This map shows streamflow measured in acre-feet (1 acre-foot Is the amount of water that would cover an area of one acre to a depth of one foot – 43,560 cubic feet or about 326,700 gallons). Streamflow is measured and recorded by the U.S. Geological Survey at gaging stations located at the centers of the blue circles shown on the map. Average annual streamflow is shown by the size of the circles and by numbers indicating acre-feet. Distribution of flow for months of the year is shown by histograms; at most stations, flow is greatest in May and June because of runoff from melting snowing the high country in the western part of the quadrangle. Bars from left to right in the histograms run from October of one calendar year to September of the following year (water year). Years from 1940 to 1970 for which measurements were taken and for which streamflow is calculated are indicated under the histograms. Note that scales at the left side of the histograms, which indicate acre-feet per month, are different for different gaging stations.
