California is in the midst of a severe drought and river resources are dwindling. Many rural homeowners and farmers are concerned about having enough water. Modern technology is now being used to locate subsurface groundwater sources to meet those needs.
According to the California Department of Water Resources, last year closed as the driest year in recorded history for many areas of California. Governor Edmund G. Brown declared a drought state of emergency on January 17, 2014. Governor Brown also recently signed legislation to put a comprehensive $7.5 billion water bond before voters this November.
California’s groundwater provides 30 to 46 percent of the state’s total water supply; some communities in California are 100 percent reliant upon groundwater for urban and agricultural use. The UC Davis Center for Watershed Sciences study, released July 15, 2014, stated that it “found that the drought – the third most severe on record – is responsible for the greatest water loss ever seen in California agriculture. Groundwater pumping is expected to replace most river water losses.”
Agriculture uses 80% of the California’s developed water supply. The study also found that direct costs to agriculture total $1.5 billion with net revenue loss about three percent of the state’s total agricultural value; five percent of irrigated cropland is going out of production in the Central Valley and Southern California due to the drought; an additional $6.3 million is expected in pumping costs.
California produces nearly half of U.S.-grown fruits, nuts, and vegetables and nearly a quarter of the nations’ milk and cream. Nationwide, consumers regularly buy several crops grown almost entirely in California, including tomatoes, carrots, broccoli, almonds, walnuts, grapes, olives and figs.
Locally, avocado farmers, grape growers, nurseries and rural homeowners are turning to technology to locate water sources.
“There is water out there,” said Tony Jaramillo of Mount Palomar-based WaterLocating.com. “You just have to use modern technology to locate it and map it for the best source.”
Old western movies depict “water-witchers” or “dousers” holding the ends of a forked twig that rotates downward to signify a source of water. Modern-day dousers use metal rods, but the techniques – scientifically unproven — are the same as used for thousands of years.
According to the USGS, “in regions of adequate rainfall and favorable geology, it is difficult not to drill and find water!”
Today, geophysicists with state-of-the-art instrumentation can image the subsurface of the area; much like an MRI images the human body, to see the inner fractured matrix of the earth to determine the depth, quantity and quality of the groundwater. The induction-based electromagnetic survey method is similar to military-based imaging used to locate enemy submarines.
Computer profiles reveal gravel, sandy and fractured zones where water has the ability to flow. Geologic maps and cross-sections showing the distribution and positions of the different kinds of rocks provide great clues to aquifers of uniform permeability.
“It is the fractured zones that well-drillers want to drill into for a successful water well,” said Jaramillo. “This takes the guesswork out of drilling sites.”
Hydrologists can provide information on the wells near the target area. Locations, depth to water, amount of water pumped, amount of water moving through the aquifer, volume of water that can enter a well, and the effects of pumping on water levels in the area can all be accessed. It is important to match the size, depth and yield of the well to the need.
Drilling a well is expensive, especially if water is not found. Costs vary by project size and location. Drilling companies charge for equipment, material and expertise. There is a mobilization and demobilization cost to move equipment to a site (minimally $300 to $600 depending on the type of the equipment and the distance to the site).
Drillers charge on a per-foot basis. Standard drilling with hollow stem auger rigs in unconsolidated sediment may range from $40-60 per foot for a two-inch well; a four-inch well may cost $50-70 per foot. Rotary rigs are more expensive to operate and may cost $20-30 more per foot. These costs are approximate and may vary by operating firm.
Well development costs – to remove fines and sands that entered the casting – range from $50 to $100 per hour. Installing flush-mount covers and vaults also add to the cost. Crew per diem rates (for projects requiring overnight stays) can range from $150 to $250 per day; containerizing drill cuttings also add cost.
With many wells reaching 600-1000 or more feet, it is important to do the water locating as efficiently as possible to minimize multiple attempts and drilling costs. Using a technology-based company with a successful track record can help ensure that one’s expenditure is an investment and not a “dry hole.”
Editors note: Information for this article was sourced from the California Department of Water Resources, United States Geologic Service, UC Davis Center for Watershed Studies and Tony “The Water Guy” Jaramillo (www.waterlocating.com and www.RadarWater.com).