Expansive Soils Destroy Buildings

Carl Brahe

Expansive Soil - Colorado is home to expansive soil, commonly bentonite. The leading cause of foundation damage in this type of soil is uneven moisture. Drying soil can shift and crack your foundation as it shrinks. When moisture in applied the resulting swelling can crumble your foundation and actually break your house in two, if your basement is not properly framed. There are other dangers from water movement in the soil

Inspecting for moisture conditions that could cause damage to your foundation -
Dirt should slope away from all sides of your foundation six inches in ten feet. When this is not possible a French drain, or other drainage method, is used to drain water away from the foundation. You may notice cracks in walls and ceilings. Doors and windows may stick. This may be the result of uneven moisture under your foundation. If water drains away from three sides of your house, but brings the water to the foundation on the other side, extensive damage to your foundation may result.

Clay and organic matter in soil expands when wet and shrinks when dry. Most foundations in Colorado are made to float on the expanding and contracting soil. If the moisture is even around the entire foundation the expansion and contraction will be uniform. The foundation will float as a single unit and remain undamaged. If one section expands, lifting the house, while the rest doesn’t, the foundation can break.

A simple way to test for uneven moisture levels around your foundation is to use an inexpensive plant watering gauge. These are available at hardware stores for around $10.

The gauge has two long, metal probes that are pushed into soil to measure water content. Measure the moisture content in the soil around your foundation at 10' intervals. Test the moisture levels about 1' from the foundation. Move around the entire house mapping moisture levels around the foundation.

If you find that the moisture levels are higher in some places than others, it is likely you will find some sign of foundation movement around the areas of higher moisture. This may result in doors and windows that stick, or cracks in walls, ceiling or foundation.

Most foundations in Colorado are made to float on the expanding and contracting soil. If the moisture is even around the entire foundation the expansion and contraction will be uniform. The foundation will float as a single unit and remain undamaged.

If moisture is uneven simple measure can usually be taken to correct the problem. In areas where the moisture content of the soil is higher than others direct runoff water way from the foundation. Make sure the dirt slopes away from all sides of the house and all gutters and downspouts are in working condition. Be sure sprinklers don't spray against the foundation or side of the house.

In some cases expensive retaining walls and/or French drains may be needed. If you have doubts consult a landscape engineer or architect.

Testing for expansive soils is not a usual part of a home inspection.

Denver and the West
Warnings did not stop development in Colorado Springs' landslide zone
City officials have known about slide problems since 1990s but development has gone on almost unabated

By Ryan Maye Handy
Special to The Denver Post
Posted:   04/22/2016 04:42:19 PM MDT172 Comments | Updated:   about 7 hours ago
1/5

This home belonging to Rick Sisco on Constellation drive has become a victim to the ancient landslides that are being found along the foothills on April 11, 2016 in Colorado Springs, Colorado. Over 200 homeowners in the city have applied for federal bailouts because their homes are being eaten up ...

COLORADO SPRINGS — A geologist knocked on Sherry Cripps' door more than a decade ago and warned her that her home on Cheyenne Mountain was sitting atop a slow-moving, destructive landslide. He told her to abandon the home.
Cripps dismissed the aging geologist as crazy until 2015, when his predictions came true. She and her husband Denny are close to abandoning their nearly unlivable home, as it is cracking in half and sliding off a hill. The Cripps and their neighbors are confronting a behemoth that lay dormant for years: a landslide zone one and a half times the size of Manhattan.
Thousands of homes in the southwest corner of the city were built in the slide zone, despite repeated warnings from geologists who said the area was risky for development and recommended caution in approving construction.

Homeowner Denny Cripps is barely able to open this sliding wooden door in his home in Broadmoor Bluffs on April 11, 2016 in Colorado Springs, Colorado. There are cracks that run all along the ceiling, down the wall and into the doorway. The Cripps are among 200 homeowners who have applied for federal bailouts because their home is being eaten up by collapsing expansive soil that is part of an ancient and massive landslide area. (Helen H. Richardson, The Denver Post)
City officials have known about the problem since at least the mid-1990s, when they passed an ordinance designed to restrict development, but the measure has not been enforced and new homes have gone up almost unabated.
In other parts of the state where similar problems have occurred — including Boulder and Jefferson counties — landuse code prohibits building on known landslide areas.

