata, California. [link to download]
Asarian, J. E., K. De Juilio, S. Naman, D. Gaeuman, and T. Buxton. 2023. Synthesizing 87 years of scientific inquiry into Trinity River water temperatures. Report for the Trinity River [Link to download].
Naman, S., K. De Juilio, and K. Osborne. 2020. Juvenile salmonid temperature target recommendations. Memorandum to Ken Lindke, Fish Work Group Coordinator. Trinity River Restoration Program, Weaverville, California. [Link to download].
Abel, C., K. de Juilio, K. Lindke, S. Naman, and J. Alvarez. 2021. Shifting a portion of Trinity River spring releases from Lewiston Dam to the winter period: a flow management action to benefit juvenile salmonid habitat availability, growth, and outmigrant timing. White-paper for the Trinity River Restoration Program (TRRP). TRRP, Weaverville, California. [Link to download].
While there are dozens of milkweed species and subspecies in North America, within the Trinity River Watershed there are four documented species, including showy milkweed (Asclepias speciosa) narrowleaf milkweed (Asclepias fascicularis), heart leaf milkweed (Asclepias cordifolia) (DeCamp, 2021, p. 294, 362) and the rare lesser seen serpentine milkweed (Asclepias solanoana) (Kauffman, 2022, p. 155). Each type has unique leaf sets and structure topped with wonderful showy flowers and dramatically large seed pods that propagate via wind in the fall. The flowers are a haven for area pollinators and the plant itself plays a critical role in the majestic monarch butterfly migration. In our region, monarch butterflies, generally choose one type of milkweed, showy milkweed (A. speciosa), to lay their eggs and because of this, the availability and frequency of the plant along the monarch’s migratory path are critical to it’s survival (Western Monarch Milkweed Mapper, 2024).
Photo: Heart leaf milkweed (A. cordifolia) has matured it’s showy seed pods in the Trinity Alps. [Kiana Abel, TRRP]
A monarch’s annual lifecycle goes through upwards of 4 generations during migration. Migration north (and east for western monarchs) happens typically between March and August each year. During migration, an adult female will lay eggs on the underside of young healthy milkweed leaves, hatch, eat, crystallize and repeat. As summer progresses, roughly in the third or fourth generation the western monarch will eventually turn south and west to return to their overwintering sites on the California coast (and in some cases Mexico).
All species of milkweeds are characteristic of the milky sap in their stems and leaves which contain a lethal brew of cardenolides (heart poison). If grazed, animals and insects are served a warning with distasteful, hairy leaves. If ingested, a grazer is confronted with vomiting and potentially death in higher doses. The negative effect on agricultural livestock like sheep and cows led farmers and agriculturalists toward eradication efforts. Over time, the combination of increased land use and herbicide led to a significant decline in available milkweed, with monarch populations following suit.
The handful of insects that do eat the plant are all incredibly colorful which in-turn serves as a warning to their predator’s (Monarch Joint Venture, 2024). If a monarch caterpillar were to be eaten it’s predator will encounter a nasty taste and hopefully drop it’s prey. For the majority of insects like bees, moths and other butterflies the main attraction to milkweed is the flower which provides nectar during a time in the summer when most other flowers have spent. For each type of milkweed found, the flowers are showy, intricate and are certainly worth a close-up look.
Milkweed has proved useful to people as well. Ethnobotanists have documented historic and current use of the plant in fiber, food and medicine in the United States and Canada. Milkweeds supply tough fibers for making cords, ropes as well as for course cloth. Native Californian tribes use the plant for all the purposes listed above. In one documented case of a Sierra Miwok woven deer net, the trap measured 40 feet in length and contains some 7,000 feet of cordage, which would have required the harvest of 35,000 plant stalks. Among Californian Native tribes, the most common documentation of use was to obtain a kind of chewing gum from the sap of showy milkweed (A. speciosa). The sticky white sap is heated slightly until it becomes solid, then added to salmon or deer gristle (Stevens, M., 2006).
The decline of wild milkweed plants as well as the majestic monarch butterfly has spawned a cultivation movement to encourage everyday gardeners to plant. If you reader, would like to cultivate milkweed in your pollinator garden, make sure to plant it in a location where it can expand. In suitable conditions, milkweed can outcompete other plants and on occasion infrastructure such as plant boxes or walkways. A second consideration is where the location of where you’d like to plant in accordance with the migratory path of the monarch. If you are in a costal overwintering area, it is more beneficial to monarchs to plant nectar plants versus nursery plants. A planting of A. speciosa may falsely signal that they are in a location fit for reproduction leading to a disruption in their migration cycle.
