Earth fissures undermining foundations of growth - East Valley Tribune: Queen Creek & San Tan Valley

Earth fissures undermining foundations of growth

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Posted: Sunday, February 26, 2006 5:01 am | Updated: 3:53 pm, Fri Oct 7, 2011.

The small exurban area saw its population grow from less than 10,000 to more than 30,000 within a decade. Land that was once agricultural became subdivisions and shopping centers seemingly overnight. The growth appeared unstoppable, until one August, when giant cracks in the land split open in a new housing development.

Fissures cracked a residential street and damaged the foundations of homes, startling residents who suddenly weren’t sure what they were living on.

The story could easily describe the Queen Creek area now. But it’s actually about Temecula, a Southern California city that experienced its massive growth and tangles with earth fissures years before in the mid-1980s.

Geologic and hydrologic experts, along with longtime residents, say that unless something is done, it’s only a matter of time before the story plays out in Queen Creek the way it did in Temecula.

“By early 1988, more than 200 lawsuits alleging more than $25 million in damages had been filed against the developers, the County of Riverside, the local water district, and several geologic and soils engineering consulting firms,” wrote a trio of San Diego attorneys who conducted a 1991 case study of the litigious effects of fissures in Temecula.

“Total costs will ultimately exceed at least tenfold the value of the structures allegedly damaged by the fissures,” the study states.

Riverside County initially instituted a total ban on building permits and then passed an ordinance requiring structural and geotechnical evaluations and prohibiting new buildings from being built on fissured land. Real estate agents scrambled to reassure buyers and keep escrow closings from failing.

Wells, which contribute to the land subsidence that can cause fissures by removing groundwater, were promptly shut down. Developers were forced to buy back several newly constructed houses, move others that were astride fissures, pay for extensive geotechnical surveys and excavate a fissure that had been filled with dirt to determine its true path.

Some residents left the area in fear of the fissures; others experienced emotional problems from the anxiety of finding they lived on or near giant cracks that could extend hundreds of feet underground. Some said they had difficulty selling their property, and there were reports that real estate brokers were shunning the area and home values were falling, the case study states.


Litigation over fissures in Arizona is bound to happen, just like it did in California, said Herb Schumann, a hydrologist and Tempe-based consultant.

“California got into a lot of problems with this before Arizona did,” he said. “It is an ongoing battle out there in certain areas.”

Schumann said he wouldn’t be surprised if a lawsuit was filed over fissures in an area near Queen Creek.

“Look, this is a hazard,” he said. “It’s going to bite you if you don’t know that it’s there; it’s like a snake. Someday, it’s going to bite somebody, and it’ll bite them hard enough that they’ll want to sue.”

Fissures can stay hidden because they form from the bottom up as basin land slowly sinks when groundwater is pumped out of underground aquifers. The cracks are usually just a few inches wide, and most often form where basin meets bedrock or mountains.

Since the Valley has subsided 100 to 500 feet since 1900, there are probably fissures that deep, said Ray Harris, a research geologist with the Tucson-based Arizona Geological Survey. But the cracks usually only catch people’s attention after a big rainstorm or runoff when water floods the crack at the surface and erodes it into a giant, seemingly bottomless chasm.

This happened in an unincorporated area near Queen Creek last August. Monsoon rains opened part of a Y-shaped fissure that has existed there since at least the 1960s. An Arizona Department of Real Estate investigation into properties affected by that fissure is ongoing, and the danger is still there.

“It can still open up years after subsidence has stopped,” Harris said.

Subsidence has slowed in Queen Creek, but groundwater pumping is ongoing, and the Phoenix area pumps out 250,000 acre feet more than is replenished each year on average, according to the Arizona Department of Water Resources. There are plans to remedy that deficit, but not fully until at least 2025 and the ongoing drought will make reaching that goal difficult, department officials said. Meanwhile, the Valley keeps sinking.

And this year’s monsoon could bring more rain than last year’s, according to the National Weather Service, so the Y-crack or other fissures in the area may surface spectacularly again.

Schumann said it’s best for municipalities to be prepared.

“Some of the cities, they don’t want to admit that they have this problem,” he said. “As far as Queen Creek is concerned, it would be very smart to consider some zoning.”


Queen Creek recently took a step toward dealing with earth fissures as it made its largest foray into planning for development in Pinal County. The town commissioned a $75,000 study for a San Tan Foothills Area Plan in December, covering a 10-square-mile swath of land south of Hunt Highway. A big part of the study will involve determining how the town might develop around fissures.

There could be a lot of cracks to look out for. Compared to Maricopa County, Pinal County has about 20 times the number of earth fissures — appearing on a map as if someone crunched up spaghetti noodles and scattered the pieces over the county, Harris said.

