Fact Sheet: 2007 Landslide
At Freedom Ridge Condominiums in Cold Lake, Alberta.
(912 2nd Avenue)
The following information represents my own research and observations. It does not
necessarily represent the views or opinions of Condominium Corporation 002-4982, the condominium board or other owners. It is offered
solely to help the current owners and future purchasers understand the circumstances leading to and
the final resolution of the 2007 land slide (slippage). Once people understand all the facts, they can
be confident that their homes are safe and their investment is secure now and in the future.
The landslide that occurred in June 2007 on the City Owned environmental reserve behind the condominiums known as Freedom Ridge was a direct result of:
Failure of the builder to establish adequate site drainage.
Failure of the City & building inspector to ensure compliance with existing bylaws (drainage).
An incompetent contractor who installed sub-surface drains in a misguided attempt to establish proper site drainage.
These issues have been fully rectified by the Condominium Corporation and the City has repaired the slide area on their environmental reserve. There is absolutely no risk of a future recurrence of the landslide and the land upon which the condominiums sit is as stable as any other building site in the City.
Read on for the rest of the story...........................................................
Background
In 1993, Mr. Mark Graham proposed the construction of the Lindsay Point Apartments on the former site of the John Neil Hospital in Cold Lake (Lot A, Block 5, Plan 515E0). He commissioned a Geotechnical Investigation by HBT AGRA Limited of Lloydminster, Alberta. The resulting geotechnical report was issued June 9, 1993.
A study of the soil profile and groundwater conditions was conducted using a number of test holes to collect core samples and measure ground water levels.
The report made specific design recommendations and comments for the proposed construction of the 3 - 4 story apartment buildings.
In no way does it suggest that the area is unstable, unsafe or at risk of land slides as suggested by a
lawsuit filed on June 18, 2009 with the Court of Queens Bench in Edmonton.
The only item that addressed slope stability was a recommendation for the development to be set back from the existing top of bank which is approximately 30 meters from the waters edge.
Because the 3 proposed 4 story apartment buildings had a footprint of 500 square meters each, and considering the setback requirements mentioned above, there was not sufficient room to build the apartment buildings and provide a parking area. Therefore, the project did not proceeded.
In 1999 or 2000, Value Master Homes conceived the idea for an adults only, maintenance free condominium to be built overlooking Cold Lake on the same site. They purchased the land and entered into a development agreement with the Town of Cold Lake on September 25, 2000. A copy of this development agreement can be viewed at http://www.visualsc.com/Dev_agreement.pdf.
The condominium plan was registered with Alberta Land Titles on December 28, 2000 and Condominium Corporation 002-4982 was created (Freedom Ridge is not a legal entity). The condominium plan consists of 12 bare land units plus common area. The bare land units are owned by the individuals in fee simple. In other words, each owner has a title to their land and it is not part of the common property of the corporation. However, through its bylaws the condominium corporation controls and administers the owners lands (excluding buildings) as managed property.
In early 2001, Value Master Homes applied to the Town of Cold Lake for a development permit and other building permits and commenced construction of the first 6 of the 12 units (1, 2, 7, 8, 9 & 12). It appears that they complied with the recommendations in the 1993 Geotechnical Report including the use of properly designed spread footings and maintaining the required setbacks.
Analysis of the Failure - How did things go so wrong??
To understand the root cause of the land slide, it is necessary to go back to the beginning of the project and understand how a number of relatively minor deficiencies and poor decisions interacted to cause a serious and costly incident.
Poor design, lack of supervision and a failure of the building inspector for the Town of Cold Lake resulted in serious drainage issues within the project.
Although the original development agreement between the developer and the Town clearly required a Lot Grading Plan (see Section A2.6) to be submitted, it has never been verified that the Town received it. If in fact it did exist, it is clear that there was a lack of attention given to the planning of the final elevations of the units and the roadway. Generally throughout the project, the developer failed to meet the requirements of Section A2.6.1 that defines the required grades to ensure adequate surface drainage.
It does not appear that the Town of Cold Lake building inspector ensured that the Lot Grading Plan was submitted and approved by the Town Engineer nor that the required permits were issued. Clearly, the building inspector did not observe, identify and/or report the problem on the job site so it could be rectified before final grading and landscaping was complete.