When you’ve picked the best species for your area you can propagate milkweed from seed or rhizome. Collect seeds from pods once they have ripened, but prior to splitting open. Experienced cultivators planting in high elevation or colder climates have documented higher success rates with seed by using a cold treatment for three months and then planting directly into the ground the first fall after collection (Stevens, M., 2006). Propagation by rhizome is also easy and reliable. Create cuttings when the plant is dormant and make sure the rhizome has at least one forming root bud. Success is also dependent on on timing. Harvest or divide plants at the beginning of the rainy season and plant them in the ground by late fall so they can develop enough root growth to survive the winter. Irrigation in the first year will improve survival, and by the second year the root system should be well enough established so plants will survive on their own (Stevens, M., 2006).
Asclepias sp. Milkweed Native American Ethnobotany Data Base. A Database of Foods, Drugs, Dyes and Fibers of Native American Peoples, Derived from Plants.
The Woolly Sunflower is a common attraction along the Trinity River corridor and watershed. In our area, viewers can see it in a few different varieties split between high and low country. The low country version is found in large colonies exposed to dry and hot conditions. Viewers commonly see it along roadsides defying logic by clinging to rocky cliffs showing off their sweet yellow pedals and silvery leaves and stems.
Photo of a patch of Common Woolly Sunflower taken near Burnt Ranch, generously provided by Veronica Yates.
Eriophyllum lanatum is a perennial herb native to western North America. It has long, thin stems with small pinnately lobed, green leaves and small, yellow flowers. When you get up close and personal you notice a few unique characteristics. Prior to the bloom, the tips of the flower buds turn a sweet reddish purple and the silvery color of the stem and underside of the leaves is actually a layer of tiny hairs. These hairs serve a specific purpose for the plant and act to conserve water by reflecting heat and reducing air movement across the leaves surface [1]
Photo: taken at the Oregon Gulch Restoration Site. E. lanatum was a part of the seed mix dispersed post restoration as part of the revegetation efforts by Hoopa Valley Tribal Fisheries. Photo generously provided by Veronica Yates.
This perennial plant’s bloom is prolific and prolonged typically beginning in March and lasting sometimes into August making it of special value to native bees, butterflies, and other important pollinators who are attracted by the bright yellow sunflower-like pedals. Due to this wildflower’s showy nature as well as its excellent tolerance to drought, it makes for a terrific addition to cultivated butterfly gardens. It can be propagated by seed, cuttings or by inquiring to purchase from your local nursery [2].
The woolly sunflower has been recorded to be used by the people of the Miwok tribe (California) to sooth aching parts of the body by making a poultice of the leaves; the Skagit (Washington) rub the leaves on skin to prevent chapping; and the Chehalis (Washington) use the dried flowers as a love charm [3].
The June Quarterly meeting of the Trinity Management Council was held in Weitchpec, Ca. located near the confluence of the Trinity River and the Klamath River. The meeting was hosted by the Yurok Tribe and took place Wednesday, June 5 and Thursday, June 6. During the first day members received presentations from the acting Trinity River Restoration Program Executive Director, James Lee regarding program updates. Topics in the Executive Directors Report covered major activities since the March TMC meeting as well as organizational updates, budget updates, Implementation Branch updates, Public Outreach updates and Science Branch updates. The ED Report can be downloaded by clicking here.
Additionally the council received updates from various membership staff regarding Central Valley Project operations (Elizabeth Hadley, Reclamation), Trinity River Division Reconsultation (Kristen Hiatt, Reclamation), Fish workgroup synthesis report recommendations (Kyle De Juilio, Yurok Tribe) and TRRP channel rehabilitation site status and schedule (Oliver Rogers, TRRP). There were two informational presentations given to the council, the first a presentation from Whiskeytown National Park Service staff regarding the policy around keeping Whiskeytown Reservoir full as well as a presentation on the Remote Site Incubator (RSI) program (download the presentation) implemented by the Yurok Tribe on Grass Valley Creek in spring of 2024 by Zac Reinstein.
