"Aurora and Colorado Springs are building a huge dam of rock on Homestake Creek southwest of Red Cliff. The dam will have an upstream impervious face of asphalt laid on a blanket of gravel atop the rock. There is a concrete curtain extending below the dam foundation into fock formations and into the mountainsides at both ends of the dam. The asphalt face is technically known as asphaltic concrete, the asphalt being binder instead of cement in what...