Northwest Hydro System

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This case study presents the Northwest Hydro System (NwHS), which is situated in the northwestern United States (the Northwest). NwHS comprises a large number of loosely coupled autonomous elements (hydroelectric dams) that operate in a complex environment of social, regulatory, and ecological contexts. It is instructive to note that the NwHS is characterized as a project that is concerned with planning, developing, and maintaining a hydroelectric system that has evolved, and continues to evolve, over time. Each of the hydroelectric dams within the NwHS is also referred to as a project, which indicates that the individual elements of the NwHS are also evolving over time (FWEE 2016).


As is shown in this case study, NwHS is an adaptive and reconfigurable system that exists within a framework of policies, rules, regulations, and agreements. The NwHS is analyzed using each of the four provisioning paradigms in SEBoK Part 4: product system engineering; service system engineering; enterprise system engineering; and system of systems engineering.

NwHS encompasses the Columbia River and its tributaries. The headwaters of the Columbia are in the Rocky Mountains of British Columbia, Canada. The river flows south into the United States and then east to west; it forms the north-south border between the states of Washington and Oregon in the U.S. and empties into the Pacific Ocean near Astoria, Oregon. The Columbia River drainage basin (Columbia and tributaries) is roughly the size of France and extends across seven U.S. states and British Columbia (Col 2016).

The Columbia River has 14 hydroelectric dams (hydro dams) on its main stem. In total, there are more than 250 hydro dams in the Columbia River Basin, each of which has a generating capacity of five or more megawatts of electricity. The NwHS produces approximately one-third of all hydroelectric power generated in the United States - more than any other North American hydroelectric system. The amount of electrical power generated by the NwHS fluctuates between 50% and 75% of all electricity used in the Northwest; other sources include coal, natural gas, nuclear, wind, and solar. Excess electrical energy generated by NwHS is sold to other electrical grids. There are more small hydro dams than large dams. Small hydro dams have a generating capacity of 100 kilowatts to 30 megawatts; large hydro dams have a capacity of more than 30 megawatts. In addition, there are numerous micro dams that each can generate fewer than 100 kilowatts. Most micro dams provide power to isolated homes or small communities but some are elements of the NwHS and sell power to utilities (DOE 2016). Utility companies own some of the dams, some are locally and privately owned, and some are owned and operated by federal agencies.

The Bonneville Power Administration (BPA) provides about one-third of the electrical power generated by NwHS and used in the Northwest; BPA is a federal nonprofit agency – it is part of the U.S. Department of Energy. It is self-funded and covers its costs by selling electrical power generated by 31 federal hydro dams in the Columbia River Basin. The U.S. Army Corps of Engineers and the Bureau of Reclamation operate the dams.

The Bureau of Reclamation also operates a network of automated hydrologic and meteorologic monitoring stations located throughout the Northwest. This network and its associated communications and computer systems are collectively called Hydromet. Remote data collection platforms transmit water and environmental data via radio and satellite to provide near-real-time water management capabilities. Other information, as available, is integrated with Hydromet data to provide timely water supply status for river and reservoir operations (USBR 2016).

Distinguishing characteristics of individual hydro dams are their capacity to generate electrical energy and their physical structure. Several factors contribute to the differences in generating capacity of hydro dams: the number of turbines/generators; the flow rate of a river or tributary; the amount of elevation that water falls in order to spin the turbines; and environmental factors such as providing for fish passage and regulating water flow to provide irrigation water and maintain downstream ecosystems.

Dam structures include storage dams, run-of-river dams, and pumped storage dams (DOE 2016). A storage dam retains water in a reservoir for future use. A run-of-river dam harvests the energy in a river as it flows through the dam but does not impede the flow. Pumped storage dams use generated electricity to pump water back up to a storage reservoir during times of low demand for use during times of high demand. Pumped storage dams are not common in the NwHS.


NwHS has three primary goals (NwHS 2016):

  1. To provide most of the Northwest’s “firm-energy” needs.
  2. To maximize “non-firm” energy production.
  3. To maintain the ecological environment.

Firm energy is the amount of electricity the Northwest will need each year. Planners rely on NwHS and other sources to produce enough firm energy to ensure that sufficient electricity will be generated to meet estimated needs (energy sources include hydroelectric, nuclear, coal, natural gas, solar, and wind). NwHS “firm energy” is the amount of electricity than can be generated by NwHS when the amount of available water is at a historical low, thus guaranteeing the amount of energy the NwHS can provide.

Non-firm energy is the electricity generated when the annual hydrologic cycle makes more water available for power generation than in a historically low-water year. Non-firm electricity generated by hydro dams is generally sold at a lower price than the alternatives of electricity generated by nuclear, coal, or natural gas thus making it more attractive to customers. Excess non-firm electricity is also sold to interconnected regional grids when the demand on those grids exceeds supply.

Other goals for NwHS include flood control, navigation, irrigation, and maintaining the water levels of all reservoirs.


The NwHS is a large, complex system that has many challenges to be met.

