Ensuring water is available for river management and hydro generation

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Using lessons gleaned from work on the Roanoke River in the U.S., The Nature Conservancy is creating an approach that can benefit both hydropower project operators and other water resource stakeholders.

Ensuring there is enough water in the right places and at the right times of year is complicated.

For those managing rivers for hydropower generation, challenges lie in variable hydrology that must be balanced for energy generation and flood management.

For those seeking to restore rivers and floodplains, there are other elusive aspects to consider — particularly the pattern of flow. Rate, duration and seasonality of flows shape floodplains, riparian habitat and species life cycles and changes.

Given this complexity, forging agreements to both balance river management functions and restore ecosystems must be impossibly complex. Right? Complex, yes. But as illustrated by a pair of breakthrough agreements on the Roanoke River in the U.S. in 2016, not impossible.

Located on the Virginia/North Carolina border, John H. Kerr Dam creates one of the largest reservoirs in the southeastern U.S.

Realizing water and land connections

The Roanoke River rises in the Blue Ridge Mountains of Virginia and flows southeast for 410 miles into North Carolina’s Albemarle Sound. At the Virginia/North Carolina border, John H. Kerr Dam, operated by the U.S. Army Corps of Engineers, forms Kerr Lake. With 3.36 million acre-feet of storage, this is one of the biggest reservoirs in the southeast U.S.

Kerr Dam is managed primarily for flood-risk reduction and hydropower generation (with a capacity of 227 MW). Downstream of Kerr Dam, Dominion Power operates two dams and associated hydroelectric power facilities, Gaston (224 MW) and Roanoke Rapids (95 MW). The lower two dams operate largely as “run-of-Kerr,” that is, they pass through the flow regime released from the upstream Kerr Dam.

Below the three dams, the Roanoke River meanders 137 miles through a vast floodplain, one of the largest bottomland forests in the U.S. Massive bald cypress and tupelo trees line the channels and low-lying flats, while oak and hickory occupy higher ground. The forests harbor black bear and several rare or endangered species. The river is particularly notable for its spring runs of striped bass, shad and river herring. The Nature Conservancy identified the Roanoke River’s floodplain forest as a conservation priority in the early 1980s. Since then, it has worked with partners to protect 95,000 acres.

As the Conservancy began to manage large areas of the Roanoke floodplain, its scientists recognized that land protection alone was not sufficient to maintain the forest. Over the long term, a healthy floodplain forest depends directly on the river — specifically its flow patterns. While floodplain tree species generally thrive in areas exposed to periodic flooding, those species still require periods of dry soil to regenerate. The business-as-usual operations of upstream dams at the time had changed the Roanoke’s flow regime downstream such that regeneration of forest species, including oak and hickory — which are particularly valuable for wildlife — was greatly reduced.

The problematic alterations were the result of management of the upstream dams for both flood control and hydropower. To avoid spilling water at the downstream dams, Kerr was holding back floodwaters and releasing them over time, converting larger, shorter floods into smaller, longer ones that created extended periods of floodplain inundation. Management for within-week peaking at the Dominion dams exacerbated this problem of long-period inundation.

Changing the dynamics of river collaboration

The Conservancy and other partners agreed it was critical to collaborate with dam operators to find a solution that worked for people and nature. The Dominion dams’ operating licenses from the Federal Energy Regulatory Commission (FERC) were set to expire in 2001 and, in 1995, Dominion initiated an Alternate Licensing Process (ALP) — an approach FERC had recently created to promote stakeholder engagement — and a settlement agreement to support the license application.

An agreement was reached in 2003, and Dominion received new licenses for Gaston and Roanoke Rapids in 2004. The settlement and license included an adaptive management program in which Dominion — through a cooperative management team of stakeholders including the North Carolina Wildlife Resources Commission, North Carolina Division of Water Resources, U.S. Fish and Wildlife Service, and representatives from local governments — would study and assess its peaking operations over a five-year period. Results from this research would inform Dominion’s management and initiate another five-year cycle of monitoring and assessment.

The Conservancy had begun work with HydroLogics in 1994 to develop a flow model for the lower Roanoke River that was capable of simulating daily flow releases and modeling the relationship between river flow and floodplain inundation. The Corps, Dominion and the State of North Carolina joined to support model development.

