[Five Large Blueprints of Early Depression-Era Weber Dam Modifications]

Placerville, Ca, 1929. Very good.. Five blueprints, measuring from approximately 24 x 34 to 29 x 41 inches. Tipped onto modern cardboard backing at left edge, overlaid with brown paper. Light wear, a couple of archival repairs at edges. Contemporary blind stamps. A group five large and fascinating blueprints that delineate proposed modifications to the Weber Dam near Placerville, California, that were carried out in 1930. The Dam was originally built in 1922 and 1923 without steel reinforcement, and as a result improvements have been required periodically from its completion up to the present day. The designs present here outline the first set of such improvements, overseen by an engineer named George W. Hawley in 1929 and 1930. These include the construction of new tunnels, outlets, gates, and spillways, and also include detailed topographical charts of the area surrounding the dam. The blueprints, which were intended to accompany an engineer's report on the project, are as follows:

1) Contour Map Showing Plan & Section of Dam, and Location of Supply Tunnel & Wasteway.
2) Outlet Structures Showing Tunnel and Shaft Control Works & Appurtenances.
3) Details of Spillway.
4) Details of Tunnel Valves & Controls.
5) Contour Map of Borrow Area for Weber Creek Dam.

The dam and the reservoir that it created, managed by the El Dorado Irrigation District, provide vital power and water services to area agriculture. The present plans comprise an important document of the early upkeep and development of the structure.