Upstream they’ve allowed the water level of the river to fall until the dam’s top blocks can be seen as the waterfall retreats. The river’s bottom emerges and a spring shorebird skitters along the edge of the green muck, its beak probing the dirt. Three pigeons pace on and peck at the drying granite blocks. Each block in the slightly curved dam wall under their feet is an easy ton of stone. The dam spans the river and, when the water is allowed to rise, it vanishes under a sheen of falling water. But now the water is low even though the river still flows.
Behind the dam a grating of steel bars lets the river flow under the dam and gush out the spill pipe at the foot of the stone blocks. There the river continues to flow under the footbridge, between the stone and brick walls of the mill, over another waterfall further on, and then, past other mills still downstream, out to sea.