For several years, the processes of modeling, monitoring and adaptive management on the Roanoke moved forward. Meanwhile, monitoring under the settlement agreement for Dominion’s dams continued, as did a formal study by the Corps, under Section 216 of the Federal Flood Control Act, to assess management alternatives of the Corps-operated Kerr dam and hydro project.

Finally, in 2016, both processes reached their formal conclusion. The final settlement agreement was reached with Dominion and it included limits on peaking from the two facilities to reduce its contribution to the extended duration of flooding during the trees’ growing season.

The Corps’ 216 Study resolved with a revision to the Water Control Plan, with the primary change to operations known as the “quasi-run-of-river” (QRR) operation, meaning management of floodwaters being released from Kerr Dam will become closer to the dynamics of natural floods.

In addition to the environmental benefits, Corps Water Management Chief for the Wilmington District Tony Young said the change in water management will also benefit flood control.

Under the previous management plan, water was held in the flood pool of Kerr Reservoir for long periods, diminishing capacity to manage additional storm events. When a big storm came along, it filled up rapidly and water was released quickly.

As for hydropower production, it remains the same at the Kerr and Gaston powerhouses because the QRR operation still puts all the water through the turbines. The only loss occurs at Roanoke Rapids, where a portion has to pass through the flood gates. It’s estimated at a 3% loss system-wide in average annual generating capacity to realize these broader environmental and flood control benefits, and economic return is anticipated as well.

A recent study by Dr. Chris Dumas at the University of North Carolina-Wilmington predicted changes in flows under QRR will generate an additional $525,000 per year in sales and services related to recreation and a net national economic benefit of $2.4 million per year in aggregate recreation value at Kerr Lake.

The Roanoke River serves as a demonstration site for the Sustainable Rivers Program, which is is a partnership between the Corps and the Conservancy established in 2002. Now impacting more than 20 rivers, the program involves the reoperation of dams guided by state-of-the-art research to produce mulitiple benefits for people and nature. Its aim is to improve conditions on 2,000 river miles.

The next generation of hydropower

The story of the Roanoke River, and much of the Conservancy’s historic work at the project level, demonstrates ways to revisit current infrastructure to benefit river systems. But the Conservancy realized early on that a number of major impacts cannot be mitigated effectively at the scale of a single dam, and project-level sustainability cannot address the complex issues posed by multiple developments across a river basin or region. To achieve a more sustainable future, it’s critical that we look to the next generation of hydropower. We must get ahead of the game in places around the world where development is in the planning phase and provide tools that enable more strategic, low-impact and cost-effective options up front to better protect river systems.

Such an approach — what the Conservancy calls Hydropower by Design — can produce economic benefits for countries. Key findings from the Conservancy’s 2017 report, The Power of Rivers: A Business Case, suggest that the potential global economic benefits of widespread adoption of system-scale planning are significant. Even a 5% improvement in other water-management resources in hydropower-influenced basins would produce up to $38 billion per year in additional benefits, a sum comparable to the global average annual investment in hydropower.

Another financial value for investors lies in improved risk management. Hydropower by Design can guide site selection toward a portfolio of projects with a lower percentage of significant delays and cost overruns due to environmental and social risks. Recent work in Colombia’s Magdalena River basin demonstrates what is possible.

Spanning nearly a quarter of the country’s land area and housing three-quarters of its population, the Magdalena River basin is, in many ways, the social, cultural and economic heart of Colombia. The basin is responsible for 75% of Colombia’s agricultural production and 86% of its gross domestic product and is home to thousands of animal species, including more than a hundred fish species that are endemic to the region.

The Magdalena basin also generates 70% of Colombia’s hydropower, with 35 dams currently operating and roughly 100 sites for potential new hydropower projects identified. To Colombia, these new projects represent an important source of low-carbon energy for its growing population.

However, decisions about where new dams are developed and how they are operated could have high ecological and social costs. An early, system-scale approach such as Hydropower by Design could help mitigate impacts and reduce risks for investors.