On day 2 In addition to a presentation from Hoopa Valley Fisheries Department Director, Mike Orcutt on chinook management post-Klamath dam removal in the second day of meetings the council received 3 presentations focused on program updates and 2 presentations regarding updates to TMC procedure. The first presentation was given by the TRRP Science Coordinator, Eric Peterson who updated the council regarding fiscal year 2025 science proposal recommendations. Second, James Lee, acting Executive Director presented the proposed budget for fiscal year 2025 for council approval. The council voted unanimously to adopt the FY25 budget proposal with one amendment. The amendment reads as the following, “Mike Orcutt made a motion to follow the IDT’s recommendation to fund the additional three proposed projects up to $610,000 subject to IDT team review and contingent on their concurrence. The projects proposed include the Restoration Vegetation Diversity (TRRP-2025-1), Benthic Macroinvertebrates (TRRP-2025-2) and Initial Steps to Foodscape Model (TRRP-2025-3).”
In the afternoon, the TMC discussed amending the bylaws to more clearly define procedure in calling for executive session during management meetings. The TMC voted unanimously to amend this section to read as the following, “All regularly scheduled and special meetings of the TMC shall be open to the public except executive sessions. Executive sessions shall be comprised of one representative per TMC entity and invitees. Executive sessions shall be limited to issues related to contracts, personnel, legal matters, or other sensitive matters as determined by the TMC. The request for a specific executive session (including invitees) will be clearly proposed via a motion and voted to proceed by the TMC in accordance with Sections 603, 604, and 605.“TMC bylaws (Section 600, Bullet D)
The final topic of the quarterly meeting was a discussion titled, Winter Flow Variability Planning and was brought by TMC member Radley Ott, who serves in the seat for California Natural Resources Agency. The discussion centered around the desire from technical groups and the public, who have expressed the need for advanced planning regarding water management. These groups were looking to the TMC for guidance on how Water Year ’25 would be managed with the knowledge that the management council was not able to pass a flow recommendation to the Department of the Interior in Water Year ’24. The council decided on creating a timeline for proposals that would include both limitations as well as implementation. The motion, that passed with 1 vote against and 7 votes in favor, reads as follows, “Any recommendations or conditions for WY 2025 flows between 01 Oct and 15 April are to be submitted to the Flow Workgroup by 19 July and any specific hydrographs are to be submitted to the Flow Workgroup by 9 August.”
Sarah Yarnell, Ph.D., Associate Professional Researcher at the Center for Watershed Sciences, University of California – Davis
Sarah is an Associate Professional Researcher at the Center for Watershed Sciences. Her studies focus on integrating the traditional fields of hydrology, ecology and geomorphology in the river environment. She is currently conducting research that applies understanding of river ecosystem processes to managed systems in the Sierra Nevada, with a focus on the development and maintenance of riverine habitat. She is a recognized expert in the ecology of the Foothill yellow-legged frog (Rana boylii), a California species of special concern that is listed as threatened in some regions, and she was the first researcher to apply sediment transport and two-dimensional hydrodynamic modeling techniques to the evaluation of instream amphibian habitat.
Her experience includes consultation as a technical expert for various hydroelectric power relicensing projects, where she has worked closely with government resource agencies and the private sector to assess the impacts of environmental flows on aquatic biota and provide recommendations for developing flows that improve the functioning of river ecosystems. She is currently working with colleagues to apply a Functional Flows approach to the development of environmental flow criteria throughout the state. In recent years, her research experience has expanded to include evaluation and restoration of headwater systems, particularly montane meadows in the Sierra Nevada and Cascade ranges. Throughout her time at CWS, she has co-taught field-based river courses, such as Ecogeomorphology, and she teaches as a part-time lecturer for the Department of Earth & Planetary Sciences. She is a member of the Hydrologic Sciences Graduate Group and finds working with students to be one of the highlights of her job.
2024 Science Symposium Presentation
Adaptively Managing a Functional Flow regime in California.
Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Sarah Yarnell, Ph.D., Associate Professional Researcher at the Center for Watershed Sciences, University of California – Davis gives her presentation titled, “Adaptively Managing a Functional Flow regime in California.“
Daniele Tonina joined the Center of Ecohydraulics Research and the Department of Civil & Environmental Engineering in 2009. Natural environments are complex systems that require a holistic approach for synthesizing physical and biological processes. He follows this approach in his research, which can be broadly defined as ecohydrology. His research interests are in identifying and modeling linkages between physical processes and biological systems. This line of research improves our knowledge and ability to manage and protect river basins, water supplies, and riverine ecosystems, and thus forms an important basis for new public policy, urban development, and engineering designs. His research is not focused on one subject, but it examines the connection and interaction of different components that form a natural system.