NwHS hydro dams have varying design details (e.g., the types of turbines, generators, control systems, and fish passage facilities used). This makes routine maintenance, retrofitting, and other sustainment issues unique for each dam.

Safety and security (both physical and cyber) are common challenges for all dams; cyber security is a growing concern. Smaller dams, having fewer resources, may be more susceptible to cyber attacks than larger ones. It has been reported that on 12 occasions in the last decade hackers gained top-level access to key power networks (HLS 2010) (Cyber 2015).

Run-of-river hydro dams do not store water. They may not be able to meet their firm energy commitments when rivers are lower than anticipated and flowing slowly.

The ways in which electricity generated by a dam is transmitted and sold to utilities and large industrial customers varies widely. For instance, the Bonneville Power Administration transmits and sells power generated by federal dams. Non-federal operators must manage transmission and sale of power produced by their dams.

Depending on factors such as size, structure, location, and ownership of each dam, a large number of policies, regulations, and agreements have dramatically different effects on how dams are operated.

Some of the most contentious environmental issues are associated with maintaining the ecology of the rivers, preserving salmon and other fish, and providing sufficient irrigation water while preserving sufficient reservoir water to meet firm-energy demands (Speakout 2016).

Preserving the salmon population endangered by dams is a continuing challenge. Salmon populations have been depleted because dams impede the return of salmon to upstream spawning beds. Native Americans advocate for their traditional fishing rights, which conflict with governmental policies intended to maintain healthy salmon populations in the Columbia River Basin (Impact 2016). The National Marine Fisheries Service has recently declared that salmon recovery is a higher priority than all other purposes except flood control at 14 federal dams.

Systems Engineering Practices

The Northwest Hydro System is a large, complex system composed of loosely coupled autonomous elements; each dam operates semi-independently within a large network of similar entities and contextual constraints. The NwHS evolves over time: some dams have been retrofitted to increase power generation capability or to reconfigure connections to electrical transmission lines; new dams have been constructed; and some existing dams have been decommissioned and removed.

Human elements of NwHS include: operators; maintainers; regulators; and inspectors. Others are suppliers to NwHS (vendors and contractors); some humans are users of the electricity generated by NwHS (businesses and home owners); and some are stakeholders who depend on and are impacted by the NwHS (utilities, large industries, farmers, ranchers, homeowners, ecology advocates, Native Americans, towns).

The context of NwHS includes natural elements (rivers, terrain, weather systems, fish); elements purposefully built by humans (transmission lines, electrical grids); cyber connections (both wired and Internet); and rules, regulations, and agreements at the federal, regional, state, and local levels.

Given the complexity of the NwHS and its context, it is instructive to analyze the NwHS by applying each of the four application paradigms of systems engineering presented in SEBok Part 4: the product, service, enterprise, and system-of-systems application paradigms.

Product system provisioning

Product system provisioning applies systems engineering processes, methods, tools, and techniques to conceive, develop, and sustain the purposefully developed elements of a system (e.g., a hydro dam or a hydro system). In addition, some of the naturally occurring physical elements of a system may be shaped and configured (e.g., a river channel).

Major product elements of a hydro dam include the physical structure of the dam (including the spillway), the penstock (used to direct water into the turbines), the generating plant (i.e., the turbines used to turn generator rotors, generator stators and rotors that generate the electricity, step-up transformers used to increase the voltage level of electricity produced by the generators, and connections to transmission lines).

Cyber elements sense, measure, regulate, and control water flow, power generation, safety, security, and the structural integrity of the dam. Some turbines, for example, have adjustable vanes that are controlled to harvest maximum energy from the water, depending on the flow rate, power demand, and other factors. The cyber elements include: computing devices; supporting software (operating systems, databases, spreadsheets); data management software (collection, analysis, reporting); application software (displays of monitored status and interfaces for controlling operation of a dam); and communication interfaces to wired linkage and Internet-enabled links. In addition, software support is provided for the analog and digital devices needed to sense, measure, regulate, and control the purposefully built and naturally occurring elements of a dam and its environment.

Product system provisioning is also concerned with other issues that apply to individual dams, elements of dams, and the overall NwHS. They include issues such as: manufacturability/producibility; logistics and distribution; product quality; product disposal; conformance to policies, laws, regulations, agreements, and standards; value added for stakeholders; and meeting customer’s expectations. Many different technologies and engineering disciplines are needed to develop and sustain a hydro dam and the overall Northwest Hydro System. Product system provisioning can provide the coordination and control of systems engineering needed to develop, reconfigure, adapt, analyze, and sustain the hydro dams and the NwHS.

Service system provisioning

A service is an activity performed by an entity to help or assist one or more other entities. Service system provisioning can be applied within the various contexts of services provided by the NwHS to meet stakeholders’ requirements, users’ needs, and system interactions with operators, users, and maintainers, plus the interactions with the contextual elements that determined services provided by the NwHS in the social, business, regulatory, and physical environments.

The NWHS provides electricity to a grid that serves commercial, industrial, governmental, and domestic customers. Stakeholders in addition to customers served include those who affect or will be affected by development, operation, and sustainment of a dam. Downstream stakeholders served, for example, include, Native Americans, farmers and ranchers, and communities that receive the service of water released by the dam.

