Tag Archive for 'Central Valley'

Evaporation from California Irrigation Adds Enough Water to Colorado River to Supply 3 Million People

Published on 02/01/2013 in agriculture, hydrology and rivers. 0 Comments Tags: , , , , , .

California Central Valley Project delta irrigation colorado river water supply

Retrieved from: Circle of blue

“California’s Central Valley is an agricultural machine. The valley, which accounts for one-sixth of irrigated lands in the United States, produced crops worth $US 21 billion in 2007, according to the most recent U.S. Census of Agriculture, a comprehensive analysis of U.S. agricultural production.

“Irrigation in the Central Valley also generates an important, less visible export: water vapor. Through evaporation, that water vapor, once aloft, is a significant source of summer precipitation and streamflow hundreds of kilometers away in one of the nation’s most water-scarce river basins, adding enough water each year to the Colorado River to cover the daily needs of 3 million people, according to startling and intriguing climate-modeling research from scientists at the University of California, Irvine, and National Taiwan University.

“The study sheds light on a vital but poorly understood component of the water cycle, providing a first estimate for how irrigation in one region can still affect the water balance of a distant, geographically disconnected river system. According to the study, evaporation from Central Valley irrigation increases the summer flow of the Colorado River by 28 percent — or 400 million cubic meters (325,000 acre-feet) — compared to having no irrigation at all. In the Four Corners region, the effect is even more pronounced, increasing summer flows by 56 percent.”

Read more: Circle of Blue

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Central Valley towns on high alert over large runoff

Published on 05/19/2011 in contaminated water, floods and hydrology. 0 Comments Tags: , , , , , .

Retrieved from: ABC local

“California could face a serious flooding threat this spring, if the snow in the Sierra begins to melt all at once. In fact, some towns in the Central Valley have already been placed on alert

“This past winter will be remembered for near record snowfall in the high Sierra. While the huge snowpack is a bounty for California’s water situation, it could also create big problems for those downstream.

“The main area of concern is in the San Joaquin River Valley,” said Dave Rizzardo, the chief of California’s snow surveys.

“With that much snow sitting in the central and southern Sierra and those reservoirs are already full, they’re going to have a major juggling act between now and June to pass that flow through the reservoirs and down into the river and into the valley without inundating the system,” said Rizzardo.

“Already major rivers are running high, especially in the San Joaquin Valley where the waterways are much narrower than those to the north in the Sacramento Valley. So far, state managers have released water gradually from bloated reservoirs like Melones and Don Pedro, but if the weather gets too warm, too soon, things could change in a hurry.

“If it gets really hot, undoubtedly the flows will come down in a way that will create flood issues,” said Joseph Countryman from MBK Engineers.

“Countryman is the former chief of flood operations for the Army Corps of Engineers.

“We have a snowpack now that’s going to provide more water than we can deal with. It’s going to fill all the reservoirs. We’re not going to have any reservoirs that are going to have any empty space in them,” said Countryman.”

Read more: ABC local

sammykayed

California farmers, ecologists square off over drinking water pollution

Published on 04/09/2011 in agriculture, contaminated water, groundwater and management. 0 Comments Tags: , , , , , , , .

Retrieved from: LAtimes

“Should farmers in the Central Valley, California’s richest agricultural region, be required to monitor and clean up groundwater pollution from their operations? The issue will be taken up by the Central Valley Regional Water Control Board at a three-day meeting in Rancho Cordova beginning June 8.

“Under the proposed regulations, farmland would be classified based on the contamination risk. Farms considered most likely to pollute groundwater would have to take certain steps to reduce fertilizer and other agricultural runoff. If passed, the new rules would affect 35,000 growers who work about 7 million acres of irrigated land.

“Environmentalists faced off against farm groups in an all-day public hearing Thursday in Rancho Cordova. Farmers said that the regulations would be expensive and burdensome.  Environmental and community groups said that current rules don’t protect drinking water from pesticides, fertilizers and other agricultural runoff.

“Runoff from irrigated agriculture is the largest source of pollution to Central Valley waterways and the Delta,” said the Sierra Club, the Center for Biological Diversity, the California Sportfishing Protection Alliance and more than 70 other state and local groups in a joint statement. “This pollution is one of the principal causes of the collapse of Central Valley fisheries.

“Inexplicably, irrigated agriculture remains exempt from requirements to monitor discharges and identify measure to reduce pollution,” the groups said, adding that such rules have “long been applicable to every other segment of society, from municipalities to industry to mom and pop businesses.”

Read more: LAtimes

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