His interests include surface and ground water processes and the interface between these two major systems — the hyporheic zone. In subsurface hydrology, he has investigated solute transport in heterogeneous formations with a stochastic approach. In surface waters, he is interested in sediment transport, river morphology response to disturbances and their effect on solute mixing and the aquatic habitat. He is particularly interested in surface-subsurface water interaction and its implications for ecosystems and water quality. He has been investigating how these interactions affect nutrient cycles, in-stream self-cleaning processes, both of which address engineering needs and answer ecological questions on how to manage and protect water resources. He is interested in defining the importance of hyporheic flow in different environments and under changing conditions. He is currently collaborating on the evaluation of a new airborne green lidar technology for surveying both terrestrial and aquatic systems (EAARL systems). This tool will provide extremely accurate topographic data of river networks and their surrounding riparian and floodplain zones and will support new research in river network evolution and structure, aquatic and terrestrial habitats, and surface processes.
2024 Science Symposium Presentation
Nitrification/denitrification, temperature and dissolved Oxygen changes within the hyporheic zone and emissions of greenhouse gases.
Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Daniele Tonina, Ph.D., P.E., gives his presentation titled, Nitrification/denitrification, temperature and dissolved Oxygen changes within the hyporheic zone and emissions of greenhouse gases.
John Buffington, Ph.D., Research Geomorphologist, U.S. Forest Service
John Buffington is a Research Geomorphologist with the U.S. Forest Service, Rocky Mountain Research Station in Boise, Idaho. He graduated from the University of California Berkeley in 1988 with a B.A. in geology and from the University of Washington in 1995 and 1998 with M.S. and Ph.D. degrees in geomorphology.
He was a National Research Council Scholar from 1998-2000, a professor in the Center for Ecohydraulics Research at the University of Idaho from 2000-2004, editor of the Journal of Geophysical Research: Earth Surface from 2015-2018 and has been an editorial board member of Hydrological Processes since 2015. His research focuses on fluvial and hillslope geomorphology of mountain basins, biophysical interactions, and the effects of natural and anthropogenic disturbances on aquatic habitat. He has been a member of the Program’s Science Advisory Board since 2010.
2024 Science Symposium Presentation
Stability of channel morphology and aquatic habitat in a changing climate: Implications for management of regulated rivers.
Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as John Buffington, Ph.D., Research Geomorphologist, U.S. Forest Service gives his presentation titled, “Stability of channel morphology and aquatic habitat in a changing climate: Implications for management of regulated rivers.”
Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program
Todd works on flow and sediment issues on the Trinity River for the TRRP and is currently investigating flow effects on temperature stratification in river pools, development of an acoustic technique for bedload monitoring, and evolution of Rush and Indian creek deltas and their capacity for rearing juvenile Chinook salmon. Todd completed a four-year enlistment in the U.S. Coast Guard before starting his career in river and salmon restoration in 1994. His work has mainly focused on interties between sediment transport dynamics, streamflow, and biological populations in rivers in the Western U.S., Alaska, New York, and Costa Rica.
Todd has earned a B.S. in Watershed analyses and restoration and an M.S. in Watershed Management from Humboldt State University and a Ph.D. in Water Resources from the University of Idaho. His academic research included developing and testing an equation that predicts entrainment of waterlogged wood in rivers, streambed packing effects on sediment mobility, relative stability of salmon redds and ambient streambed areas, and salmon spawning effects on hyporheic (groundwater) flow and marine nutrients from salmon in streams. Todd’s free time is preferably spent building wood structures of any kind and caring for the land where he lives along Browns Creek.
2024 Science Symposium Presentation
History of fine sediment and its impacts on physical processes and biologic populations in the Trinity River.
Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program gives his presentation titled, “History of fine sediment and its impacts on physical processes and biologic populations in the Trinity River”.
David Gaeuman, Ph.D., Senior Geomorphologist, Yurok Tribe, Design and Technical Services Program
David Gaeuman joined the Yurok Tribe Fisheries Department in 2019 after 13 years as a U.S. Bureau of Reclamation employee in the Weaverville TRRP office. Prior to arriving in Weaverville in 2006, he spent 3 years conducting sediment transport research in the Missouri River with the U.S. Geological Survey and worked in stream monitoring and restoration throughout the mountain west while earning a master’s degree in stream geomorphology at the University of Montana and a Ph.D. from Utah State University.
2024 Science Symposium Presentation
A decade of tracking coarse sediment augmentations: where has all the gravel gone?
Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as David Gaeuman, Ph.D., Senior Geomorphologist, Yurok Tribe, Design and Technical Services Program presents, “A decade of tracking coarse sediment augmentations: where has all the gravel gone?”