Farmers replenish area’s aquifer; it’s worth the so-called ‘water subsidy’

Flood irrigation doesn’t just benefit almond orchards; some of the water passes through the ground into aquifers below. Storing water there has been a tremendous benefit to Modesto and everyone who lives in it.
Flood irrigation doesn’t just benefit almond orchards; some of the water passes through the ground into aquifers below. Storing water there has been a tremendous benefit to Modesto and everyone who lives in it. The Modesto Bee

The potential class-action lawsuit against Modesto Irrigation District claiming an unfair subsidy for water users at the expense of electricity customers might cost local farmers a lot of money. But the real cost could be to the water stored underground that we all rely on and to our region’s economy.

The Bee reported in September that the lawsuit is on hold until the California Supreme Court decides on a similar case out of Redding. If the suit is successful the price of water could rise significantly. That will encourage farmers to use drip irrigation instead of flooding their fields due to rising costs, reducing water that replenishes the aquifer.

Some people say MID has a $93 million per year profit on electricity. Others point to a much-lower annual “water subsidy” of $17 million per year. There is no official figure. So let’s use the lower figure.

There are roughly 60,000 irrigated acres in MID. If the “subsidy” is correct, then costs for irrigation would rise from roughly $48 per acre now to $283. For high-profit products such as almonds, that shouldn’t be a problem; for low-profit crops, such an increase will be significant.

Since 1994, the city of Modesto has used about equal amounts of groundwater and treated river water for urban needs. However, during the most recent drought, river flow was down and about 60 percent of the city’s water came from under ground. A longer, or more intense drought would force the city to rely even more heavily on groundwater.

Groundwater volume under and near Modesto is many times greater than what’s in our reservoirs; under a 2014 state law, this volume must be maintained. Flood irrigation contributes to this underground water supply.

But if farmers move to drip irrigation, or pump on a large scale (which they would do in a major drought), they will begin competing with the city for groundwater rather than supplying it.

Farmers use far more water than the city of Modesto. So the water table under Modesto could see major outflows rather than inflows as farmers pump more. It is in Modesto’s best interest to keep the groundwater table high.

Stanislaus County farmers have generated an average of $3.69 billion per year over the past five years. Much of that is rolls many times through our economy, making agriculture’s economic contribution at least three times greater. It is reasonable to put agriculture’s value to the local economy at $10 billion per year. That supports a lot of non-farm jobs, including those of the people filing the lawsuit.

That $10 billion covers the entire county; so how much came from farms within MID? There are roughly 450,000 irrigated acres in Stanislaus County, with MID making up 13 percent. But farms in MID grow mostly high-value crops compared to field crops more frequently grown farther west. Let’s say Modesto’s farmers create 15 percent of the county’s gross ag product. That means for a so-called “subisidy” of $17 million, the community gets $1.5 billion in overall benefit.

Why wouldn’t the community want to encourage such a beneficial activity?

The recharge of shared groundwater aquifers by flood irrigation in exchange for aid from electric ratepayers is smart. We are much better off in available groundwater than almost anywhere else in the Valley. In a severe drought, this is a tremendous advantage.

Tripling the cost of flood irrigation will encourage farmers to use more groundwater and cause long-term harm. Farmers should be encouraged to recharge groundwater to the maximum extent possible, not deplete it.

There is no easy way to calculate the value of groundwater stored by farmers. During a truly long drought, it can be worth thousands of dollars per acre foot. During a wet period, only a fraction of that.

Long-term planning is imperative! I doubt the courts are qualified to do the job.

Vance Kennedy is a retired USGS geologist and citrus farmer in Modesto. He wrote this for The Modesto Bee.