This involved impounding the headwaters of the Wye, the Towey and the Usk, and the total cost was estimated to exceed fifteen millions sterling.
Recognizing this, the corporation of Birmingham, under an act of 1892, acquired the watershed of the Elan and Claerwen, and constructed on the Elan three impounding reservoirs whence the water is conducted through an aqueduct to Birmingham (q.v.).
In all reservoirs impounding the natural flow of a stream, this involves the use of an overflow.
Perez says that the Sarare branch of the Apure has formed a gigantic dam across its own course by prodigious quantities of trees, brush, vines and roots, and thus, impounding its own waters, has cut a new channel to the southward across the lowlands and joined the Arauca, from which the Sarare may be reached in small craft and ascended to the vicinity of Pamplona.
After Becket's flight (1164), the king put himself still further in the wrong by impounding the revenues of Canterbury and banishing at one stroke a number of the archbishop's friends and connexions.
They are heat-filters or heat-traps for impounding the heat developed by the combustion of the furnace gas, and later returning it to the blast.
Near Douglas, in Converse county, there is a reinforced concrete dam, impounding the waters of Laprele Creek, to furnish water for over 30,000 acres, and power for transmitting electricity.
In the simplest case of a single mountain valley to be used for the supply of an impounding reservoir, the rainfall should be known at five points, three being in the axis of the valley, of which one is near the point of intersection of that axis with the boundary of the watershed.
Very generally, especially in the butte regions, the country lends itself to the impounding of surface water.
Show respectively the portion of the valley visible from the dam before impounding began, and the same portion as a lake on the completion of the work.