Historical Ecology and Landscape Change in the Central Laguna de Santa Rosa

San Francisco Estuary Institute (SFEI) | March 1st, 2017

This study synthesizes a diverse array of data to examine the ecological patterns, ecosystem functions, and hydrology that characterized a central portion of the Laguna d

This study synthesizes a diverse array of data to examine the ecological patterns, ecosystem functions, and hydrology that characterized a central portion of the Laguna de Santa Rosa during the mid-19th century, and to analyze landscape changes over the past 150 years. The primary purpose of this study was to help guide restoration actions and other measures aimed at reducing nutrient loads within this portion of the Laguna de Santa Rosa watershed.

Historical Seawater Intrusion Map Pressure 180-Foot Aquifer - 500 mg/L or Greater Chloride Areas

Monterey County Water Resources Agency (MCWRA) | April 11th, 2018

History of Legislation and Policy Formation of the Central Valley Project

U.S. Department of Agriculture (USDA) | March 15th, 1946

History of the All-American Canal: Boulder Canyon Project

U.S. Bureau of Reclamation (USBR) | December 1st, 2009

A narrative history of the construction of the All American Canal, Imperial Dam, and the Coachella Canal.

A narrative history of the construction of the All American Canal, Imperial Dam, and the Coachella Canal.

History of the Delta Division, Central Valley Project

U.S. Bureau of Reclamation (USBR) | October 1st, 1994

The Delta Division of the Central Valley Project (CVP) acts as the hub around which the CVP revolves. The Delta Division contains the facilities that transfer water from

The Delta Division of the Central Valley Project (CVP) acts as the hub around which the CVP revolves. The Delta Division contains the facilities that transfer water from the Sacramento River, to bolster irrigation supplies to thirsty lands formerly dependent on water from the San Joaquin River. In time, the Delta Division became the hub for controversy revolving around the Central Valley Project. This document recounts the history of the Delta Division.  It was produced by the Bureau of Reclamation.

History of Water Project Conveyance in the Delta

California Natural Resources Agency (CNRA) | January 6th, 2016

A fact sheet on the history of conveyance in  the Delta; includes a timeline from the 1950s to present.  Prepared by the Department of Water Resources.

A fact sheet on the history of conveyance in  the Delta; includes a timeline from the 1950s to present.  Prepared by the Department of Water Resources.

Holocene paleoclimate records from a large California estuarine system and its watershed region: linking watershed climate and bay conditions

Quaternary Science Reviews (Elsevier) | July 10th, 2006

The San Francisco Bay-Delta system includes a watershed that covers a large area of California and provides water to two-thirds of the State's population. Climate

The San Francisco Bay-Delta system includes a watershed that covers a large area of California and provides water to two-thirds of the State's population. Climate over the estuary and its watershed in the dry summer months is controlled by the subtropical high which dominates and deflects storms from California. The subtropical high weakens and migrates south as the Aleutian Low strengthens, bringing wet winter storms to the region. Paleoclimatic records from the Bay and its greater watershed, spanning the Holocene, are reviewed here in order to better understand natural variations of precipitation and runoff and the linkages between those variations and the salinity and ecosystems of the estuary. To better understand regional-scale climate patterns, paleoclimate records from coastal California and the Great Basin are also considered. Large fluctuations in climate have occurred during the period of interest, and there is generally good agreement between the paleoclimate records from different regions. Early Holocene climate throughout California was marked by rising temperatures and reduced moisture as seen in fire records from the watershed. This warmth and aridity peaked about 5000–7000 years ago and was followed by a cooling trend, with variable moisture conditions. The Estuary formed relatively rapidly in response to a high rate of sea level rise that dominated the Holocene until about 6000 years ago, and the subsequent reduced rate of inundation allowed vast tidal marshes to form along the edges of the estuary, which have since been recording changes in environmental conditions. The impacts of changing regional climate patterns are experienced in the San Francisco Bay-Delta system, as altered fresh water flows result in altered estuary salinity. For example, approximately 3800 cal yr B.P., records from throughout the state indicate a cool, moist period, and Bay salinity was reduced; this period was followed by a general drying trend throughout California over the last two millennia, punctuated by decades to centuries-long droughts and brief, extremely wet events. In particular, during the period ca. 1000–800 cal yr B.P. (A.D. 950–1150) conditions seem to have been unusually dry in many parts of the watershed, reducing the fresh water flows to the estuary, and shifting tidal marsh plant assemblages toward less diverse, but more salt-tolerant plants. In contrast, the Little Ice Age (ca. 550–200 cal yr B.P.) brought unusually cool and wet conditions to much of the watershed, and lowered salinity in the Bay. Many reconstructions suggest that notably stable conditions have prevailed over the instrumental period, i.e., after ca. A.D. 1850, even including the severe, short-term anomalies experienced during this period. Interdecadal variability is common in many of the records, with timescales of ca. 55, 70, 90, 100, 150, and 200 years.

