So what’s going to be costlier when it comes to your pocketbook — the drought or a hypothetical 200-year flood event?
Even if food prices jump, you buy a high efficiency washing machine, and you have to tear out some of your lawn and put in landscaping that sips water you’re going to get off cheap.
The costliest of the two is the crisis created by decree of the California Legislature — the 200-year flood. That same august body and the bureaucratic hordes that populate Sacramento have also made the solution to their mandate one-dimensional — building bigger and stronger levees.
It is why Manteca and Lathrop residents are facing at least a $160 million tab before factoring in interest to guard against an event of nature that has such an intensity the odds are it will happen, on average, once every 200 or so years.
Regardless of whether you embrace climate change scenarios there is scientific evidence derived from tree rings that the last century was abnormally wet in the western United States. There is a strong possibility based on tree ring studies that we are in the start of a mega-drought, events that have lasted 10 to 50 years.
That said, doesn’t it make sense to be prepared in case it rains for 40 days and 40 nights?
Caution is always good. You can be too cautious, though. And you can also over engineer solutions especially when politicians force you to solve a problem with one hand tied behind your back.
Since the 1950s the silt buildup between Vernalis and Mossdale on the San Joaquin River southwest of Manteca has raised the bottom of the river from eight to 10 feet. In the late19th century, massive vessels used to make their way up the San Joaquin River as far as San Joaquin City south of Vernalis before railroads put them out of business. The vessels couldn’t make the same trip today. That’s due to the silt build-up triggered by government encouraged run-off from the Westside irrigation efforts that deposited soil in the San Joaquin River.
You can increase the volume of the river channel not by setting levees farther back or building them higher — two expensive propositions — but by dredging the silt build-up.
So why not do it? The short answer is because bureaucrats have decreed the higher river bottom is now part of the environment. It is the same logic they used to block the removal of sand bars in the concrete-lined Los Angeles River.
If you did dredge the river you would have to widen the bend at Mossdale and shore the levees up. But after the water gets past Mossdale it splits into two channels — the Old River and the main river — to reduce pressure.
While levee work would still need to be done to meet the state mandate it likely wouldn’t have to be as extensive as the increased carrying capacity of the river would alter modeling.
Then there is the issue of how the government operates reservoirs. In the devastating 1997 flood that caused $100 million in damages south of Manteca, the Bureau of Reclamation didn’t react to a massive late December runoff caused by heavy snow followed by extensive unseasonable warm rain until New Melones was almost breached. And even when they started maximum outflow it was touch and go for several days. Meanwhile other reservoirs including Friant had finally been increasing releases to keep other reservoirs from overflowing. The result was the New Melones releases on the Stanislaus River and those from Friant and other reservoirs feeding the San Joaquin River arrived basically at the same time at the confluence of the two rivers triggering the levee breaks. Had the dry levee south of Manteca failed after the river levees failed, the federal government would have been culpable for the damage that would have happened to perhaps 1,000 Manteca homes. Of course, the government holds itself harmless for its bonehead decisions.
Manteca-Lathrop isn’t the only urban area in California being slammed with having to put 200-year flood protection in place or else face having all building — including alterations to existing structures — stopped.
Given we are in the Age of Computers and satellites one would think modeling for more appropriate operation of reservoirs and water releases while monitoring weather and snow conditions could be done to reduce the risk of a 200-year flooding occurrence but the 100-year variety that have been occurring every 10 to 30 years.
Some of that is due to aging levees with substandard materials and maintenance gaps driven in part by the inability of reclamation districts to kill burrowing rodents such as gophers without having to go through a lengthy environmental review process with the hope at the end the great and powerful wizards in Sacramento will grant them the permission to do the obvious.
There are those that argue the current water shortage is caused in part by government decree particularly how it pertains to releases for fish. While that may be true, if the drought drags on for a couple of more years it would negate that charge somewhat.
There is little doubt, however, that the current concern with a 200-year flood is the direct result of the California Legislature and not Mother Nature telling us that it is so.