Tech Briefs

Global mean CO2 concentration does not affect flood magnitude

Increasing global mean CO2 concentration in the U.S. is not resulting in increased flood magnitudes, according to a recent report by U.S. Geological Survey scientists.

This report, published in the online edition of Hydrological Sciences Journal, attempts to quantify the changes taking place in flood behavior in the coterminous U.S. as a function of greenhouse gas concentrations. It is thought that greenhouse gases lead to atmospheric warming, which increases the water-holding capacity of the atmosphere, potentially changing the amounts of precipitable water. The resultant warming also changes: the form of precipitation (more rain and less snow), the timing of snowmelt, potentially storm tracks, and possibly the frequency and intensity of large-scale ocean/climate conditions, the report says.

However, streamflow data consisting of annual flood series from 200 USGS stream gauges of at least 85 years length (through water year 2008) shows no significant relationship between increased global mean CO2 and increased flood magnitudes. This data was taken from basins with little or no reservoir storage or urban development, to rule out human influences associated with large numbers of small impoundments and changes in land use. Over the study period, global mean CO2 increased 32%.

The U.S. was divided into four regions: Northeast, Southeast, Northwest and Southwest. Researchers did note decreased flood magnitudes in the Southwest.

Authors Robert M. Hirsch and K.R. Ryberg say it is crucial that analysis of the empirical data be conducted repeatedly, as this may reveal patterns their analysis was unable to discern.

To view the full article, visit

Reclamation honors Strombach as Engineer of the Year

Mechanical engineer Mike Strombach was named the Pacific Northwest Region’s Engineer of the Year by the U.S. Department of Interior’s Bureau of Reclamation for his work at the 6,809-MW Grand Coulee project in eastern Washington.

Strombach was recognized for his proactive approach to increasing operating efficiencies, improving safety at Grand Coulee Dam and setting a standard for professionalism in the engineering organization, according to a Reclamation release.

He has also developed a training program for incoming apprentices and is noted as the inventor of a vortex generator/cavitation avoidance device that is being tested inside scroll cases and turbine runners at the dam.

Grand Coulee Dam, part of the Columbia Basin Project, is the largest hydroelectric project in terms of generating capacity in the U.S.

EPRI releases report on Alden turbine testing

The Electric Power Research Institute (EPRI) announces availability of a new technical update, “Fish Friendly” Hydropower Turbine Development and Deployment: Alden Turbine Preliminary Engineering and Model Testing.

This report presents the results of a collaborative research project funded by EPRI, the U.S. Department of Energy, and hydropower industry partners, with the objective of completing the remaining developmental engineering required for a “fish-friendly” hydropower turbine. This turbine, called the Alden turbine, was developed by Alden Research Laboratories.

Earlier engineering and research, started in 1995 and completed in 2008, established a viable conceptual design. Additional engineering completed in 2009 and 2010 included converting a conceptual design with the use of computational fluid dynamics into a machine design that can be built and constructing and testing a physical model of the turbine to evaluate its performance characteristics for economic analysis and mechanical layout.

Completion of these efforts provides a mechanical and electrical design that can be readily adapted to site-specific conditions with additional engineering development comparable to costs associated with conventional turbine designs, EPRI says.

The information provided in the report will be of value in planning new development, adding capacity to existing projects and non-powered dams, harnessing lost power associated with minimum flow and non-turbine discharges for downstream fish passage, and even retrofitting where existing downstream fish passage mortality associated with conventional turbine operation is unacceptable to licensing stakeholders, EPRI says.

EPRI is preparing for the next phase of the turbine’s development, installation and testing. EPRI is involved in the early stage planning of two demonstration projects, one in the U.S. and one in France. EPRI plans to launch supplemental project opportunities to support both efforts.

The report can be downloaded for free at

Alstom opens hydroelectric power research facility in Canada

Alstom recently inaugurated the company’s newest Global Technology Center (GTC) in the Canadian town of Sorel-Tracy. The center will focus on hydroelectric power.

Housed within Alstom’s existing North American hydro headquarters manufacturing and engineering facility, Alstom said the GTC will serve as the company’s global hub for innovation in hydro retrofit processes and technology.

The Sorel-Tracy GTC houses a team of Alstom research experts and engineers working with industry and academic partners to study improvements in retrofit techniques that can improve plant performance, availability and reliability without increasing overall plant size or environmental impact.

Site offers access to generator expertise, including hydro

The International Generator Technical Community is an online forum of engineers worldwide discussing the operation and maintenance of generators.

The site, founded and launched by National Electric Coil in March 2010, is available at

With nearly 800 members in more than 54 countries, this forum provides in-depth knowledge and discussions regarding generators for thermal and hydro units. Members include engineers and professionals responsible for power plant generators, independent consultants and technical resource providers.

