Friday, March 26, 2010

History of New York City's Water Supply System


Early Manhattan settlers obtained water Australia is one of the driest continents on earth. Water has been vital to the survival and prosperity of Sydney since the first days of the new colony. The need to ensure a reliable water supply through times of drought and erratic seasonal rainfalls has driven the development of several complex and innovative water supply schemes. for domestic purposes from shallow privately-owned wells. In 1677 the first public well was dug in front of the old fort at Bowling Green. In 1776, when the population reached approximately 22,000, a reservoir was constructed on the east side of Broadway between Pearl and White Streets. Water pumped from wells sunk near the Collect Pond, east of the reservoir, and from the pond itself, was distributed through hollow logs laid in the principal streets. In 1800 the Manhattan Company (now The Chase Manhattan Bank, N.A.) sank a well at Reade and Centre Streets, pumped water into reservoir on Chambers Street and distributed it through wooden mains to a portion of the community. In 1830 a tank for fire protection was constructed by the City at 13th Street and Broadway as was filled from a well. The water was distributed through 12-inch cast iron pipes. As the population of the City increased, the well water became polluted and supply was insufficient. The supply was supplemented by cisterns and water drawn from a few springs in upper Manhattan.

After exploring alternatives for increasing supply, the City decided to impound water from the Croton River, in what is now Westchester County, and to build an aqueduct to carry water from the Old Croton Reservoir to the City. This aqueduct, known today as the Old Croton Aqueduct, had a capacity of about 90 million gallons per day (mgd) and was placed in service in 1842. The distribution reservoirs were located in Manhattan at 42nd Street (discontinued in 1890) and in Central Park south of 86th Street (discontinued in 1925). New reservoirs were constructed to increase supply: Boyds Corner in 1873 and Middle Branch in 1878. In 1883 a commission was formed to build a second aqueduct from the Croton watershed as well as additional storage reservoirs. This aqueduct, known as the New Croton Aqueduct, was under construction from 1885 to 1893 and was placed in service in 1890, while still under construction. The present Water System was consolidated from the various water systems in communities now consisting of the Boroughs of Manhattan, the Bronx, Brooklyn, Queens and Staten Island.

Since 1842, there have been no significant interruptions of service other than brief annual shutdowns for the purpose of routine inspections during the period from 1842 to the Civil War.

In 1905 the Board of Water Supply was created by the State Legislature. After careful study, the City decided to develop the Catskill region as an additional water source. The Board of Water Supply proceeded to plan and construct facilities to impound the waters of the Esopus Creek, one of the four watersheds in the Catskills, and to deliver the water throughout the City. This project, to develop what is known as the Catskill System, included the Ashokan Reservoir and Catskill Aqueduct and was completed in 1915. It was subsequently turned over to the City's Department of Water Supply, Gas and Electricity for operation and maintenance. The remaining development of the Catskill System, involving the construction of the Schoharie Reservoir and Shandaken Tunnel, was completed in 1928.

In 1927 the Board of Water Supply submitted a plan to the Board of Estimate and Apportionment for the development of the upper portion of the Rondout watershed and tributaries of the Delaware River within the State of New York. This project was approved in 1928. Work was subsequently delayed by an action brought by the State of New Jersey in the Supreme Court of the United States to enjoin the City and State of New York from using the waters of any Delaware River tributary. In May 1931 the Supreme Court of the United States upheld the right of the City to augment its water supply from the headwaters of the Delaware River. Construction of the Delaware System was begun in March 1937. The Delaware System was placed in service in stages: The Delaware Aqueduct was completed in 1944, Rondout Reservoir in 1950, Neversink Reservoir in 1954, Pepacton Reservoir in 1955 and Cannonsville Reservoir in 1964.
The plan to develop a water supply system in the Shoalhaven first rose during the end of World War One. It was not until several decades later, in 1968, that the then Water Board consulted the Snowy Mountains Hydro-Electric Authority about the longer term water needs of Sydney and the south coast. There was concern that Warragamba Dam, which had opened only eight years earlier, might prove inadequate to meet Sydney's water supply needs by the mid 1970s.

