Category: News


The government of Cambodia announced on 16 March that it would postpone development of any of new dams on the mainstem Mekong River for 10 years, citing the need to develop alternative sources of energy for the country’s future development. While Cambodia has built a large dam on the SeSan-SrePok (important downstream tributaries), and left open the possibility it might build other tributary dams, the mainstem dams long-planned for Sambor and Stung Trang are on hold for the next decade. See story in the Guardian here.

Restoring Process in Rivers: Results from the 15th Annual Berkeley River Restoration Symposium at UC Berkeley

While the US was arguably more active in river restoration in the 1980s, most of the projects now undertaken in the US are still form-based attempts to create idealized features.  In many cases, these artificial constructions are not sustained by current, altered river processes.  In the EU, by contrast, many projects explicitly aim to restore process, even when this means allowing a ‘messy’ river to develop.

How can we restore true geomorphic and ecological processes in rivers?  This question was addressed in the 15th Annual Berkeley River Restoration Symposium (7 December 2019), in keynote talks by Hervé Piégay of CNRS (the French national research agency) and University of Lyon, and Damion Ciotti of the US Fish and Wildlife Service.  Piégay’s talk, Revitalizing rivers: learning from a few European case studies, summarized some of the key lessons learned from recent restoration efforts in the EU.  Despite more projects in the US now claiming to be ‘process based’, real restoration of process is rare. How can we distinguish true process-based restoration projects?  Damion Ciotti’s talk, ‘Process-based design criteria for ecological restoration’ presented four distinct attributes of true process-based restoration, along with a detailed illustration of the application of these criteria to a restoration project in the foothills of the Sierra Nevada.

In addition to these keynote talks, graduate students in the River Restoration course presented their independent research projects, including a comparison of a conventional salmon spawning habitat restoration project heavily dependent on external energy sources (diesel fuel) with the energy exerted on the ‘restored’ reach by a natural flood; an evaluation of a side-channel restoration for salmon on Lagunitas Creek; the Vermont and Washington State programs to set aside river corridors; and post-project appraisals of river restoration projects on the Truckee River, Reno, and Cerrito and Baxter Creeks in the San Francisco Bay region.  Panels of experienced practitioners and researchers provided perspective on themes arising in the presentations.  Click here to see the papers summarizing the graduate student research projects.

The symposium is presented annually by the UC Berkeley Department of Landscape Architecture & Environmental Planning, and the Institute of International Studies Interdisciplinary Faculty Seminar Water Management: Past and Future Adaptation.

Keynote Speaker Bios

Hervé Piégay is research director at the National Center of Scientific Research, at the laboratory Environnement, Ville, Societe, based at the Ecole Normale Supérieure of Lyon (France). His Ph.D. (1995) documented interactions between riparian vegetation and channel geomorphology. His research is focused on river management, planning and restoration, contemporary history of rivers and their catchments, analyzing human controls on environmental change, floodplain and former channel sedimentation, sediment transport, and budgeting.  His work involves integrated sciences, with a strong emphasis on methodological frameworks and innovative tools using tracking techniques, GIS and remote sensing. He frequently works with practitioners to provide insights for river management, planning, and restoration.

Damion Ciotti is a Restoration Biologist with the US Fish and Wildlife Service in Auburn California. He has over 10 years of experience in design and implementation of stream, river, and wetland restoration in the Sierra, Cascades, Great Basin and Appalachia. Major projects include restoration of stream delta systems in the upper Klamath Basin and stream and floodplain reconnections in the Sierra and Cascades. He is interested in testing applications of ecological science and theory to restoration practice. He also coordinates the Tribal Grants Program for the US Fish and Wildlife Service. Damion has an MS in Environmental Science from Oregon State University and a BS in Soil Science from Penn State and was a Peace Corps volunteer in Paraguay.

About the Class

Restoration of Rivers and Streams (Landscape Architecture and Environmental Planning 227) is taught by Professor Matt Kondolf.  Offered annually since 1992, it is the longest-running course devoted to river restoration at a major research university. This graduate-level course emphasizes understanding of underlying goals and assumptions of restoration, and integration of science into restoration planning and design. Students review restoration plans and evaluate completed projects. In addition to lectures and discussions by the instructor, students, and an extraordinary set of guest lecturers drawn from the active restoration community, the principal course requirement is an independent term project involving original research and a presentation at this Symposium.



Restoring river habitats below dams through gravel augmentation and bank erosion

Building on recent research on the Rhine River between France and Germany, a research team based in Strasbourg has published a review of scientific literature on projects to restore channel complexity downstream of dams.  While dam removal has attracted enormous attention in recent years, with notable successes on the Elwha River, the reality is that most dams are here to stay and most river reaches in the developed world are downstream of dams.  As these dams capture sediment, they create conditions of sediment deficit in many river reaches downstream. This review found relatively few studies documenting projects to restore sediment supply via gravel augmentation and fewer still via restoration of channel erosion processes below dams (mostly examples from northern Europe).  Biological monitoring shows benefits from these projects, whose increasing popularity reflects growing interest in restoration of fluvial process, and an evolving perspective towards adaptive or coupling management approaches to promote the recovery of natural processes in rivers below many dams and thus to improve ecological response.  


