Got Water Part 2
When you turn on the tap, you have the expectation that water will begin to flow from the faucet. The phenomenon of water flowing from our tap is all too expected. What if you turned on the tap and nothing happened?
The entire Hetch Hetchy water supply system is managed and operated by the San Francisco Public Utilities Commission (SFPUC) and consists of a series of reservoirs, tunnels and pipelines, and treatment plants. The drinking water provided by the system is among the purest in the world.
To reach our homes in Foster City as well as the other 2.4 million people in four Bay Area counties, water passes through an intricate and complex water delivery network. To illustrate the complexity of the system, consider the following flow of water through watersheds, reservoirs, treatment plants and ultimately to your house.
The Hetch Hetchy Reservoir, the main supplier of our water, is within the approximately 450 square mile Toulumne River watershed. The Hetch Hetchy Reservoir provides approximately 85 percent of our freshwater while the Peninsula and Alameda Watersheds combine to provide the remaining 15 percent.
Water from the Alameda Watershed is stored in two reservoirs. The Sunol Water Treatment Plant treats the water from these two reservoirs and blends it with water from the Hetch Hetchy Reservoir. The water is then piped to the Crystal Springs Reservoir.
The Peninsula Watershed (Crystal Springs) is an area of about 23,000 acres containing the San Andreas, Crystal Springs, and Pilarcitos Reservoirs. The Harry Tracy Water Treatment Plant filters and treats water from these three reservoirs before the water is distributed to San Francisco and cities along the peninsula.
The above is a simplified description of the Hetch Hetchy water system but I hope that it gives you an appreciation of the water that flows from your faucet.
When the Hetch Hetchy system was devised, there was some ingenious forethought put into the development of the project.
Water from the Hetch Hetchy system leaves the Yosemite Park and reaches San Francisco and cities along the peninsula without the use of any manmade energy. The water moves through the entire 150 mile system by gravity except to the higher elevations on the Peninsula and San Francisco. There are no fossil fuels consumed to move the water from the higher elevations in the Sierras to our sea level location.
To address the aging infrastructure of our water system, legislation was passed that required the SFPUC to adopt a $2.9 billion capital improvement program in May of 2002. The improvements will upgrade the reliability of the system with particular attention to seismic issues.
The system is from 75 to 100 years old crossing major active earthquake fault lines; suffice it to say it does not meet the seismic standards of today. The cost of the improvements will be borne proportionately by customers in San Francisco, San Mateo, Alameda, and Santa Clara counties.
This article addresses several water sources and a little information about them, but what has not been mentioned is what I term the “nature made reservoir” – the Sierra snow pack. As we all know there are two benefits of reservoir captured water, a manageable water resource and electric power generation.
Mother Nature has long provided the energy to raise water from the oceans and dump it on the mountain tops in the form of snow. The snow is built up on mountains at the higher elevations during the winter months and slowly melts in the spring and summer months providing a natural reservoir. As climate temperatures rise, snow melts faster so the same volume of precipitation must either be stored in manmade reservoirs or it could be lost as it rushes to the sea.
To address a longer term water supply solution, a desalination exploration project is underway with joint participation from the four largest water agencies, San Francisco Public Utilities Commission, Contra Costa Water District, East Bay Municipal Utility District, and the Santa Clara Valley Water District.
These agencies are exploring the possibility of attaining a long term capacity of 71 million gallons per day of fresh water from our encircled Bay. A feasibility study has been completed and a grant has been obtained to build a test desalination plant in Contra Costa County. It is expected that the designs will be begin in 2010 and construction in 2012.
Our City is one of more than 25 cities and water districts belonging to the Bay Area Water Supply and Conservation Agency (BAWSCA). This agency was established to address water resources for both current and future availability. The goals of BAWSCA are to provide a reliable and high quality water supply at a fair price and to encourage water conservation.
Now that you know a little more about our complex water system, I hope that you will do your part to conserve our precious water resource so that we continue to “Have Water”.
For more information on our complex water system, the following sources of information are available:
• Bay Area Water Supply and Conservation Agency (BAWSCA)
• San Francisco Public Utilities Commission
• Bay Area Regional Desalination Project
I would appreciate your comments on this and other issues by emailing me at firstname.lastname@example.org.
September 17, 2008
Got Water Part 2
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