Insurance will not cover the losses. At least 70 homeowners in southwest Colorado Springs are seeking federal grants to help buy out their destroyed or imperiled houses — the third round of such funding for the city. Nineteen of those properties are located in neighborhoods surrounding a Broadmoor Hotel golf course where a landslide has been an issue for years.

(Severiano Galvan, The Denver Post)
"In my mind, the process threw caution to the wind," said Jon White, a geologist with the Colorado Geological Survey. "Many knew the risks. Everybody should have been more cautious and the risks should have been disclosed to the potential homebuyers."

The Cripps and other homeowners near Cheyenne Mountain say they were the last to learn of the danger their homes sit on. Knowledge of the risk would have changed everything, Sherry Cripps said. "We would have been going to the developer and saying, 'Hey, buy this back.'"

In a letter to Colorado Springs officials last week, state geologists urged the city to take more aggressive action than they have to monitor and assess the risk the Broadmoor golf course slide poses to homes, infrastructure and residents of the area.

Typically, the state's geologists serve in an advisory role, conducting studies of areas at risk of landslides and making nonbinding recommendations. But it is up to local governments that choose to work with them to decide whether and how development will occur.

A city spokeswoman acknowledged in an email that the city has known about the landslide risk near Cheyenne Mountain since 1996, but she added that city officials think the land is safe for development.

"We live in a mountainous community and therefore landslides are unfortunately an unavoidable risk," wrote Jamie Fabos. "However, these landslides have caused very little movement over many years and development can successfully take place on landslide susceptible areas if the appropriate mitigation measures are identified and followed."

The Denver Post obtained thousands of pages of documents related to the slide zone — including engineering studies, correspondence between city officials and the state and court testimony — from geologists who have studied the area for decades and through public-records requests to Colorado Springs.

Those documents and interviews show that a more cautious approach to development in the area could have prevented much of the property loss occurring now. Geologists warn that Colorado Springs' landslide issues, and losses for homeowners, could get worse.

Three homes on the federal buyout list have already been condemned, and of the 53 properties that have been assessed, 15 have dropped 50 or more percent in value, according to the county assessor.

(Severiano Galvan, The Denver Post)
Eighty-four homeowners across Colorado Springs have applied to the hazard mitigation grant program, the vast majority in the southwest part of the city. The city of Colorado Springs has applied for a $14 million federal grant, which would help it to cover the cost required to purchase qualified homes at their pre-damage value. If awarded, the federal grant would cover 75 percent of the cost, while a local government would provide the remaining 25 percent. The city of Colorado Springs has not committed to helping fund the remainder.

Owners of homes with no damage fear that values in city's most sought-after enclave, where houses range in price from half a million dollars to $2 million, will plummet. Many continue to spend hundreds of thousands of dollars fixing their properties, even while they wait to receive grant money.

Lt. Colonel James Branch, who lives a few blocks from the Cripps, is angered that the burden of bailing homeowners out will fall on the taxpayers. Although his home is not damaged, he applied for the buyout program as a precaution.
Because of this, he wants to know who is responsible for approving development in a landslide zone. In early April, Branch sent an email to the company that built his home asking for accountability.
To the untrained eye, the landslides are all but invisible.

"There are three that we know about, those are slower-moving rotational landslides, as opposed to this huge fast-moving rock avalanche," said Karen Berry, director of the Colorado Geological Survey.
The unstable zone covers 34 square miles. Some homeowners have measured localized landslides, and have found that they move about an inch a week, and sometimes an inch a day.

The area sits on a steeply tilted bedrock that extends in a narrow band along the mountain front. In places, it is covered with ancient landslide deposits, composed of earth and gravel, that can be many feet thick. The earth is stable as long as it does not have excessive moisture, or is not disturbed. But once water lubricates the earth above the bedrock — or development removes some land — the landslide can be activated.

