Before it went belly up, the automotive brand Oldsmobile ran a series of TV ads saying, "This is not your father’s Oldsmobile," trying to shake off the stodgy image that the brand had come to represent.

Hydropower is a bit like that — unexciting compared to the new kids on the block, solar and wind. It's a centuries-old technology, associated with massive government projects of almost unimaginable scale. It’s also controversial due to some of its adverse impacts caused by the flooding of large tracts of land in order to make large scale hydropower possible. A number of international projects have generated significant pushback from the environmental community, and here in the U.S., a considerable number of dams have been demolished after having been determined to do more harm than good, which leads to the question, "How sustainable is hydropower, really?"

That question has been carefully considered by the Hydropower Sustainability Assessment Protocol, "a reference framework that enables the development of a full sustainability profile of a hydropower project …evaluating the sustainability of a project against more than 20 social, environmental, technical and economic topics."

The protocol is used to assess projects based on topics ranging from governance, to siting and design, to hydrological resources, water quality, affected communities and public health.

While all energy sources have some undesirable impacts, and hydropower is no exception, it does have the advantage of being both carbon-free and, in most cases, continuously available.

The International Hydropower Association (IHA) is a not-for-profit, international organization with members active in more than 100 countries, working to advance sustainable hydropower.

It recently released a new book, "Better Hydro: Compendium of Case Studies 2017," at the 2017 World Hydropower Conference in Addis Ababa.

According to the editors, the collection of 34 case studies "casts light on innovative local and regional approaches to the preparation, implementation and operation of selected hydropower projects from across the globe. These can be considered as going beyond basic good practice as defined in the Hydropower Sustainability Assessment Protocol and which demonstrate a clear contribution to sustainable practice in the hydropower sector."

While all energy sources have some undesirable impacts, and hydropower is no exception, it does have the advantage of being both carbon-free and (mostly) continuously available.

Topics in the case studies, and their respective lessons learned, fall into categories as diverse as: asset reliability and efficiency; biodiversity and invasive species; cultural heritage; downstream flow regimes; economic viability; indigenous peoples; environmental and social issues; and downstream flow regimes.

For example, in the case of the Kabeli-A project in Nepal, the river itself is considered sacred by people in the region. Anthropologists were called in to assess all potential impacts, along with extensive community discussion. As a result, accommodations were made in the operating plan to ensure that cultural concerns — such as maintaining a minimum flow rate at certain times of year — were met.

The Keeyask project on the lower Nelson River in Manitoba was developed in partnership with four Cree Nations peoples. Engagement with the indigenous residents extended to a 25 percent ownership stake in the project. The Keeyask Cree Nations were heavily involved in the project planning and conducted their own environmental impact assessment incorporating both their local knowledge and their worldview.

The Chaglla project, on the Huallaga River in Peru, was an example of thorough environmental and social risk assessment. A highly engaged stakeholder process resulted in assessments on "fish and ecology, water quality modeling, downstream flow modeling, a resettlement action plan, and analysis of the project’s carbon footprint." Additional outcomes included the establishment of a new social services and agricultural services extension center, 800 local people trained to work on the project, a recycling center set up, the discovery of several new species and the establishment of an "important bird area" in the region which will help protect the biodiverse forest.

Mankind has flourished, largely due to our ability to harness far more energy than we are physically able to generate. Most if not all of these efforts have had unintended consequences. But, as this study shows, those consequences can be minimized and managed if they are undertaken using the best processes and skills available, drawing from disciplines as diverse as all a college catalog contains, along with a deep and abiding respect for all stakeholders including the planet itself.