Dams also have a range of social impacts (see Table 2). Most importantly, dams have compelled the relocation of millions of people. For example, it has been estimated that since the independence of India, about 14 million people have been displaced by dams and related construction, such as irrigation canals. Perhaps another 10 million people have been displaced in China. This, at least, is the government's own figure. Others have estimated that somewhere between 40 and 60 million Chinese have been relocated.

In the great majority of cases, the economic well-being and health of those affected have declined after being relocated. Existing communities have been uprooted, often dispersed, causing people to lose their social support networks, as well as their livelihoods and ways of life. For example, when the World Bank looked at projects that it had helped
fund, and that involved involuntary resettlement, it found that out of 192 projects examined, the number of projects in which all of those resettled benefited from the project was exactly zero.

Loss of community control over water: Dams, as a large-scale, highly sophisticated technology, typically demand much technical expertise for their operation. This demand for expertise most often results in their management being taken over by government or corporate bureaucracies. And as control over resources becomes more centralized, individuals and communities will tend to lose the control that they once had over the resources that they once depended on.

Dams can also have range of other human impacts. Various diseases have become more prevalent, as a direct consequence of dams and related projects. One example is schistosomiasis, which now affects about 200 million people. Malaria is also becoming increasingly prevalent, and now affects about 300 million people. Dams create excellent habitat for water-borne disease parasites responsible for these diseases, i.e. large areas of standing water created by dam reservoirs or irrigation projects in tropical countries, which provide a good habitat for the snails that spread schistosomiasis, and the mosquitos that spread malaria.

For a variety of reasons, the impacts of dams are often felt disproportionately by women. Compensation payments to those displaced by projects are most often made to men, converting the collective assets of families into disposable cash held by the men. Women are also often most dependent on the common resources that are eliminated by dam projects. They may also be particularly vulnerable to the social and cultural breakdown that commonly occurs within communities forced to relocate.