After development and heavy spring rains in 1996, parts of the landslide began to move off Cheyenne Mountain, when it started buckling houses one at a time as it worked its way down to Fort Carson. In the mid-1990s, it broke a home in two in one day; in 1999, it destroyed 27 homes. Now, after a record-breaking rainfall in May 2015, the slide is moving again.
The current federal buyout program is the third since the slides began moving. In 1999, the federal government gave 75 percent of $6.6 million to help buy out 27 homes in southwestern Colorado Springs.

The landslide doesn't move as one mass — instead, sections will be triggered while others lay dormant. City planners have approved, without extensive study, construction of homes on dormant landslide areas that are next to active areas — a practice that geologists caution against.

In letters to city planners, state geologists have repeatedly urged builders to carefully study the area's geology, suggesting the safest places for homes or else suggesting that no homes be built at all.

"The fact that it is an ancient landslide does not mean that it can't be built on," said Jonathan Lovekin, a senior engineering geologist with the state. "While we advise avoidance of landslide deposits, where this isn't possible detailed analysis and investigation of the slide is recommended along with careful design, construction and ...full disclosure of the risks."
A city ordinance passed in 1996 requires that builders have a geological study of each subdivision before city planners approve the plans. In cases with extreme risk, the studies were sent to the state geologists for review, who sent back recommendations for building.

City officials say they view the recommendations as requirements, as laid out in the guidelines of their ordinance. But when it comes to making sure those recommendations are followed, the city relies on the builder to follow through, the city's spokeswoman said.

"The developer is responsible for following the recommendations of the engineers hired to evaluated the development," Fabos said. The city acts as an intermediary and passes comments between builders and the Colorado Geological Survey.
The lack of checks and balances in the city's ordinance has allowed homes to be built where they should not have been, and for the landslide risk to be overlooked, even as slides were damaging homes.
For instance, at least one home on the current buyout list is next to one for-sale lot and another home under construction. The Cripps' home was built on a landslide, although White specifically warned the city against building homes in certain areas on Broadmoor Bluffs Drive.

In years of working with engineers, White said, he has found that many geological hazards studies overlook the landslide risk, either by not mentioning it at all or declaring the ground stable simply because it hasn't moved in recent history.
Since it was first passed, the city's ordinance has been contested by many of the region's biggest developers, who lobbied to cut out the state's role in approving development. In 1998 a group of builders, including the Broadmoor's development arm, sent the city a letter arguing that state geological studies delayed progress and raised costs.
Tensions between geologists and developers aren't unusual in Colorado, White said, but Colorado Springs has been particularly divisive.

In meetings earlier this year, city employees and geologists discussed the possibility of updating the ordinance again.
"We are undergoing a validation process to better understand the landslide or landslides affecting our area, which may include further study," Fabos said. "We will use any new information to help evolve our development review process and examine if additional processes could be added to mitigation this issue."

The slide on the southwest side of the Broadmoor's South Golf Course is considered the most serious slide currently active in the area.

Two adjacent homeowners have applied for federal aid and state geologists have stepped in to evaluate the slide. That number might not represent all of the damaged homes, as some homeowners are paying to fix their homes.
The hotel has been battling the slide for two decades. During that time, it has built homes on nearby lots, and sections of the subdivision are too close to the slide, according to state geologists.

"They did pull some lots out, but they also continued to develop right on the edge of the head scarp," said Lovekin, referring to the landslide. "They still built too close to the edge of the landslide."

Following heavy rains in 1999, engineers warned the Broadmoor's development arm not to build homes on certain lots at that time due to landslide risk, but records show the homes were built a couple of years later.

State geologists warned the city and developers that building on some of these lots was extremely risky, and should not be done without extensive study of the landslide. "The site lies entirely within a historic landslide complex," White wrote in letter to the city in 1996. "Though no earth movements have been seen within the site, there has been substantial recent slide activity downslope, at the golf course."

He suggested that the neighborhood have limited irrigation, to prevent triggering another landslide, something that city planners said they couldn't enforce, according to email correspondence saved in the city's archives.