Each specific forum on the site is monitored and maintained by volunteer experts, called moderators. Topics covered in the forums include rotor electrical testing, inner hydrogen-cooled windings, generator visual inspections, hydro generators, inner water-cooled windings, rotor windings, vibration monitoring, stator end winding vibration and resonance, rotor mechanical components, exciters, large air-cooled generators, stator electrical testing, and stator core, clamping systems and frame.

Recent topics of discussion include stator winding ac/dc hipot, leakage, absorption tests; running electrical tests such as flux probe, impedance and Meggar; and stator dusting, greasing, wedging and bracing.

In order to preserve the technical integrity of the site, membership is limited to personnel with day-to-day responsibility for stationary generators. Site rules require members to avoid commercially-motivated interactions and stick with technical issues, allowing an atmosphere of genuine problem-solving.

The community offers a resource center for members that contains pdf documents, web links to documents, and other media recommended by community members.

IEEE releases standard on unique identification in hydro facilities

IEEE announces availability of a new standard, Recommended Practice for Unique Identification in Hydroelectric Facilities.

This 47-page standard is intended to provide a unique identification system for hydro facilities. It segregates and incorporates plant, unit, system and component identifiers as a minimum.

The Hydroelectric Power Subcommittee of the Energy Development and Power Generation Committee of the IEEE Power Engineering Society developed the standard.

– The standard can be purchased in pdf form for $65 ($80 non-members) and printed form for $80 ($100 non-members) at;product_id=1814806.

Institute developing sustainability rating system for civil structures

The Institute for Sustainable Infrastructure is working to develop and deliver a civil engineering infrastructure sustainability rating system.

ISI developed an initial version of envision, a voluntary civil infrastructure rating system, with a public comment period from July 2011 through the end of that year. The next step is to use these comments to update the rating system before releasing applications in 2012 that can be used by project teams, owners and agencies for project recognition.

The envision system is intended to be an objective, third-party framework that provides owners, agencies, engineers and others with a comprehensive approach for describing the features and relative performance of sustainable civil engineering projects. Interested groups are invited to use ISI-certified project assessors to assist with the planning and delivery of more effective and efficient solutions and to be considered for project performance recognition through an independent, third-party project verification process, leading to a formal project award at various performance levels.

The specific civil infrastructure being referenced includes roads, bridges, pipelines, railways, airports, dams, levees, solid waste landfills, water supplies, wastewater treatment plants, power transmission lines, telecommunications towers and public spaces. ISI has developed a package of rating systems that can be customized to the specific application and its complexity or magnitude, ranging from the conceptual planning stage through construction, commissioning and operation. These are called Stages 1 through 4, with the higher levels being applicable to highly complex major civil infrastructure projects that have a high political and public interest in whether and how they are constructed.

Although the primary emphasis of envision is focused on needs in the U.S. and Canada, developers drew on a comprehensive review of the state of the art in sustainability rating systems in the U.S. and around the world, including FIDIC and CEEQUAL in the United Kingdom.

ISI was formed in 2010 by the American Society of Civil Engineers, American Council of Engineering Companies and American Public Works Association.

In November 2011, Anastasia Harrison, director of sustainability for Gannett Fleming’s northeast region, was appointed chair of ISI’s accreditation committee, which is responsible for establishing criteria and qualifications for the ISI sustainability professional designation.

The institute is on the Internet at

Pacific Gas and Electric assists in salmon restoration

The Bureau of Reclamation’s Battle Creek Salmon and Steelhead Restoration Project – working in conjunction with Pacific Gas and Electric Co. and the U.S. Fish and Wildlife Service – has resulted in a substantial increase in chinook salmon in California’s North Fork Battle Creek.

FWS has been monitoring levels of threatened chinook salmon for years, and in fall 2011 more than four times the normal number of salmon spawned in recently restored habitat upstream of where the Wildcat Diversion Dam once stood. Construction work on this restoration project began in 2009, and in August 2010 the Wildcat Diversion Dam was removed, restoring about 15 miles of stream habitat. Over the past decade, only about 7% of the chinook nests (called “redds”) were built upstream of the dam. In 2011, fish built 33% of the redds upstream.

PG&E’s cooperation in the project has also been crucial because the company has voluntarily adjusted its hydroelectric production at the 37.9-MW Battle Creek project to better benefit the salmon.

Also on North Fork Battle Creek, fish screen and ladder construction is occurring upstream at PG&E’s North Battle Creek Feeder and Eagle Canyon Diversion Dams and is anticipated to be completed by 2013.

On South Fork Battle Creek, construction of an Inskip Powerhouse bypass and tailrace connector to Coleman Canal (to prevent mixing of water from the two river forks) is anticipated to be completed by the end of 2012. The contract was awarded in July 2010.

The remainder of the restoration project includes construction of a fish barrier weir on Baldwin Creek, fish screen and ladder on Inskip Diversion Dam, and tailrace connector from South Powerhouse to Inskip Canal, as well as removal of the Lower Ripley Creek Feeder, Soap Creek Feeder, and South and Coleman Diversion Dams. PG&E owns all the facilities.

This work is expected to begin in 2013 and be completed in 2015.

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