Builders expecting to develop in Pinal County are going to have to deal with those cracks.

Doug Adcox, owner of San Tan Homes, already knows about that process. He’s been working with Queen Creek to build a small subdivision of semicustom homes on 15 acres southeast of the intersection of Hunt Highway and Sossaman Road — a project some residents have called unsafe. One leg of the Y-shaped fissure extends on to the land proposed for the homes.

Adcox said the company knew about the fissure before it requested geotechnical surveys of the land. More studies are now being done because a town expert disagreed with an initial evaluation, he said. The proposed subdivision is within Queen Creek’s boundaries, so the company must seek approvals from the town.

Adcox said the studies could help determine how the development could be constructed around the fissure.

“We just want to make sure we get the straight story,” he said. “All I know is that there is an issue, and we’re going to deal with it.”

Experts said the first step in dealing with fissure issues is knowing where the cracks are.

“If you do know it’s there, and you know what it’s like, you can engineer for it and protect yourself,” Schumann said. “It’s not pleasant and it’s not cheap, but you can live with it. If you’re building a house down there, you’re going to spend a quarter- to half-million dollars — a few thousand dollars for a geotechnical study is not that much.”

Installing post-tensioned (reinforced) concrete slabs on a foundation and provisions to protect utility lines may seem expensive — at $10,000 to $20,000 to protect a new home against fissures — but it’s due diligence, Schumann said. Just telling people to build elsewhere is not a permanent solution.

“You can’t save them from themselves much of the time, but they deserve to be warned. Just saying, ‘No, go away, don’t do this,’ is not a solution,” he said. “If Arizona keeps growing like this, there’s not much land left to go to.”

As development encroaches on fissures, experts such as Schumann are often asked how close they would put a house to a fissure. It’s a difficult question to answer, he said.

“I’ve heard all kinds of numbers; one of the ones that seems to come up rather frequently is 50 feet,” Schumann said. “In my opinion, that’s a bare minimum; I’d be more comfortable with 100. And for God’s sakes, don’t build on top of it.”


People have been able to build homes on top of fissures in Arizona, and then sell them to unsuspecting buyers for a couple of reasons. One: Arizona law doesn’t require geotechnical studies on land that’s split into five or fewer lots for homes. And two: State funding for accurate mapping of the fissures has been near nonexistent.

“They turned us down for funding to do fissure-mapping a year ago,” said Harris, the Arizona Geological Survey research geologist. “We’d be halfway done with this whole thing by now. Then, in August, suddenly there’s a big whoop-dee-doo.”

The state failed to fund an Arizona Geological Survey budget request for a full-time position to update the fissure maps in early 2005, Harris said. That was before the Y-crack near Queen Creek opened up — the “big whoop-deedoo.” The newest map of that fissure was completed in 1994, via the fairly primitive method of eyeballing the crack on an aerial photo and then duplicating it on drafting paper.

Nobody really cared that the maps were old and inherently a bit inaccurate, Harris said, because nobody had been affected by the fissures for years.

“There’s blame to go around on just about every level,” he said. “Nobody picked up the ball.”

Because “nobody picked up the ball” and required more stringent disclosure laws or more recent fissure mapping, homeowners such as Joan Etzenhouser can be left picking up the pieces.

Etzenhouser learned last fall that she has an earth fissure under her home near the intersection of Sun Dance Drive and Wagon Wheel Road in Pinal County. Two more fissures are on land she owns surrounding her house. The geologic hazards, which barely show at the surface as odd, little holes in her yard, were never disclosed to Etzenhouser when she bought the home about two years ago.

“Some of the cracks are spreading on their own, even without water,” she said. “There isn’t a whole lot I can do about it, besides hope it doesn’t rain too much.”

Etzenhouser is looking into filing a claim with the Arizona Department of Real Estate and talking to an attorney. She’s asked Pinal County, which issued a building permit for her home in 2001, for $1,500 to have a thorough, geotechnical evaluation done on her property, but hasn’t heard back.

“It’s just going to keep happening, the more people use water,” Etzenhouser said. “I just happen to be in a place that I didn’t bargain for. I could never sell it, and I don’t want a rental.”


Potential buyers fearful of ending up like Etzenhouser have been keeping Harris busy this year.

“There are days when all I do is return e-mails and answer phone calls (about earth fissures),” he said, holding up a stack of multicolored messages three inches thick from the past five months.

To help illustrate the potential catastrophic effects of fissures, Harris has a PowerPoint presentation that he uses for the “oohaah factor,” he said. The slides show undeveloped land with earth fissures on it, and then, with a click of the mouse, the fissure seems to have disappeared and homes are built near, even on top, of its path. It’s all development that’s happened within the last decade.