In 2006, the condominium board developed a plan to correct the drainage deficiencies
After 5 years, the owners pressured the board to fix the problems. In a few isolated cases, owners were seeing leakage into their basements. However, many owners were observing that sump pumps were operating almost continuously and although they did not see actual leakage into the basement, there was a justifiable fear that the sump pump might fail resulting in serious flooding.
As it was the mandate of the board to manage the project for the benefit of all the owners, they began to develop a plan to correct the drainage issues. Initially, they contacted a reputable landscape company who inspected the site and claimed that the original landscaping done by A.N.D. Bobcat Services on behalf of Value Master Homes was not done correctly and was the cause of the issues the owners were reporting. The provided an estimate of $30,000.00 to re-landscape the project.
The board also approached Cat Landscaping to ask if they could offer an alternative. He recommended the installation of weeping tile to direct the water from the eaves troughs and sump pumps away from the buildings. His estimate for the work was less than $10,000.00. In approving this plan, the board failed to exercise due diligence to ensure that the alternative design would work and that Cat Landscaping had the knowledge, experience and capability to do the work. The board never asked the question as to why Cat Landscaping could provide a solution for less than 1/3rd of what the first company had estimated. They also did not confirm that Cat Landscaping was licensed to work in Cold Lake and would obtain the necessary permits from the City of Cold Lake. Finally, the board failed to approve the expenditure at a duly convened meeting of the board.
After receiving the go-ahead from the board, Cat Landscaping commenced work. He installed weeping tile in a gravel filled trench approximately 6-inches below ground level. A necessary and critical non-permeable liner was NOT installed. Laterals from this weeping tile collected water from the eaves trough down comers and the sump pumps. Weeping tile within a gravel filled trench is also known as a French Drain. The following sketch shows the locations of the drains as installed:
Although similar in construction, the design of each French Drain differed in where the collected water was intended to be directed.
The drain between units 11 & 12 attempted to direct the water onto the frontage paralleling 2nd Avenue.
The drain between units 8 & 9 attempted to direct the water onto the environmental reserve.
Between units 6 & 7, Cat Landscaping dug an approximately 15 foot deep accumulation pit which was filled with gravel. The drain was connected to this pit where it would then disperse into the sub-soils.
The drain between units 5 & 6 was not directed anywhere. The obvious intent was to allow the collected water to penetrate into the sub-soil.
The drain between units 2 & 3 attempted to direct the water onto the environmental reserve at the "top of bank" so that it would run down the slope to the lake.
With the French Drains installed, the condominium board believed the problem was solved. However, a technical review of the design and implementation of Cat Landscaping plan clearly shows that it was seriously flawed and was only a matter of time and circumstances before a serious land slide would occur. It was not a case of "IF", but rather "WHEN" and that was to come within less than a year!!!
The problem with the design begins with how the weeping tile was installed. There are 2 types of French Drain.
Type 1 is intended to drain surface water to a location away from building foundations. It consists of a shallow trench lined with a non-permeable liner to prevent water leaving the trench once it enters. A layer of gravel is laid in the trench and then a slotted collector pipe (weeping tile) is placed on top of the gravel. Additional gravel is then added to fill the trench. A shallow layer of top soil can optionally be added to finish off the area provided that water can still drain through into the trench.
Type 2 is intended to drain sub surface water to lower the water table around the building foundations. Like type 1, it consists of a shallow gravel filled trench with a collector pipe. The trench is placed well below ground surface at an elevation to control the maximum water table level. It also differs from type 1 in that it does not have a non-permeable liner. This allows water to enter the gravel pack and collector pipe unrestrained and then be directed away from the foundations.
Click on the image below for a sketch illustrating the differences between the two:
Cat Landscaping did not have the knowledge, experience or skill to carry out the work.
He installed a type 2 drain intended for installation below the water table. It should have been a type 1 drain which would have included a non-permeable liner. Without this liner, the water collected by the drain was evenly distributed within the sub-soils forcing water to over-saturate the ground resulting in a dangerous condition that weakened the strength of the soil and directly led to the failure.
He actually had two different concepts within his design. The first was to drain the water away (units 2, 3, 8, 9, 11 & 13). However, without the critical non-permeable liner installed, the water never had a chance to actually reach the discharge point before it dispersed into the sub-soils. Secondly, on the other units (4, 5, 6 & 8) he clearly intended for the water to be forced into the sub-soils as there was no actual discharge point.
