Introduction

Although proposals for large dams and canals have recently aroused intense oppositionoften for good reason-we will need more dams soon; therefore we need to learn better methods of design and operation. Despite the growing and increasingly vocal opposition to these water projects, our increasing populations and rising water-consumption rates make more dams inevitable. In Africa and other drought-prone regions of the globe, we still need dams big enough to store the biblical 7 year supply (Figure 1.1). We can and must learn to build these structures in ways which will not harm their regional ecology.