Author: riverlab

Postdoc position: Assessing ecosystem benefits for hydropower under land use and climate change

The successful candidate will explore impacts of climate and landuse change on a hydropower dam in Peru (recently acquired by a major a Chinese State-owned Enterprise), and evaluate opportunities for catchment management to reduce those impacts. The project is with the Chinese Academy of Sciences, and the position will be shared between Stanford and Beijing. The candidate should be fluent in Chinese and have a background in hydrology or landuse planning. The announcement is here.

REMEMBERING LEWIS MACADAMS AND THE FUTURE OF THE CONCRETE CHANNEL

Poet Lewis Macadams is well-known to river afficionados thanks to his visionary work to respect and restore the Los Angeles River. Founder of the NGO Friends of the Los Angeles River, MacAdams was instrumental in putting the river ‘on the map’ for the public, and ‘on the radar’ of the political life of Los Angeles, leading to the City’s River Master Plan in 1991 and the River Revitalization Master Plan in 2007. MacAdams passed away last April at 75, but the news of his loss was largely eclipsed at the time by the chaos created by the COVID pandemic and economic dislocation. An essay Shall We Gather at the River? published by the Poetry Foundation provides a fascinating biography of MacAdams, tracing his earlier years in New York, Buffalo, and Bolinas, before moving to Los Angeles four decades ago and adopting the river. MacAdams’ book-length poem, The River, is out of print but is worth seeking out from the library until it is reissued.

MacAdams was a featured speaker at (and a key inspiration for) the conference The Future of the Concrete Channel convened by the Department of Landscape Architecture and Environmental Planning in November 2013, organized by Matt Kondolf and Raymond Wong. The conference program featured these topics and speakers:

Policy background Scott Nicholson USACE HQ, Rethinking flood control 23 years later Phil Williams PWA-ESA, Overview of concrete channels around the SF Bay Raymond Wong, UCB, A historical perspective Bill Kier, Kier Associates, Contra Costa County Mike Carlson CCCFC, Santa Clara County Jim Fiedler, SCVWD, Menomonee River David Fowler, Milwaukee MSD, Resonance in contemporary culture Chip Sullivan, UCB, David Fletcher, California College of the Arts, A 50-year plan for Contra Costa Streams Mitch Avalon, CCCFC, The Ala Wai Canal project feasibility study Scott Nicholson, Replacing aging concrete channels David Fowler, MMSD, Los Angeles River Ecosystem Restoration Project Carol Armstrong, City of Los Angeles, Evolving concepts of restoration Lewis MacAdams, FOLAR, Overcoming barriers to reinventing concrete channels Jeff Haltiner, UCB & ESA-PWA, Kathy Schaefer, FEMA, Louise Mozingo, UC Berkeley, Mitch Avalon, CCCFC; Ralph Johnson, Alameda County.

HIGH-FLOW RELEASES FROM DAMS TO RESTORE GEOMORPHIC PROCESSES, AQUATIC HABITATS: NEW PUBLICATION AVAILABLE

Deliberate high-flow releases are increasingly made from dams to mimic effects of floods and interact with the channel to produce biophysical changes in channel characteristics, such as removing fine sediment from downstream aquatic habitats. These are a special case of environmental flows intended to mitigate geomorphic/ecological effects of dams, commonly termed flushing flows. In a new publication, Remi Loire and colleagues propose new terms for these high flow releases: morphogenic releases, or ecomorphogenic releases for flows intended specifically to improve aquatic and riparian habitats. The paper, published in Earth Science Reviews, reviews objectives of these flows, experiences gained from their implementation, and potential conflicts with environmental, socio-economic, and dam-operational issues. The paper is available until 21 February 2021 for free download here.

Loire, R, H Piégay, J-R Malavoi, GM Kondolf, and LA Bêche. From flushing flows to eco-geomorphic flow releases: evolving terminology, practice, and integration into regulated river management. Earth Science Reviews 213: 103475

WHY URBAN RIVERFRONT RENEWALS OFTEN FAIL

Many cities worldwide now have available waterfront land, often in the city center, thanks to de-industrialization and concentration of navigation elsewhere. As cities seek to take advantage of this remarkable real estate, they may be prone to some classic ‘traps’ such as copying projects successful in another city but which fail in the new location due to differences in scale, topography, urban form, etc. In this recent publication, Pedro Pinto and Matt Kondolf present an idiosyncratic list of ‘wrongs’ that are evident in many such projects. The paper is freely available, via open access here.

