Solve California drought/flood crisis with a better groundwater approach

With the massive amounts of rain across California over the last few weeks, the question is "Why don’t we capture all this water for the drought season?”

Good idea indeed. Usually the normal answer is "build more dams" to store water. Until you realize that of the 20 inches of annual rainfall on average, we lose 15 inches to evaporation! Reservoirs are a terrible way to store and save water. In fact, it is as if we are collecting surface water as a 75% tax offering for the gods of evaporation!

This leads me to the main point I want to make – the best way to capture rainwater is underground. California has massive groundwater potential and there are significant benefits to refreshing aquifers as opposed to building dams and reservoirs.

• Reduce evaporative loss – compared to surface water in large open reservoirs
• Cheaper. Much, much cheaper – compared to the cost, environmental impact and time it will take to build large dams and reservoirs
• No lost land – large reservoirs take up large amounts of land, which we can ill afford to lose
• No need to transport water – the Colorado basin is in trouble and plans to bring water from Lake Tahoe are insane
• Reduce temperatures – groundwater enables the earth to “sweat” thus reducing surrounding temperatures

The JalTara approach – One Recharge Pit per Acre

What I propose is the JalTara approach to solving for groundwater. This is something that we have successfully demonstrated on approximately 19,000 acres of land in dry regions of Maharashtra state in India. We dug one simple recharge pit (6 feet deep, 4 feet across) per acre of arable land – at its lowest point, allowing monsoon rainwaters to flow and percolate underground. This region gets about 700mm (27inches) of annual rainfall – and we have managed to absolutely transform 37 villages.

• Water tables have improved 14 feet from summer to summer – even with increased extraction of available water for irrigation.
• Crop yields have increased by 42% - due to availability of water for consistent irrigation, increasing land productivity by 58% and thus farmer incomes by 120%
• And another interesting point is near total elimination of crop spoilage due to waterlogged fields from atmospheric events like we see in California.

The bold goal in India is to dig 50 million such recharge pits across 100,000 of the most drought impacted villages – within five years. This is only possible, because JalTara is an incredibly scalable approach.

There is no reason to not replicate this "one-recharge pit-per-acre" concept in central California and store trillions of gallons of water during such massive atmospheric events.

California has about 25 million acres under cultivation. If we dig 6 feet deep, small, recharge pits in every acre and assume that we store about 15% of annual rainfall, we have the ability to save over 10 trillion liters of groundwater annually. That is more than the combined capacity of Lake Shasta and Oroville (the largest two reservoirs in California) - and more than five times (more than ten times if you include evaporation losses) the capacity of the new proposed Sites Reservoir at a fraction of the cost and time needed.

Friends, groundwater in the answer. And the JalTara approach is the 42 we have all been looking for :)