Imagine what the Roanoke River Basin in the U.S. would have looked like if the function of its floodplain and river flows could have been better maintained through early-stage planning like this. The opportunity to consider river system-scale needs at the onset of a project can have profound long-term benefits for people, nature and the bottom line. To this end, the Conservancy and its partners launched the Decision Support System for the Magdalena-Cauca basin (known as SIMA) in March 2017 in Bogota.

SIMA is an open-access scientific tool that models the trade-offs for tough development and conservation decisions in the river basin. Using the tool, authorities and developers can visualize at an early stage of development what the cumulative impact of each of their projects will be on the basin. SIMA not only provides an early warning but also helps identify solutions and guides water infrastructure investments to the conservation of key ecosystems vital for water regulation, such as wetlands and savannas. 

Alejandro Santo Domingo from Fundacion Mario Santo Domingo — a nonprofit organization dedicated to promoting the common good and social development of the Colombian people — indicated “SIMA will support responsible decision making towards achieving development and ecosystem conservation goals that are strategic for this watershed. This would benefit all Colombians, now and into the future.”

The launch of SIMA follows nearly 10 years of the Conservancy’s multi-sector collaboration on integrated river basin management in Colombia and signing of a memorandum of understanding in December 2016 with the Colombian Ministry of Environment. The MoU outlines how the Conservancy and public and private partners in Colombia — such as the Colombian Ministry of Environment, national environmental licensing agency, power generators association and others — will begin a historic, collaborative partnership for transparent system-scale decision-making in the Magdalena Basin.

A similar approach to Hydropower by Design is building in Gabon. More than 80% of the Central-African country is covered in rainforest — from its remote interior to its Atlantic beaches, where elephants and gorillas emerge from the treeline and hippos surf the shore.

Gabon is committed to continuing the growth of its economy while protecting this natural capital, which is a vision etched in its strategic development plan.

The Gabonese government hopes it can reduce dependency on fossil fuels, a resource that has been the country’s economic driver for the past five decades. With a hydropower potential estimated at more than 9,000 MW for a country half the size of France, Gabon’s environment is at risk if planning future energy production isn’t done at the system scale.

Gabon’s National Master Plan for Electricity analyzes options for new projects throughout the country and presents different scenarios to favor profitability, satisfy the growing national demand for energy, and develop export potential to the Central-African sub-region.

“We need to complement this master plan with consideration of potential environmental and social impacts of the different options and scenarios presented,” said Aristide Ngari, Director General of Energy for the Gabonese government.

With the Conservancy’s support, Ministry officials recently developed terms of reference for a strategic environmental assessment (SEA) of the hydropower sector on the national level. The SEA is the first step in developing a comprehensive national energy master plan that incorporates environmental and social criteria, in addition to traditional engineering and financial considerations.

The Conservancy learned on the Roanoke River that while we can mitigate ecosystem decline after development, the best way to maintain balance is to avoid major impacts from the start. To this end, the Conservancy has also been active on the ground in Gabon, bringing together Gabonese and American scientists to sample fish species in rivers where flows may soon be impacted by new development. The results of their findings will be shared with government authorities to consider as part of their planning.

“We’re creating the baselines,” says Jean-Herve Mve Beh from Gabon’s National Research Center, who co-leads the exploration.

With a better grasp of this and collaboration across sectors, we can make more informed decisions and set people and nature on a course to thrive together. Hydropower by Design is a compelling approach as it can be integrated into a wide range of planning, regulatory, risk-screening and other management and decision-making processes. It’s a way to realize broader financial gains as well as reduce risks, cost overruns and implementation delays due to environmental and social impacts — all of which could undermine hydropower’s potential to contribute to a renewable energy future. Hydropower by Design helps reduce risk and identify development and management options that are both strategic and low-impact as well as financially competitive.

For more information on Hydropower by Design and how you can apply it, visit nature.org/powerofrivers and download The Power of Rivers: A Business Case. You can also reach out via the contact information at bottom of the webpage.

Michelle Lakly is The Nature Conservancy’s Managing Director for Saving Great Rivers; Chuck Peoples is the Conservancy’s Director of Conservation Programs, North Carolina Chapter; Jorge Gastelumendi is the Conservancy’s Director of Global Water Policy; and Marie-Claire Paiz is the Conservancy’s Gabon Program Director.

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