Pinto, JP, and GM Kondolf. 2020. The fit of urban waterfront interventions: matters of size, money and function. Sustainability 12: 4079; doi:10.3390/su12104079

Figure 1. Viana do Castelo, Portugal: three recently built, out-of-scale public buildings cut off the old town from the Lima riverbanks. (source Google)
THE IDEAL MEANDER: WHY DO RIVER RESTORATION PROJECTS ALWAYS SEEK TO BUILD IDEAL MEANDERS? KRISTEN WILSON SUGGESTS IT’S UNDERLYING AESTHETIC PREFERENCES

River restoration projects in North America that involve reconfiguration of stream channels are dominated by symmetrical, single-thread meandering channels.  Although the meander dimensions are commonly justified by relations between channel width and meander wavelength, the universal preference for single-thread meandering channels in restoration projects is rarely questioned.  The aesthetic appeal of s-shaped curves in art and landscape design may help explain the prevalence of this form in river restoration projects. Riverlab alumna Kristen Wilson (Nature Conservancy) gave 300 freshwater scientists attending her keynote talk 5 minutes to draw a restored stream.  She compiled the results to see what mental images these scientists had for restored channels. Most depicted single-thread meanders for their restored channel, although there were interesting variants.  See Kristen’s just-published paper here.

 

Figure 1. The ideal meander with its repeating, regular, and symmetrical bends as drawn by select respondents, isolated to the channel pattern, and overlaid to emphasize the similarity in the form. A.—One wavelength. B.—1.5 wavelength. C.—Two or more wavelengths drawings.
NEW PUBLICATION: DOCUMENTING EFFECTS OF EROSION FROM ROAD CONSTRUCTION ON A CENTRAL AMERICAN RIVER

Throughout the humid tropics, increased land disturbance and concomitant road construction increases erosion and sediment delivery to rivers.  Building road networks in developing countries is commonly a priority for international development funding based on anticipated socio-economic benefits. Yet the resulting erosion from roads, which recent studies have shown result in at least ten-fold increases in erosion rates, is not fully accounted for.  While effects of road-derived sediment on aquatic ecosystems have been documented in temperate climates, little has been published on the effects of road-induced sediment on aquatic ecosystems in developing countries of the tropics.  Along the south bank of the Rio San Juan (Nicaragua and Costa Rica), attempts to build a road without engineering or plans resulted in massive failures and erosion in areas where steep slopes impinge upon the river bank.  Pre-existing tributary streams received elevated sediment loads, creating new deposits on pre-existing tributary deltas.  In some reaches with rapidly eroding sites, completely new deltas of freshly deposited sediment were formed, prograding into the river channel.

Riverlab alumni Blanca Rios and Scott Walls joined with Matt Kondolf to study periphyton biomass and macroinvertebrate communities on the deltas of Río San Juan tributaries, comparing north-bank tributaries draining undisturbed rain forest with south-bank tributaries receiving runoff from the partially-built road experiencing rapid erosion. Periphyton biomass, richness and abundance of macroinvertebrates overall, and richness and abundance of Ephemeroptera, Plecoptera and Trichoptera were higher on the north-bank tributary deltas than the south-bank tributary deltas. These findings were consistent with prior studies in temperate climates showing detrimental effects of road-derived fine sediment on aquatic organisms.  A Non-Metric Multidimensional Scaling (NMDS) analysis showed the impacted community on the south-bank deltas was influenced by poorly-sorted substrate with greater proportions of fine sediment and higher water temperatures.  The paper is freely available (open-access) here.

