Before revision: In its published final report, the WCD concluded that although "dams have made an important and significant contribution to human development, and benefits derived from them have been considerable ... in too many cases an unacceptable and often unnecessary price has been paid to secure those benefits, especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers and by the natural environment.
After revision: In its published final report, the WCD concluded that although "dams have made an important and significant contribution to human development, and benefits derived from them have been considerable in too many cases an unacceptable and often unnecessary price has been paid to secure those benefits, especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers and by the natural environment.