This book is about the Zambezi River and the flora, fauna and people who depend upon its waters. The Zambezi is the smallest of Africa's great river systems, but its catchment area spans East, Central and Southern Africa. The people of Zambia, Democratic Republic of Congo, Angola, Zimbabwe and Mozambique share its waters and are both connected and separated by them. Outsiders approached it as a point of entry to the region, but its many cataracts, most spectacularly Victoria Falls, frustrated navigation. Today, the river's flow is further interrupted by large hydroelectric dams: the Kariba on the border of Zambia and Zimbabwe, built by the British in the late 1950s, and Cahora Bassa in Central Mozambique, initiated a decade later by Portugal with an international consortium. Cahora Bassa was put into operation just months before Mozambique became independent under the Front for the Liberation of Mozambique (today Frelimo) in 1975. Portugal retained ownership of the dam through the parastatal corporation HCB (Cahora Bassa Hydroelectric) until November 2007 when Mozambique finally purchased 85 per cent of HCB shares.

It is not surprising that this ambitious, detailed and broadly researched book won both the African Studies Association's 2014 Melville J. Herskovits Award and the American Historical Association's 2014 Martin A. Klein Prize in African History. Allen and Barbara Isaacman focus on the construction, output and impact of the Cahora Bassa hydroelectric dam between 1965 and 2007. They explore the arrogance embedded in ideas such as development and modernization, and probe the power landscape among Portuguese, South African and Mozambican actors around the production and consumption of the dam's hydroelectric power. They argue that, whether under the control of the Portuguese or Frelimo, the Cahora Bassa dam has ‘impoverished’ the people it displaced and ‘devastated’ the environments it transformed both up- and downstream.

Chapter 1 states the authors’ intention to write an ‘alternative history’ by recovering through oral testimony what ‘the colonial and postcolonial state actors have suppressed’, and claims that, unless development projects serve ‘human and environmental well-being’, they are merely a delusion (p. 7). It reviews the literature on Africa's dams, large dams globally, development-induced displacement of people, animals, plants and soils, and the challenges of history and memory (pp. 7–28). Chapter 2 provides a concise overview of the ‘Zambezi River valley in Mozambican history’, with helpful maps, charts, tables and photographs. The ‘Lower Zambezi ecosystem’ (pp. 40–56) introduces agriculture and fishing, and the exploitation of wildlife and forest resources as practised in the region. It pays admirable attention to gender and family dynamics. Chapter 3 approaches Cahora Bassa as a study in high modernism, demonstrating Portugal's awareness of the project's contradictions and unsubstantiated assumptions from the outset. The wrenching labour history of the dam's construction is drawn from scores of oral narratives, while the photographs aptly illustrate the scale and danger of working underground among massive boulders or atop the structure's precipices. Attacks on this strategic target ceased only in 1992. Chapter 4, also carefully rooted in testimony, provides a detailed portrait of what those displaced by the dam and reservoir faced: ‘We arrived here and began to die’ (p. 114). The ironies of the transformation of Portuguese wartime strategic villages into Frelimo communal villages and back to strategic villages during the Renamo insurgency are painful. Chapter 5 documents the transformation of the earlier described Lower Zambezi ecosystems, from the desiccation of floodplains to the salinization of soils. Chapter 6 concludes that: ‘Rather than promoting national economic development or sustainable livelihoods for the people living adjacent to the river, the dam has instead robbed Mozambique of precious energy’ (p. 150). The final chapter, ‘Legacies’, summarizes the book's findings and raises further concerns about plans for a new hydropower dam to be built downstream from Cahora Bassa at Mphanda Nkuwa that would exacerbate all the problems they delineated for Cahora Bassa. Although Mozambican and international environmental justice and anti-dam groups have lobbied against Mphanda Nkuwa, people who live in the region, like those displaced by Cahora Bassa, feel powerless to protest, anticipating that they will simply be forced to comply with a state ‘order’ (p. 182).

The Isaacmans draw on multiple literatures across many disciplines to make their compelling points, but perhaps their key contribution is the extensive collection of oral narratives that they then use to interrogate materials from the archives and press. Engaging the scientific literature on hydropower and environmental change, they challenge the assumptions and practices that shaped the dam's construction and produce a withering critique of the ‘modernist’ arguments. Regarding social displacement through development, they draw on and enhance the important gendered insights of anthropologist Elizabeth Colson, who worked in the 1950s with people displaced by Kariba.

This impassioned account is dedicated to ‘the people of the lower Zambezi valley’ (p. v), and follows pathways forged in Zambezia by the Isaacmans for more than four decades. Whether working as individuals, as a team, or in collaboration with others, the hallmarks of their work are political commitment and a focus on ordinary people. They are unapologetic scholar activists. Allen Isaacman titled his presidential address to the African Studies Association (USA) ‘Legacies of engagement: scholarship informed by political commitment’.

Cahora Bassa's energy potential has not developed Mozambique's economy. The Isaacmans accuse Frelimo of ‘shortsighted and destructive policies that continue to overwhelm and silence the pressing concerns of rural communities in the valley’ (p. 167). Mozambicans had to absorb the costs of destruction and terror wrought by South Africa-backed Renamo fighters, yet South Africa has neither paid reparations nor relinquished its privileged position regarding power distribution (p. 151). Rather, South Africa has consumed most of Cahora Bassa's power at discounted prices, a fact that the Isaacmans argue reveals that post-apartheid South Africa continues to pursue its own interests at the expense of its neighbours.