The paper, Restoring fluvial forms and processes by gravel augmentation or bank erosion below dams: A systematic review of ecological responses, by Cybil Staentzel et al. is available for free download here until 01 February 2020.

Reservoir sedimentation and what to do about it.

In June 2019, Reservoir Sediment Management: Building a Legacy of Sustainable Water Storage Reservoirs was released by the National Reservoir Sedimentation and Sustainability Team (NRSST), a consortium of engineers and scientists from federal agencies, consulting firms and universities, including UC-Berkeley’s RiverLab, studying the impacts of sediment on the nation’s water supply.


This paper outlines the origins and legacy of reservoir sedimentation, where sediment being transported by a river begins collecting behind a dam. While sediment transport is of great benefit to riverine ecologies, the trapping of sediment means decreased water storage capacity in dams, greater flood risk, and reduction in hydropower functions.

Additionally, the paper proposes the following management strategies for mitigating further sedimentation and dealing with existing sediment:

  • Reduce sediment yield entering the reservoir by trapping more upstream;
  • Move sediments away or through reservoirs;
  • Flush or dredge existing sediment deposits;
  • Adapt to and plan for reduced storage volume in the future. (Randle, 2019)


Read the full paper by clicking here


Tim Randle of the NRSST and Manager of the Sedimentation and River Hydraulics Group at the Bureau of Reclamation was featured in H2O Radio’s recent story “Damned from the Start” discussing the reservoir sedimentation as it applies to the flooding of the Niobara River behind the Gavins Point Dam in Nebraska.


Listen to the full story here

ReNUWIt Research Spotlight

For the past year, RiverLab’s Anneliese Sytsma has been working with Engineering Research Center ReNUWIt – Re-inventing the Nation’s Urban Water Infrastructure – on her PhD dissertation research. This month, ReNUWIt highlighted her research on ‘connected impervious surfaces’ on the ReNUWIt website- see here. Anneliese is working on the manuscript now and hopes to publish before the end of the year.

Connected or unconnected? A new method for estimating connectivity of impervious surfaces across variable soils, slopes, and rainfall scenarios

Accurate methods to predict impervious surface connectivity are needed to improve hydrologic modeling and efficient siting of distributed stormwater technologies. ReNUWIt researchers are developing a new method for estimating impervious surface connectivity across different soil types, slopes, rainfall scenarios and landcover parameters. The outcomes of this research may be used as hydrologic model inputs and to inform more efficient distributed stormwater control siting across heterogeneous urban landscapes.

AGU Session: Managing multifunctional watersheds for the 21st century

Join us at American Geophysical Union (AGU) fall meeting in the session “Managing multifunctional watersheds for the 21st century‘ (Session # GC052). Organized by Rafael Schmidt (RiverLab alum), P. James Dennedy-Frank, and Dr. Kondolf, this session will tackle the increasing demand for watershed services and capacity of green-grey solutions to meet this demand. We invite submissions to this session that showcase both exemplary case studies and systematic cross-site analyses addressing key questions for an integrated and strategic  management of multifunctional watersheds:  (1) at what scales and contexts do green solutions provide tangible benefits to society; (2) and how can  combined  grey and green infrastructure portfolios be designed to maximize benefits for both nature and people?

The deadline for abstract submission is 31 July 2019 23:59 EDT/03:59 +1 GMT.

2019 AGU Fall Meeting

The American Geophysical Union (AGU) annual fall meeting will be held 9 – 13 December 2019 in Moscone Center, San Francisco. The Fall Meeting is the largest international Earth and space science meeting in the world, with speakers from around the globe presenting and facilitating discussion on cross-disciplinary geophysical topics, including atmospheric and ocean sciences; solid-Earth sciences; hydrologic sciences; and space sciences.

You might find us at one of these sessions:

Managing Multifunctional Watersheds for the 21st Century (GC052)

A changing climate and growing population will lead people to demand more and potentially different watershed services, including water resource regulation, energy generation, and geomorphic hazard reduction. Green solutions such as watershed restoration and improved agricultural practices have been shown to have important benefits for local livelihoods and biodiversity. These solutions are a corrective to grey infrastructure such as dams and levees that provide valuable services but may also produce major environmental externalities. However, alone these green solutions may not provide the magnitude of services required. We invite submissions showcasing both exemplary case studies and systematic cross-site analyses addressing key questions for an integrated and strategic  management of multifunctional watersheds:  (1) at what scales and contexts do green solutions provide tangible benefits to society; (2) and how can  combined  grey and green infrastructure portfolios be designed to maximize benefits for both nature and people?