How Native Americans will Shape the Future of Water in the West

New Yorker | January 27th, 2023

As a child, Stephen Lewis heard stories about a river that, for the most part, no longer flowed. “How I grew up was that it was a theft, that it was stolen from us,”

As a child, Stephen Lewis heard stories about a river that, for the most part, no longer flowed. “How I grew up was that it was a theft, that it was stolen from us,” he told me late last year. “There was what we used to call the Mighty Gila River, and now it was just pretty much dry. There was no water.” Lewis is the governor of the Gila River Indian Community (gric), a group that has occupied land south of Phoenix for centuries. When I met him, in the dining room of the Whirlwind Golf Club, which the tribe owns, Lewis had recently returned from Santa Fe. There, he’d attended a celebration marking the centennial of the Colorado River Compact, an agreement that continues to shape water politics in the Southwest. In Santa Fe, Lewis took note of a black-and-white photograph of the compact’s signers—white men in dark jackets, gathered around a wooden desk.

How unusual is the 2012–2014 California drought?

American Geophysical Union (AGU) | December 30th, 2014

For the past three years (2012–2014), California has experienced the most severe drought conditions in its last century. But how unusual is this event? Here we use two

For the past three years (2012–2014), California has experienced the most severe drought conditions in its last century. But how unusual is this event? Here we use two paleoclimate reconstructions of drought and precipitation for Central and Southern California to place this current event in the context of the last millennium. We demonstrate that while 3 year periods of persistent below-average soil moisture are not uncommon, the current event is the most severe drought in the last 1200 years, with single year (2014) and accumulated moisture deficits worse than any previous continuous span of dry years. Tree ring chronologies extended through the 2014 growing season reveal that precipitation during the drought has been anomalously low but not outside the range of natural variability. The current California drought is exceptionally severe in the context of at least the last millennium and is driven by reduced though not unprecedented precipitation and record high temperatures.

Hydro-Electric Development in California

Scientific American | August 2nd, 1913

A glance at a map of California similar to that accompanying this article, on which is portrayed the veritable network of long-distance transmission lines that mark th

A glance at a map of California similar to that accompanying this article, on which is portrayed the veritable network of long-distance transmission lines that mark the course of hydro-electric development from end to end of the State, might convey to one not acquainted with actual conditions, the impression that there is but little left undeveloped of the sources of water-power with which this wonderland of the West abounded when first adventurous man started out in his now far-reaching enterprise among the head-waters of our mountain streams. This impression has, indeed, been circulated widely by those who in pursuit of a. policy of so-called conservation would hinder the development of California/s natural resources, and so, her progress and advancement. What foundation it has in fact may be gathered from certain statistics to hand. Mr. M.O. Leighton, Chief Hydrographer of the United States Geological Survey at Washington, in an article on “Water-power in the United States," published in the May number, 1909, of the Annals of the American Academy of Political and Social Science, writes: “The “water power plants in the United States make productive use of only 5,500,000 horse-power, less than one fortieth of that ultimately available.” The report of the United States Geological Survey upon California, published March, 1912, gives the following figures for our State: Potential horse-power development on a basis of 90 per cent efiiciency; minimum 4,109,000, estimated maximum 9,382,000; on a basis of 75 per cent efficiency, minimum 3,424,000, estimated maximum 7,818,000.