The advice was to proceed with the Shoalhaven Scheme - situated in the lower Shoalhaven River and Kangaroo Valley areas - on the coastal range above Fitzroy Falls and on the Upper Wingecarribee River. Construction began in 1971 and was carried out by contractors under the supervision of the Snowy Mountains Engineering Corporation. The Scheme was completed in 1977 at a final cost of $128 million.

Water for the system is impounded in three upstate reservoir systems which include 19 reservoirs and three controlled lakes with a total storage capacity of approximately 580 billion gallons. The three water collection systems were designed and built with various interconnections to increase flexibility by permitting exchange of water from one to another. This feature mitigates localized droughts and takes advantage of excess water in any of the three watersheds.

In comparison to other public water systems, the Water System is both economical and flexible. Approximately 95% of the total water supply is delivered to the consumer by gravity. Only about 5% of the water is regularly pumped to maintain the desired pressure. As a result, operating costs are relatively insensitive to fluctuations in the cost of power. When drought conditions exist,The innovative Upper Nepean Scheme was Sydney's fourth source of water supply. Completed in 1888, the scheme diverted water from the Cataract, Cordeaux, Avon and Nepean rivers to Prospect Reservoir via 64 kilometres of tunnels, canals and aqueducts known collectively as the Upper Canal.

However, the Upper Nepean Scheme bought only temporary relief to Sydney's water supply woes. The drought of 1901-1902 brought Sydney periously close to a complete water famine. After two Royal Commissions into Sydney's water supply, the authorities agreed that a dam be built on Cataract River. The successive building of Cataract, Cordeaux, Avon and Nepean dams between 1907 and 1935 greatly improved the Upper Nepean Scheme's capacity
additional pumping is required.

Thursday, March 11, 2010

America’s Water Supply


-April 8, 2008


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I am amazed: since last summer, almost every day we see at least one news story on another water crisis in the U.S. The water crisis is no longer something that we know about as affecting developing countries or their poor in particular. It is right here in our own backyard. Today, in many parts of the U.S. we are nearing the limits of our water supplies. And that is getting our attention. The writing has been on the wall for some time. The private sector has been showing much interest in water as a source of profit, and water privatization has been an issue in many parts of the country.The failure in public water systems has indeed been a contributing factor for this interest. In many cities, consumers have been organizing and opposing the privatization of water utilities, because they have been concerned about affordability or deterioration in the quality of service. Environmental organizations and consumer activists have also been concerned about the socio-economic, health and environmental implications of ever increasing bottled water use. But for most of us living in the U.S., water is something we take for granted, available

-Groundwater resources, which provide half of the country’s drinking water as well as irrigation for crops and water for industrial use, also are diminishing, according to the U.S. Geological Survey’s (USGS) Groundwater Resources Program. The Ogallala Aquifer, the massive groundwater network that lies under the Great Plains and feeds water to more than a quarter of the region’s irrigated land, continues to be a significant concern.
“Basically the groundwater is being depleted of its resource,” said Kevin Dennehy, the USGS project coordinator. “It’s been happening for quite some time and it’s going to continue to happen. The removal of water from the aquifer is at a greater rate than water is being re-charged in the aquifer naturally.”

The deteriorating condition of the Ogallala is a case in point. According to a June USGS reportwater from the aquifer is generally acceptable for drinking, irrigation, and livestock. But irrigation and leakage of nutrients down inactive irrigation wells is increasing concentrations of contaminants including nitrates deep in the aquifer, posing long-term risks to its safety as a source of drinking water.

In a worst-case scenario, water levels for all five Great Lakes could fall by an average of one to two feet, with Lake Huron and Lake Michigan facing the sharpest declines. Such declines will affect beach and coastal ecosystems, expose toxic contaminants and hinder recreational boating and commercial shipping. This could be particularly troubling for Michigan, a state with more than a million recreational boaters and more shoreline than any other state but Alaska.
Melanie Fitzpatrick, a climate scientist with UCS’ Climate Program, said in an interview with Circle of Blue that her organization’s findings were based on two scenarios—one that predicts lower emission levels in coming decades and another that estimates higher emission levels.
“They depend on our population, they depend on our emissions choices and they depend on the kind of technology we might create,” she said.