In 1997, an engineering firm studied geological hazards for the hotel's land development company. The study blamed irrigation for landslide issues, and said that watering led to reactivation of the historic landslide.

But last November the Broadmoor filed a notice of intent to sue Colorado Springs Utilities, blaming the latest slide on a ruptured pipe. The hotel's engineering firm claimed that the slide made nearly $14 million worth of nearby residential lots unbuildable.

Of the three neighborhoods now imperiled by an active landslide in southwest Colorado Springs, none have more complicated histories than that of the Broadmoor Bluffs Drive in the Broadmoor Glen South subdivision.
In 1996, a private engineering firm did a geological study for Gates Land Co., which owned the Broadmoor Bluffs properties at the time. The firm warned that building in the subdivision would place homes on unstable land. The state geologists who oversaw some of the city's development plans agreed.

White recommended the city only approve homes built as close as possible to the drive, a narrow ridge with landslides on either side. But the Cripps' home and possibly others were built as far away from the road as possible to take advantage of views.

There are cases in which homes were not built where geologists recommended against it.

The Cripps said the city initially rejected their plan setting the house from the road. Later the city relented, but officials never informed them about the landslide on their and their neighbors' properties, the Cripps said.

A couple of years after moving in, they noticed cracking around their home and a ruptured pipe, and the couple spent hundreds of thousands of dollars fixing the problems.

The Cripps hired a geologist, who recommended they plant devices around their property to measure movement. The Cripps said they assumed a ruptured pipe had been the cause of the problems.

Now, a landslide on the north side of the drive is carrying their home with it as it moves downhill. Door frames have snapped in half, floors undulate and dip, and the entire house is tipping down.

"If you drop something you chase it over to the north end," said Sherry Cripps.

The risks of building on Broadmoor Bluffs Drive were underplayed, geologists say. Years after White shared his concerns with building the area, he found that the engineering firm had changed its assessment of the subdivision. "Much of the strong wording, recommendations and considerations given to landslide susceptibility and warnings for development had been stricken" from the report, White said.

White no longer agreed with the firm's conclusions. But the development later was approved and construction began in 1998. Many of White's concerns, such as the setback of homes and studying the landslides, were overlooked.

John Himmelreich, the geologist who knocked on the Cripps' door, also was disturbed by the lack of disclosure to homeowners. In 2002, he testified that he quit his job with an engineering firm when he learned that some of the recommendations and warnings about landslide risks he made in the late 1990s were removed from geological studies before they were submitted to the city.

The case involved the Cripps' home, yet the couple say they were never informed about Himmelreich's testimony. The Cripps had sued their builder over structural issues with the home, but they did not know those issues were connected to landslides. Their lawsuit was settled out of court.

Himmelreich testified that he had revealed the landslide risks in the area to at least one development company that decided not to pursue the project.

But a couple of years later, Ron Delay, a well-known Colorado Springs developer, purchased the land. The state's geologists warned Delay and the city that certain lots would require special construction while others should not be built on at all.
The Cripps' home was one of the first to be completed in the subdivision, and it was two doors down from a home that Delay built for himself. As their neighbor, the Cripps knew the developer for years, but they said Delay never mentioned anything about a landslide risk.

Delay died in 2012, but his former home on Broadmoor Bluffs Drive was the first to be condemned when the landslide problems started last year.

Ryan Maye Handy is a freelance journalist and former reporter for The Gazette in Colorado Springs. She can be reached at ryanmhandy@gmail.com.

Homeowner Jim Millman stands in the cracked basement at his home in the Broadmoor Bluffs on April 11, 2016 in Colorado Springs, Colorado. He and some of his neighbors are among 200 homeowners who have applied for federal bailouts because their home is being eaten up by collapsing expansive soil that is part of an ancient and massive landslide area. (Helen H. Richardson, The Denver Post)

The owner of this website has made a commitment to accessibility and inclusion, please report any problems that you encounter using the contact form on this website. This site uses the WP ADA Compliance Check plugin to enhance accessibility.