Water Whiplash: Corcoran’s levee is being lifted. We’ve been here before
As of mid-May, Tulare Lake had expanded to around 70,000 acres in size.
That’s when Governor Gavin Newsom announced he had set aside part of the state budget to raise the levee that keeps the city of Corcoran above water.
But in a recent article on SJV Water, CEO and editor Lois Henry asked: didn’t the same construction just happen in 2017?
In this interview, KVPR’s Kerry Klein speaks with Lois about the history of the Corcoran levee and its constant tug-of-war with the sinking of land known as subsidence.
Listen to the interview in the player above, and read the transcript below.
LOIS HENRY: All of our rivers come out of the Sierra Nevada to the east of us and then they wash down heading west. But Corcoran's levee is on its west side because it sits right on the shore of the Tulare lake bed, the old Tulare Lake. And so those rivers which actually come, you know, they sort of swoop around the top and the bottom of Corcoran. So it's a little counterintuitive. So their levee actually runs 14 miles. Most of it is running north south along the western edge of town and then there is another arm that comes around the south side of town which actually protects the two state prisons that are there.
KERRY KLEIN: And what does the levee actually look like?
HENRY: It looks like nothing. You would not notice it if you drove by. There is the Cross Creek channel, or it was a creek. It comes down from the north and they’ve channelized it so it looks like just a canal. And then there's just a higher bank on one side of it and you would not notice that if you drove by.
KLEIN: Yeah, that's interesting. So it's not like a big imposing embankment, anything like that.
HENRY: No, it's not. It's not towering over you, you don't drive up to it and feel, you know, this sort of awestruck, like wow, this thing is huge. And by the way, you can drive on it. It's 8th Avenue. So people fish on it, they hike on it, they jog on it. You know, it's a well-used facility.
KLEIN: So as of earlier this winter it stood at 188 feet elevation, but that's not how high it was supposed to be or it originally was.
HENRY: Right. So it gets a little murky going back too far into the history. But I think the Army Corps of Engineers built it in the 70s and then rebuilt it in the 80s and built it to 195 feet. Then in 2017, when we had another big water year, the Cross Creek Flood Control District, which is actually the district that maintains it, looked at the snow in the Sierras and knew that there was potential for flooding, looked at its elevation maps and saw that it had sunk to 188 feet. So in 2017, they went to work rebuilding the levee and it was a mad scramble. This all started from March to April and they got it rebuilt to 192 feet in 2017. It didn't flood that year and everything was good. But then come this year, I got the new elevation maps which were shot in March of 2023 just as flooding got underway and 192-foot levee that cost 10 million dollars back in 2017 had sunk back again down to 188 feet.
KLEIN: So it sank four feet in six years. That's astounding.
HENRY: Yes. It is astounding, unless you also go back and look at some of the stuff I've written about the pumping, the groundwater pumping that goes on there. The pumping has been nothing short of insane in that area. And we're going to mention the J.G. Boswell Company because they are the largest pumpers in that area, bar none, hands down, absolutely. According to testimony that I've listened to…and it's very hard, you can't get them to call you and talk to you, I've asked them a million times. But according to testimony in a legal case, their water resources manager Mark Unruh said they have the capability of pumping enough water to fill a swimming pool literally in five minutes, and they pump all the time because the irrigate year-round. And most of their wells are right there just west of Corcoran and just to the east on the south side.
KLEIN: Right, and so now work is being done to raise the levee again. What elevation level are they aiming for, and how does that jive with expectations of how high the water could actually get?
HENRY: Well, I think they're mostly finished and they wanted to get it to 192 feet. The water is estimated to be at 179 feet of elevation right now and Department of Water Resources projections are that it may get up to 185 feet. So with the levee at 192 should be good enough if that all comes to pass in that manner. And there so they're not just raising it but they're also pushing a lot of dirt up in different sections, sort of creating mullets. The old the old hairstyle is what I'm talking about here, up against the different parts of the levee to try and strengthen it from the back side because they have water on it already and they're anticipating having water on it for the better part of a year at least and that just does nothing but cause great erosion. And in fact, from the air, you can see there's the levee and then there's the canal and then there's the canal bank. Usually you would see those sort of stripes from the air. Well, now that canal bank has already given way and you can see. So the Cross Creek has breached, in places, that barrier and is flooding out into the Tulare Lake.
KLEIN: Wow, wow. Lois Henry, CEO and editor of SJV Water, thank you so much for speaking with me. I look forward to talking about this more later this spring.
HENRY: Thank you.