“It’s scary,” Harris said. “There’s places where it’s going to be essentially impossible to map these because they’ve been developed. And on agricultural land, you have to get just the right year of aerial photo. Even if there were fissures, you’d never be able to see them.”

Though out of sight, and, for most, out of mind, the fissures are there, and some are growing. At Baseline and Meridian roads, a fissure cuts diagonally underneath the intersection. It’s an area of active subsidence, and the fissure has grown about a quarter-mile on its south end, just in the last few years, Harris said.

“We’re not a regulatory agency, so we can’t tell people not to build on earth fissures,” he said. “We can tell them where they are.”

But sometimes people just don’t want to know or don’t care about hidden geologic hazards.

“California did the same thing in the 1970s with earthquake faults,” Harris said. “That took 30 or 40 years of people ignoring the problem. What it takes is usually 20 to 40 years of people’s houses being ruined. And finally enough government agencies come together to do something about it. That’s what’s happening with earth fissures right now.”

Harris predicts that, with the continuing drought, Arizonans will have another hazard to contend with soon enough. Giant dessication cracks are supersized mud cracks, like those that form when a puddle or a riverbed dries up. Dessication cracks as long as earth fissures, but not nearly as deep, are forming in Arizona as the clay soil shrinks and dries in a yearslong drought.

“Giant dessication cracks are going to be as bad as earth fissures,” Harris said. “They haven’t made the news yet, but they will.”


Queen Creek resident Silvia Centoz said she knew earth fissures were going to make the news again about eight months before it happened.

On New Year’s Eve in 2004, Centoz was driving west on San Tan Boulevard, east of Sossaman Road, when her truck bottomed out on the fifth dip in the road. Dips in the road large enough to damage the axles of cars aren’t unusual on county roads near the town, but that dip wasn’t normally that way, Centoz said.

She had been told by a longtime resident that when vehicles begin bottoming out at that spot in the road, it means the land is shifting and it’s only a matter of time before the earth fissure that appears on geologic maps as an upside-down “Y” splits open again.

Eight months later, after a heavy August monsoon rain, homeowners at 195th Street and Happy Road — an intersection near the stem of the Y-crack — found themselves staring deep into a 15-foot-wide crack.

Centoz knows about earth fissures because she’s been living near them and talking to geologists and hydrologists about them, for more than 20 years.

For much of that time, she’s been trying to warn people, municipalities and developers about them. She’s not afraid to talk tough with developers about the dangers of building on a fissure.

“I was always told they’d find me in a fissure crack dead someday,” she said.

Centoz may use a more intuitive approach to predict when fissures will open, but she’s certain about one thing: They will open.

Near the intersection of Sossaman Road and Hunt Highway, she can point out a fissure that opened in 1962 and was filled with 17 40-cubic-yard containers of bedrock. When the fissure reopened 10 years later, the bedrock was nowhere to be found.

“We would take a flashlight and shine it down there and throw rocks and you couldn’t hear them land,” she said.

Today, homes sit perilously close to that once-bottomless crack. It looks like a wash, but a good rain would reveal its true nature.

“These are brand new homes,” Centoz said, surveying a burgeoning development and the path of the fissure. “This is only the start of what will occur.”


Because growth has relatively just begun in Pinal County, there is still time to prevent and mitigate the effects of earth fissures, experts said.

“Pinal County, there’s still a chance of doing some good,” Harris said.

“Maricopa County’s kind of a lost cause right now. But Pinal and Cochise are full of fissures. There’s still an opportunity to warn people.”

With areas that are experiencing explosive growth, the danger is “if they explode in the wrong areas before we get these fissures mapped,” Harris said.

Two bills introduced in the Legislature this year could help the maps keep pace with growth.

A House bill would require regularly updated, digital mapping of earth fissures utilizing global positioning technology. Harris said such maps would be much more accurate than the current ones, but would take up to two years to complete.

A Senate bill would mandate increased disclosure of earth fissures by property owners selling five or fewer lots.

But the bills still have to pass, and an appropriation of hundreds of thousands of dollars is needed for the mapping.

So, in the meantime, Harris spends a lot of his time warning people that fissures may not be a big problem today, “but when more people move out there, it’s going to be.”

And it’s happening. People are moving “out there,” more everyday. People who could take a lesson from what happened to a little exurb in the desert, about two decades ago, in California.

“The Temecula area fissure litigation points out that urbanization, especially in geologically sensitive locations, will continue to cause increasing friction between developers, federal, state and local regulatory authorities, utility concerns, and private business and residential interests,” the case study concludes. “Cooperation at the earliest stages of development planning is therefore crucial to prevent disruption or injury to the environment, to property, and to the health and safety of individuals, and to minimize related litigation.”

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