The history of groundwater in the county dates back to the 1850s
Published in the June 25-July 8, 2014 issue of Morgan Hill Life
By Dennis Kennedy
Dennis Kennedy
As we cope with a severe drought, the state of our local groundwater is vital. In a typical year, about half of the water we use in Santa Clara County is pumped from the ground. The Santa Clara Valley Water District actively manages groundwater basins that span from Palo Alto to Gilroy.
The history of groundwater in Santa Clara County dates back to the 1850s, when local communities began drilling wells to supply water to residents, agriculture and businesses. By 1920, with far more water being pumped than naturally replenished, groundwater levels declined and land subsidence, the broad sagging of the land, occurred over many miles.
The water district was formed in 1929 to address groundwater overdraft and land subsidence. Early water district efforts focused on constructing reservoirs to capture local runoff, and using that water to recharge groundwater through creek beds. These efforts helped groundwater levels to recover somewhat, but explosive population growth after World War II resulted in further strain on groundwater levels.
Two major breakthroughs helped halt groundwater overdraft and subsidence in Santa Clara County. First, in the late ‘60s, Santa Clara County tapped into the State Water Project and imported water began flowing from the Sierra Nevada watersheds through the Sacramento-San Joaquin Delta to our county. Over the next few years, groundwater levels rebounded.
The growth of Silicon Valley continued to expand the region’s need for water. In 1987, imported water began flowing through the federal Central Valley Project into San Luis Reservoir and up to our county. Again, groundwater levels rebounded, despite the six-year drought, which ended in 1992.
This severe drought period, 1987-1992, had a significant impact on the state and our region.
Since 1980, the population of our county has grown nearly 45 percent, yet our water use has remained flat. One reason is that the water district has significantly expanded water conservation. Programs to replace water guzzling toilets and clothes washers began. Low-flow showerheads became the norm, and the district adopted a model ordinance which promoted water-efficient landscape measures.
The water district also began working with local partners to expand the use of recycled water for non-drinking uses, like irrigation and industrial purposes. Both water conservation and recycling reduce the demands on our groundwater or other water supplies.
The groundwater basin is the county’s largest reservoir and our primary reserve during droughts. While future growth of our region will be met primarily through greater conservation and expanded investment of recycled water, the basin beneath our feet is what provides us with the safety margin for continued economic vitality and quality of life.
You can help us protect and preserve our groundwater resources by preventing pollution in our creeks, streams and waterways and by reducing your water use in this drought. There’s never been a better time to take advantage of the water district’s rebate programs, many of which have been doubled until September.
Please visit our Drought Watch page at www.valleywater.org/drought2014 for updated information on the water supply outlook and water conservation rebate programs and tips.
Dennis Kennedy is the appointed representative on the Santa Clara Valley Water District Board of Directors for Morgan Hill residents. For further information, contact him at (408) 265-2600, [email protected].