Biophysical Processes of Rivers Under Extreme and Changing Conditions (EP006)

Rivers are naturally dynamic systems, characterized by a suite of biophysical processes that are regularly subject to exogenous factors. Under ranges of natural variability, the physics and biota of rivers are resilient to external changes. However, river basins globally are undergoing landscape-scale changes. These changes, which are associated with widespread land use, water management, and climate change, can fundamentally alter biophysical processes. This session focuses on the science and management of integrated biophysical processes in river systems undergoing changing variability, including greater and/or more frequent extremes. Topics may address questions such as: How do changing and extreme events (e.g. streamflow magnitude, frequency, timing, temperature) influence river processes or form and resultant ecosystem structure and function (e.g. habitat quality and availability, egg survival, food webs, algal blooms)? How should management and restoration of rivers be designed and prioritized to mitigate and/or be resilient to these large-scale changes?

Managing and Modeling Tradeoffs and Challenges of Environmental and Low Flows in the 21st Century. (H094)

Rivers are the main source of water, food and energy for billions of people, but the (mis-)management of this critical resource has deteriorated aquatic ecosystems globally. Quantifying how much flow is needed to maintain the ecological integrity of rivers, especially during low flow periods, has become a point of conflict and convergence, particularly in arid regions where most large rivers are regulated. Better managing tradeoffs between environmental flows and consumptive demands requires an improved understanding of watershed hydrology and the low flow characteristics of riverine systems, along with cascading effects on fluvial geomorphology, aquatic ecology, and social systems. This session invites contributions demonstrating recent advances in understanding and resolving competing water demands together with methodological advances on novel ways to define and simulate low flows. We invite contributions that bridge across scientific disciplines and that represent a diversity of regions around the world where water management conflicts are emerging.

Reservoir Sedimentation in Disturbed Landscapes: A Real Look at Lost Water Storage and Fish Passage Opportunities (EP033)

Aging infrastructure and loss of water storage capacity due to sedimentation will cause the social, economic, environmental, and political importance of reservoirs to increase progressively. Reservoirs provide flood control, water supply, and power generation but may hinder survival of anadromous fish. Sediment regimes in disturbed and contaminated landscapes, including the hydraulic mining-impacted Sierra Nevada, complicate efforts to restore storage capacity due to concern about contaminant mobilization. The best available science on mercury fate and transport can stimulate new discussion about sediment removal and maintenance activities. Measures to address sedimentation at reservoirs nearing total storage loss need to be identified and solutions evaluated, including installation of upstream traps, sediment pass-through, flushing or mechanical removal. Site-specific reservoir sedimentation surveys that account for unique sediment regimes of disturbed landscapes are needed to inform cost-benefit analysis of maintaining aging infrastructure at the expense of restoring volitional fish passage.


You are invited to submit an abstract for a presentation or poster to any of these sessions;  the abstract submission deadline is 31 July 2019 23:59 EDT/03:59 +1 GMT.


News on combined planning of dams and renewable energy systems

As demand for clean energy soars across many developing nations, governments face difficult decisions. Should they spend billions of dollars on hydropower, or invest in emerging solar, wind and energy-storage technologies? With the price of renewable energy dropping over the past decade, strategic replacement of energy from future dam sites with renewable energy sources is becoming more economically viable.

UC Berkeley Riverlab PostDoc Alum Rafael Schmitt, with collaborators Noah Kittner, Mathias Kondolf, and Daniel Kammen, had the opportunity to highlight this vision in Nature, as a call to action for the participants of the bi-annual International Hydropower Congress. This article describes how low-carbon alternatives to hydro power can be coupled with strategic dam planning to maximize free-flowing rivers while providing low-carbon energy.

Schmitt, R. J. P., Kittner, N., Kondolf, G. M., & Kammen, D. M. (2019). Deploy diverse renewables to save tropical rivers. Nature, 569(7756), 330.
New study: Estimating the benefits of widespread floodplain reconnection for Columbia River Chinook salmon
We are excited about a recent study co-authored by RiverLab masters student Tyler Nodine, which was recently published by the Canadian Journal of Fisheries and Aquatic Sciences!
Using a combination of remote sensing and machine learning algorithms, the study estimates the potential benefit of floodplain reconnection throughout the Columbia River Basin (CBR) to Chinook salmon (Oncorhynchus tshawytscha) parr. The study found that connected floodplain width was the most important factor for determining side channel presence, and estimated a 26% decrease in side channel habitat area from historical conditions. Reconnection of historical floodplains currently used for agriculture could increase side channel habitat by 25% and spring Chinook salmon parr total rearing capacity by 9% over current estimates.
This publication came out of the Tyler’s work at NOAA at the Northwest Science Center. The paper is  can be downloaded directly here.
Bond, M. H., Nodine, T. G., Beechie, T. J., & Zabel, R. W. (2018). Estimating the benefits of widespread floodplain reconnection for Columbia River Chinook salmon. Canadian Journal of Fisheries and Aquatic Sciences, 1–15.