Rios-Touma, B, GM Kondolf, and SP Walls. 2020. Impacts of sediment derived from erosion of partially-constructed road on aquatic organisms in a tropical river: the Río San Juan, Nicaragua and Costa Rica. PLoSONE 15(11):e0242356. https://doi.org/10.1371/journal.pone.0242356

Figure 1. Reach of Rio San Juan from approximately River Km 83.3 to 84.3 (downstream of the outlet of Lake Nicaragua)
Figure 2. Macroinvertebrate richness of south-bank versus north-bank tributary deltas of the Rio San Juan, MarchMay 2014.
GEOMORPHIC & ECOLOGICAL FUNDAMENTALS FOR RIVER & STREAM RESTORATION CANCELLED FOR 2020 DUE TO COVID-19, BUT ON FOR 16-20 AUG 2021

With great regret, we cancel the 2020 shortcourse at Sagehen Creek Field Station, due to the many complications arising from the CVID-19 pandemic and the challenges in avoiding problems in holding the shortcourse at the station.  Those already registered are entitled to a full refund or may defer their participation to next year’s course offering, 16-20 August 2021.   We apologize for this very disappointing news, but look forward to better conditions under which we can once again hold the course next year.  We thank you for your understanding.

 

Matt Kondolf and the Sagehen Teaching Team

Geomorphic and Ecological Fundamentals for River and Stream Restoration

EPA Watershed Management Postgraduate Research Opportunity
DEADLINE: May 29, 2020
Office of Water | Washington, DC | Full-time | MONTHLY STIPEND PROVIDED

This opportunity will provide excellent exposure to the interface of watershed technical issues and environmental policy. It also offers exposure to the interaction between State and EPA CWA program practitioners in implementing their respective responsibilities under the CWA 303(d) program. Under the guidance of a mentor, the research participant will be involved in the activities above and will learn: (1)The respective roles of EPA, states and tribes in achieving the goals of the Clean Water Act (CWA) to achieve and maintain water quality; (2) Programmatic approaches and policy and technical tools to identify and develop restoration and protection plans for impaired or high quality waters, including those related to address nutrient impairments; (3) How states and EPA can continue to push the CWA 303(d) listing and TMDL program to better achieve environmental results in ways tailored to specific state priorities; (4) How to leverage different media to convey water quality information to a variety of audiences.

>>Job description

HYDROLOGIC IMPACTS OF UPSTREAM DAMS ON THE MEKONG DELTA

You may be interested in a new analysis of the effects of recently completed Xayaboury Dam (on the Mekong mainstem near Luang Prabang) and a cascade of dams upstream in China on flow patterns in the Lower Mekong River. The paper, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020 by Nguyen Ngoc Tran was published in Vietnamese in TIA SANG, a scientific journal published by the Ministry of Science and Technology. The English version is now available here. As illustrated in excerpts of Figures 5 and 6 from the paper, the hydrologic analysis shows that flows this dry season have been significantly lower than in prior years’ dry seasons.

Riverlab members have contributed scientific papers on the cumulative effects of upstream dams on the sediment budget of the Mekong Delta and other threats to the sustainability of the Delta (Kondolf et al 2014, Kondolf et al 2018) and the potential for strategic dam planning to minimize impacts of dams on downstream sediment budgets and fish migration (Schmitt et al 2019).


Water levels in the Mekong River at Nakhon Phanom reflecting severe drought conditions in the current dry season of the 2019-2020 water year. (Source: Nguyen Ngoc Tran. 2020, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020, Figure 5.)


View of the exposed bed of the Mekong River at Nakhon Phanom in late October 2019, reflecting severe drought conditions in this year’s dry season. (Source: Nguyen Ngoc Tran. 2020, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020, Figure 6.)

References Cited

Kondolf, G.M., Z.K. Rubin, J.T. Minear. 2014. Dams on the Mekong: Cumulative sediment starvation.  Water Resources Research 50, doi:10.1002/2013WR014651. >>link to paper

Kondolf, GM, RJP Schmitt, P Carling, S Darby, M Arias, S Bizzi, A Castelletti, T Cochrane, S Gibson, M Kummu, C Oeurng, Z Rubin, and T Wild. 2018. Changing sediment budget of the Mekong: Cumulative threats and management strategies for a large river basin. Science of the Total Environment 625: 114-134. https://doi.org/10.1016/j.scitotenv.2017.11.361 >>link to paper

Schmitt, R, S Bizzi, AF Castelletti, J Opperman, GM Kondolf. 2019. Planning dam portfolios for low sediment trapping shows limits on sustainable hydropower in the Mekong. Science Advances 5: eaaw2175 >>link to paper