With homeowners tearfully locking the doors to their homes, likely for the last time, a trove of documents is shining a light on the history of the sinkhole-riddled area on a picturesque waterfront stretch of Sechelt.
Displaced resident Chris Moradian insists “the residents of Seawtatch were kept in the dark and not provided with the prudent facts,” but the District of Sechelt insists “All of the engineering reports have been provided to the Seawatch residents, and many have also been posted on the District of Sechelt web site.”
CTV News has been poring over those documents since the city directed us to a collection of them Friday. Here’s a summary of the key reports, depicting a changing perspective of this issues underlying this corner of the Sunshine Coast.
1992 - The earliest report on the city’s website from Terra Engineering found “the property as a whole to be well suited to the type of residential development proposed” and that “if care is undertaken to prevent post-development storm water runoff from reaching unprotected slopes, the long term erosion potential of the surface is minimal.” The final page reads: “There is no particular natural hazards of this site,” but the report also recommends more testing.
1993 – Under a section titled “Geological Hazards,” a Golder Associates report found “various types of existing and potential natural hazard which can affect development” and goes on to say “the assigning of probability levels to specific hazard events, or a series of events, can only be achieved by carrying out more detailed geotechnical and hydrological studies to determine appropriate hazard probability/magnitude relationships.”
1998 – A development application was made, but the city notes it was “left uncompleted” in that year.
2004 – Geotactics Engineering prepared a report for the developer after one day on site and “an earlier report by Geotek Designs for part of the site was made available as background information.” The report concluded that “the probability of occurrence of geotechnical hazards is estimated to be less than 10 percent in 50 years,” but it also noted “several test pits should be excavated around the property to verify the subsurface conditions here” and that “each of the lots in Phase 1 should have an individual geotechnical assessment prior to final design and construction.”
2005 –Sechelt district staff reported that in February, test pits were excavated to verify conditions at the “Shores” development. The report recommended council issue a development permit provided there are protections for banks and the shoreline, as well as “Registration of a Covenant on each of the lots in Phase 1 stating that a geotechnical assessment is required prior to the issuing of a Building Permit establishing building setbacks, storm runoff disposal and foundation construction specifications.”
2006 – Geotactics Engineering wrote a follow-up report dated April 2006, mentioning the formation of four sink holes in the proposed subdivision area, “one of which was 10 feet in diameter and about eight feet deep.” The report reads “On further investigation, the occurrence of sink holes in this area was found to be more common than previously believed” in other parts of Sechelt. Nonetheless, the report concluded with the identical line from 2004: “The probability of occurrence of geotechnical hazards is estimated to be less than 10 per cent in 50 years.” A supplementary addition the following month claims “until a soil collapse occurs, the presence of a (potential) sink hole is generally undetectable. The occurrence is random.” The city imposes as “restrictive covenant against title” to the area, which includes the Geotactics report.
2007 – Construction begins.
2008 – Thurber Engineering assessed the construction of retaining walls and slopes, but addressed the sink hole issue, noting the addition of rounded gravel to the existing sand could be an issue: “If water ingress occurs into the sand due to, for example, excessive lawn watering or broken water service, then any seepage through the sand that exits where there is rounded gravel backfill could cause internal erosion and piping with resultant formation of a sinkhole at the crest of the slope.”
2012 – The first sinkhole to affect a home at The Shore manifests. Thurber Engineering found a spring developed in May of that year, with a sinkhole collapsing without warning June 1 and “Additionally, there have been several instances of slope instability during and after construction.” But their conclusion was that “Given the low potential for internal erosion of the soils present at the site, we believe the most likely cause of the sinkholes is collapse of piping cavities.”
The city tried to address the issue by filling the hole with gravel while hiring consultants to assess the area with ground penetrating radar, land surveying equipment and aerial mapping. Thurber mentions several reports they reviewed but were not made public, including a 1997 report by Geotek Designs they quote as saying: “’There are no indications of any threat of landslide.’ Geotek also states that ‘the land can safely be used for the use intended.’”
2013 – The District of Sechelt announces it has accepted a settlement offer of $75,000 from Concordia Seawatch toward the community’s costs to investigate the sinkhole issue after council had approved “remedial action requirements.”
2015 – Another sinkhole forms, which renders a home uninhabitable; a lawsuit would follow. Thurber Engineering warns “identified voids and loose zones could develop into sinkholes in the future if measures ear not taken to address the processes which contribute to sinkhole development.” Urban Systems provides three solutions for dealing with the ongoing issue, the most comprehensive coming in at just shy of $10 million. Urban Systems suggests a fourth option: “the closure of the subdivision, either partially or fully, and abandonment of infrastructure.”
The District of Sechelt meets with Seawatch residents and tells them it won’t pay for a multi-million dollar solution, which doesn’t come with a guarantee of success and would require a 8.5 per cent property tax increase on all Sechelt residents to finance.
Dec. 25, 2018 – Another sinkhole opens, 25 metres deep and four metres wide. Thurber Engineering suggests closing Seawatch Lane to vehicle traffic pending geotechnical assessment with warnings of the sinkhole hazard in the area. Most chillingly, Thurber warns “Future sinkholes could damage existing infrastructure such as underground utilities, raods or sidewalks, or private property including buildings and retaining walls. Injry or even death is a possible consequence.”
February 2019 – The Seawatch subdivision is put on evacution alert and begin packing their things.
Feb. 15, 2019 – The District of Sechelt declares a local state of emergency and the evacuation order is executed at 1 p.m. The same day, Ron Davis emails this statement to CTV News: “The developer of the Seawatch housing development, Concordia Seawatch Ltd., has great concern and compassion for the homeowners and families that are now being required to leave their homes. As the developer and others are currently involved in civil litigation relating to the Seawatch Development, we are not providing further comment at this time.”
2020 – A trial claiming damages against the District of Sechelt and Concordia is slated to begin, stemming from a 2015 sinkhole.