The lower emission scenario is based on global adoption of emission limits like those in the American Clean Energy and Security Act of 2009 (ACES), which the U.S. House passed in June. ACES calls for reducing the nation’s carbon emission levels between 17 and 20 percent by 2020.
The higher emission scenario was meant to reflect a worst-case scenario, Dr. Fitzpatrick said. “Unfortunately, our emissions are currently tracking higher than that high-emission scenario,” she added.
Under either scenario, increasing temperatures could shift rainfall patterns across the Midwest—resulting in less rain in the summer, but more in the winter, spring and fall.

With heavy rains already twice as frequent as they were a century ago, the Midwest should brace for even heavier downpours in the coming decades and more frequent floods like those that inundated the region in 2008.
“We know that that’s already a problem,” Dr. Fitzpatrick said, “Spring flooding is a problem in agriculture in terms of farmers getting into their fields to sow their crops, and we’ve seen some really significant flooding.”
She cited the Red River in western Minnesota and eastern North Dakota as an example. In the spring of 1997, the river rose to record levels, killing 11 people, causing billions of dollars in damage, and forcing more than 60,000 people from their homes. While that flood was thought to be a once-in-a-hundred-years event at the time, similar floods followed in 2001, 2006 and 2009, with the river reaching its highest level in recorded history this spring in Fargo, North Dakota.
In Wisconsin last year, much of the state experienced its wettest June. Six inches of rain fell on the town of Ontario in a single day, and flash floods swept away homes, roads and bridges. In the popular resort town of Wisconsin Dells, water overtopped a highway separating Lake Delton from the Wisconsin River, creating a washout that drained the lake dry.

These flash floods and heavy rainfall events are already a problem in cities like Philadelphia that don’t have adequate combined sewer overflow capacity,” Dr. Fitzpatrick noted. In Philadelphia and other cities where sewage systems are combined with storm water drainage systems, heavy rains can overflow the systems, and divert the wastewater into nearby streams and rivers.
Paradoxically, the Midwest also faces the possibility of more frequent short-term droughts in the coming decades due to falling amounts of summer rainfall combined with rising temperatures. Long-term droughts should be less frequent, according to the UCS report.

-when you turn your tap on -- to brush your teeth, to take a shower, to wash your car, to water your lawn, and if you have your own swimming pool then, to fill that as well.So it was with alarm that many of us read the story of Orme, a small town tucked away in the mountains of southern Tennessee that has become a recent symbol of the drought in the southeast. Orme has had to literally ration its water use, by collecting water for a few hours every day -- an everyday experience in most developing countries, but unusual for the U.S. This is an extreme experience from the southeast region that has been under a year long dry spell. In fact, the region's dry spell resulted in the city of Atlanta setting severe water use restrictions and three states, Georgia, Florida and Alabama, going to court over a water allocation dispute (settled in favor of Florida and Alabama early last month).Early this year we also heard that drought in the region could force nuclear reactor shut-downs. Nuclear reactors need billions of gallons of cooling water daily to operate, and in many of the lakes and rivers water levels are getting close to the limit set by the Nuclear Regulatory Commission. It is possible in the coming months that we may see water levels decrease below the intake pipes, or that shallow water could become warmer and unusable as a coolant. While this may not cause blackouts, this can result in increased costs for energy as utilities have to buy from other sources.Water concerns are not restricted to the southeast region -- similar issues have also been popping up in other parts of the United States. In the Midwest, concerns abound as to whether the newly emerging biofuel industry is putting undue pressure on the region's groundwater resources. The issue came into focus for the first time in the late summer of 2006 in Granite Falls, MN where an ethanol plant in its first year of operation depleted the groundwater so much that it had to begin pumping water from the Minnesota River.