By coincidence, myself and another owner happened to inspect the areas around the drains just a few days prior to the slide during heavy rains. We observed that although there were large volumes of water being directed to the French Drains from the eaves troughs and sump pumps, there was no water flowing out of the drain discharges on the environmental reserve. This clearly confirms that the water had to be flowing into the sub-soil and saturating the ground all around the foundations and out at least partially into the environmental reserve. I also observed that my sump pump was working continuously which I had never observed prior to the installation of the drains even during similar rainstorms.
The following sketch shows the drains as they were installed between units 2 & 3 near where the slide occurred. Note that without the non-permeable liner installed, the collected water is free to filter down in the soil around the foundation. This water lubricated the interface between the clay and sand lens that was present, seriously weakening it and setting up just the right conditions for the slide.
The following picture shows the weeping tile laid in the gravel trench.
June 27, 2007 - Following several days of heavy rain, the soils reached the failure point and a section of land failed creating a land slide. The slide DID NOT happen on the Freedom Ridge Property, but rather on the environmental reserve between the project and Cold Lake.
The following picture was taken only a few hours after the slide occurred and I believe it is the most compelling illustration of how the installed French Drain caused the failure. Note that at the apex of the failure area, the broken French Drain can clearly be seen. The edge of the failure area moves outward uniformly on either side of the drain. Also, note that the failure area remained level and dropped straight downward about 3 feet. This is clearly indicative of a layer of sub-soil becoming saturated with water and then being washed outward down the bank allowing the surface layer above to drop straight down. It is obvious that this was not due to erosion as may have occurred if the water had actually been directed over the slope instead of into the sub-soil.
Over a few days, the slide continued to move downward. However, it remained mainly on the environmental reserve and did not continue onto the condominium lands except for some minor sloughing. After about 3 days, all movement stopped and there was absolutely no impact on the building foundations. After this initial movement, the slide area has remained stable for the past 3 years.
How did things get back on track?
Personally, I am very appreciative of the great response by the City of Cold Lake (Special thanks to development officer Treena Lane). Because the slide actually occurred on the environmental reserve area owned by the City and not the condominium lands, they very quickly responded by engaging UMA Engineering, a geotechnical engineering company to carry out a study of the slide area with the intent to understand the cause and recommend an effective long term repair.
During the summer and fall of 2007, UMA engineering drilled a number of test wells and installed standpipe piezometers to collect core samples, monitor ground water levels and detect further movement of the sub-soils.
In February 2008, they issued a draft report. Following is an excerpt:
UMA Engineering continued their work over the winter and spring and issued their final report in June 2008. This report expanded on the failure mechanism (slope saturation) and proposed a number of option for remediating the site.
In 2009, the condo board initiated a project to remove all sub surface French Drains from the project.
All drains with the exception of the one between units 2 & 3 were removed. This single drain was not removed pending the proposed work to repair the slide area by the City. Once the work is complete, it will also be removed.
The areas between the units where the drains were removed was re-landscaped by Northern Lights Landscaping to establish effective drainage patterns. This was effectively what should have been done in 2006.
In June 2010, the City of Cold Lake commenced slide remediation work to permanently repair the slide area and prevent future failures.
The remediation plan is well engineered and will provide a permanent repair. The entire section of environmental reserve to the lake shore will be removed and then built back up with engineered materials. The following is a cross section showing the different materials and placement. When completed, it is guaranteed to provide an extremely stable slope.
In conjunction with this remediation work, the owners and condominium board entered into an access agreement with the city that will ensure that the city can oversee any future changes to the landscaping or drainage of the condominium project that may have an impact on the future stability of the slope. This will guarantee the slope stability into the future.
The following pictures show the extent of the remediation work. As can be seen, the soil right down to the lakeshore has been removed. The company doing the work is skilled and competent and is clearly following the intended design
Is a condominium here a safe investment?
Every person must rely on their own judgement to decide if their existing investment is secure or if they are considering an investment here. I have to the best of my ability attempted to document all the relative facts surrounding the land slide to understand the root cause, what has been done to correct it and what the prognosis for the future is.
It is my PERSONAL opinion that the Condominiums are not at risk from a future slide because:
I can attribute the root cause to a known set of problems/causes. I do not believe there are any factors that have not been identified and given consideration.
I have verified that the drains which in MY OPINION were the direct cause of the slide have been removed and that the City has taken steps such that future owners or condominium boards can not repeat the same mistake.
I have personally witnessed that the required repairs to the slide area are being made as designed and that the company who developed that design is competent.
I would feel comfortable in recommending to my friends and family that they purchase a unit here.