Additional service attributes include: the services that enable operators and maintainers to efficiently and effectively operate and maintain the physical and cyber elements of a dam; release water from the dam in a manner that services the upstream and downstream ecosystems; manage sharing of electrical power with other regional grids; provide emergency responses to power demands that result from electrical brownouts, blackouts, and overloads; and handle system failures that might be caused by earthquakes, terrorist attacks, and other catastrophic events.

Enterprise system provisioning

An enterprise, such as the NwHS, consists of one or more organizations that share a mission, goals, and objectives to offer an output such as a product or service. The mission and goals of the NwHS are to provide most of the Northwest’s firm energy needs and to maximize non-firm energy production while serving stakeholders and preserving affected environmental ecosystems. To meet those goals, the Northwest Hydroelectric Association (NWHA) coordinates the planning, design, improvement, and operation of the hydro dams that constitute the NwHS enterprise.

NWHA members represents all segments of the hydropower industry – independent developers and energy producers; public and private utilities; manufacturers and distributors; and local, state and regional governments including water and irrigation districts. Other NWHA members include contractors, Native American tribes, and consultants: engineers, financiers, environmental scientists, attorneys and others (NWHA 2016).

Note that an enterprise may consist of multiple organizations that are engaged in a common endeavor. The NwHS is a large complex enterprise that has many constituent organizations; namely, the organizations that own and operate the hydro dams and the other stakeholder members of the NWHA. Differences in ownership, structure, location, and size of hydro dams, the special interests of various NWHA members, and a complicated regulatory process, are some of the distinguishing characteristics of the NwHS that can be analyzed by enterprise systems provisioning.

System of Systems provisioning

Many systems are composed of autonomous elements that are combined to provide increased capabilities that cannot be provided by the elements operating in isolation. The Northwest Hydro System is a system of systems comprised of autonomous hydro dams that have different owners, different operators, different stakeholders, and different regulators. The autonomous hydro dams could not provide the NwHS capabilities without the overall coordination and control that can be managed by applying system of systems provisioning.

Lessons Learned

NwHS is a collection of many interrelated ongoing projects that have shared common goals and shared constraints. The unique characteristics of NwHS make it a useful case study to illustrate how the four provisioning paradigms in SEBoK Part 4 provide essential viewpoints for analyzing large complex systems comprised of loosely coupled, autonomous elements.

Product systems engineering allows the collection of physical and purposefully built NwHS elements and their interconnections to be analyzed by applying systems product engineering processes and methods.

Service systems engineering supports analysis of the NwHS services provided to customers, users, farmers, ranchers, Native Americans, and other stakeholders who rely on NwHS for those services.

Enterprise systems engineering considers the broad scope and impact of the NwHS enterprise, both positive and negative on the northwestern United States within the context of economic, social, physical, and regulatory environments.

System of Systems engineering applies the principles of planning, coordination, and operation to a collection of semi-autonomous hydro dams that form the Northwest Hydro System. The complexity of adding new dams as well as modifying and decommissioning existing dams in a seamless manner can best be understood by applying system of systems engineering processes and methods.

Taken together, the four provisioning paradigms in SEBoK Part 4 present a comprehensive view of a very large complex system whose many dimensions would be otherwise difficult, if not impossible, to comprehend when the NwHS is examined using only one of the paradigms.


Works Cited

Col. 2016. Columbia River. Available at Accessed February 15, 2016..

Cyber. 2015. US in Fear of New Cyber Attack. Available at Accessed February 16, 2016.

DOE. 2016. Types of Hydropower Plants. Accessed February 16, 2016. Available. FWEE. 2016. Foundation for Water and Energy Education. Accessed February 17, 2016. Available: HLS. 2010. Dam Sector Roadmap to Secure Systems. Available at Accessed February 16, 2016.

Impact. 2016. The impact of the Bonneville Dam on Native American Culture. Available at Accessed February 16, 2016.

NWHA. 2016. Northwest Hydroelectric Association. Available at Accessed February 17, 2016.

NwHS. 2016. How the Northwest Hydro System Works. Available: Accessed February 15, 2016.

USBR. 2016. Hydromet. Available at Accessed February 16, 2016.

Speakout. 2016. Stop the Hydropower Wish List Bill. Available: Accessed February 16, 2016.

Primary References

FCRPS. 2003. Federal Columbia River Power System. Available at Accessed February 16, 2016.

HLS. 2010. Dam Sector Roadmap to Secure Systems. Available at Accessed February 16, 2016.

NWHA. 2016. Northwest Hydroelectric Association. Available: Accessed February 17, 2016.

NwHS. 2016. How the Northwest Hydro System Works. Available: Accessed February 15, 2016.

Additional References

FWEE1. 2016. Foundation for Water and Energy Education. Available: Accessed February 16, 2016.

FWEE2. 2016. Overview of Hydropower in the Northwest. Available: Accessed February 16, 2016.

HP. 2016. Hydro Portal. Available at Accessed February 16, 2016.

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