Water Resources Engineering (WRE) connects to economic, environmental, and societal issues. Our student Gus Walker makes this connection in Los Angeles, California. This current event was reported in Los Angeles Times, on April 17th 2017 under the title, “One key way soggy California could save water for the next dry spell”, by Bettina Boxall. This is likely real news, based on independent reporting on this event at here.

The story about unorthodox ways to replenish aquifers relates to water resources engineering, in the specific disciplines of hydrology and resource management. The main message of the article is the importance of ground water recharge to the San Joaquin Valley aquifer to ensure future water availability. The San Joaquin Valley aquifer has been pumped for over a century and this has causes a dramatic drop in water table levels, especially over the last 5 years’ drought period. The recharge of this massive aquifer could be the key to solving California’s cyclic water cycle. Dry southern California’s water system greatly depends on the climate in the wetter northern zones. During massive spring runoff events, there is often an excess of water that gets sent down stream and not stored for the drier season. Don Cameron, a vineyard owner, thinks the solution to the water crisis is recharge of the massive and depleted San Joaquin Valley aquifer. He witnessed that his grape harvest was not adversely effected by his fields being flooded with water for a month in the early spring. By letting the water sit in the fields for an extended period it allows for infiltration and percolation of that water into the aquifer. However, I do think the author overlooked some important details in the applicability of this concept. I believe further research would have to be done to test soils to ensure the water will mostly make it to the deep saturated zones of the soils versus being transported to rivers and carried downstream. Also by spreading this water out over large areas the rate of evapotranspiration will likely increase and be mistaken for recharge.

Figure 1. Sinking of ground from May 2015 to Sept 2016 due to groundwater pumping

The importance of groundwater recharge in this area of the world can be seen though an economic, environmental and social lens. If this method is proven to be viable and effective if has the potential to dramatically improve California’s water management issues. At certain times of the year in southern California the price of water is high due to the shortages in the whole state. This puts economic stress on the people who consume water and the government to spend money on storage systems to store water for these times. The environmental impacts of not recharging the aquifer can be devastating. By drawing down the water table and never replenishing it ecosystems won’t function in the same way. An example of this was showed by a recent NASA study that shows the San Joaquin Valley is sinking due to groundwater pumping with no recharge. The ground is sinking up to 24 inches in some places as shown in figure 1 (NASA 2017).  And that water won’t be there for irrigation of crops in the future.  The societal impacts of not having adequate water storage are endless. The article stated that if farmers in the valley don’t take ground water recharge into consideration they may not have water to grown craps at all in the future. If don is right then that would mean many wineries would be forced to close due to having no crops.

Reference

Alan Buis, NASA Data Shows California’s San Joaquin Valley Still Sinking. NASA.gov. March 1, 2017.

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