This rare and comprehensive view, published in 1965 by the Irrigation Districts Association of California, shows the entire state’s hydrological infrastructure as it developed following the Second World War. This particular map was first issued in 1949 and subsequently revised four times (1951, 1958, 1961, 1963) before the current state was issued. The map was designed as an educational tool that gave viewers “a comprehensive picture of water resources development in California.”
Looking northeast from the Pacific, we are treated to a full view of the state, stretching from Crescent City and the Oregon border in the north to San Diego and the Imperial Dam on the frontier with Mexico. The purpose of the poster is informative, showing the state’s technically complex and extensive water-bearing infrastructure. The landscape and its topography are depicted in relief and held in vibrant green, whereas all the waterways and associated features contrast this in a sharp blue.
The poster map is filled with details. Many of these are topographical landscape features – the San Joaquim River Valley or the peaks of Mt Lassen and Mt Shasta stand out clearly, but most of the detail pertains to the existing water infrastructure. Despite covering a vast area, the level of detail means that even the more obscure or diminutive elements of the system are displayed, labeled, and often explained. Larger features such as dams, reservoirs, lakes, rivers, and aqueducts are all drawn in prominently and labeled accordingly. Cities, too, are labeled but only shown as hatched areas. The purpose here is to display regional infrastructure.
There are multiple text boxes, many of which include substantial explanatory texts. In the upper left corner, five columns cover a variety of subjects, including ‘Water in California,’ ‘U.S. Army Corps of Engineers Flood Control Dams,’ U.S. Bureau of Reclamation, ‘Municipalities, ‘ and ‘District Water Development Distribution.’ There is also a short section entitled ‘About the Map,’ which explains the history of the map from its first state in 1949 to the current 1965 edition. This section of text also makes it clear that the “[..] map is a topographical effort to show major water development systems and their general relationship to the geographic features of the State.”
In the lower right corner is a second large text box describing the ‘State Program’ as it pertains to water management in California. Smaller text boxes related to specific sites and areas are also found throughout the map – especially around the Colorado River complex. It is clear from the subject matter of the various texts that this poster constitutes an official document meant to instill a basic understanding of California’s hydrology. As such, it includes both planned/proposed features and features under construction or already finished. These are shown on the map as white and black dots, respectively.
Ultimately, this is a cartographic compilation of a comprehensive and highly technical system of infrastructure that is deeply connected to the natural landscape. Nevertheless, its palpable aesthetic qualities also make this map a vibrant piece of visual culture.