1.   So to Indian planners, the Tehri dam makes doubly good sense.

2.   The dams make Lewiston, Idaho, a seaport and offer cheap transportation from a scattering of grain elevators that hug reservoirs from Lewiston to the Tri-Cities.

3.   The dam makes money by providing power at times of peak electricity demand, when the price is higher than it is the rest of the day.

4.   A dam made from discarded tires tests a new way to stop rainy-season erosion.