Identifier: cu31924004975805 (find matches)
Title: The future water supply of San Francisco; a report to the Honorable the secretary of the interior and the Advisory board of engineers of the United States army
Year: 1912 (1910s)
Authors: Spring Valley water company, San Francisco
Subjects: Water-supply
Publisher: (San Francisco, Printed by the Rincon publishing company
Contributing Library: Cornell University Library
Digitizing Sponsor: MSN

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
be sufficientas an average. There is also presented thecurious argument that when 214 acre feet peracre are applied annually upon the 206,000 acresin the districts 51,620 acre feet of water willhave to be pumped annually by the districts tokeep the ground water ten feet below the sur-face, this water to be used for further irriga-tion. No account seems to be taken of the re-quirements of plant life when the entire area isdeveloped and irrigated, as the argument seemsto be based upon the use during 1911 when ir-rigation was practiced on only one-half the area.If Mr. Freeman had cared to explain the exces-sive use and the present high water table in thedistricts he would have been to no great troubleto do so as he doubtless knows the very sandycharacter of the soil throughout a large part ofboth districts; that the ditches have been filled totheir capacit.^ since water was first turned intothem; and, furthermore, that the seepage lossesin these ditches have been and still are verylarge.
Text Appearing After Image:
276 IRRIGATION IN THE SAN JOAQUIN VALLEY AND THE BAY REGION 277 The annual rainfall is stated by the report tobe ten inches and the mean annual temperature63.9° No mention is made of other importantelimatologieal data, viz:—The summer tempera-ture is high, the air is dry, while the cold of win-ter is greater than in the bay regions. Untilirrigation was introduced this area was a sea ofwaving grain in the spring months and dry,parched stubble fields during the summer andfall. No attempt was ever made to raise summercrops, orchard trees or alfalfa on these sandyplains without having the necessary water forirrigation. Low Duty in the Niles Cone. In the Niles Cone with an almost uniformmean daily temperature throughout the year,with summer fogs, with a soil highly retentiveof moisture when tilled, and where crops of allkinds have been grown for many years solelyunder an average annual rainfall of 20 inches,or double that of the above mentioned districts,here it is suddenly discovered b

Note About Images