By Mike Archer. With the horrors of the Washington State landslide still fresh in the minds of most in the Fraser Valley, some are looking at the many residential and commercial developments on the hillsides and mountainsides and wondering whether we are immune from the same sort of tragedy.Councillor Henry Braun raised the alarm bell at a recent council meeting over the structural viability of a proposed housing project on Sumas Mountain’s south slope.
“I cannot support a project that might put future residents at risk of landslides. The last one was in 1935 and, if you’ve been up there, that hillside appears to be moving.,” said Braun.
He was speaking at the February 17 Abbotsford Council meeting at which council turned down an application by a developer to build condo developments, partly over concerns with landslides.
The Estevan Court proposal would have necessitated rezoning the property from single-family residential to multi-family in order to allow for the townhomes but several councillors were also concerned with the dangerous slope.
That Hill Is Coming DownCouncillors John Smith and Henry Braun both spoke out against the proposed rezoning citing the dangerous slope on which the neighbourhood sits and the fact that, at the public hearing into the proposal, a large number of neighbours spoke against the changes it would mean to the value of their homes.
Smith even indicated he thought the council should never have approved the proposal.
Braun told council, “I cannot support a project thatmight put future residents at risk of landslides. The last one was in 1935 and, if you’ve been up there, that hillside appears to be moving.
Smith told council, I share Councillor Braun’s concerns regarding the slope and the risk. That is a very steep slope. Council should never have approved this.”
Councillor Moe Gill, “One of these days that hill is coming down.”
*With regard to the comments made by City Council, City Manager told Abbotsford Today, “We cannot comment specifically on their statements. However, we can note that Councilor Gill’s statement was reflecting on (or reiterating) comments from a previous Mayor of the City.”
Residents Protected By Approval Process
– Remedial Action, Covenants, Approving Officer
“One such report was completed by a Geotechnical Engineer who needed to review the various Geotechnical considerations of this specific subdivision, but also needed to consider the land adjacent to the subdivision. As such, the Geotechnical Engineer provided a positive review that required a number of remediation/engineering requirements for the subdivision to be proceeded with.
“Some of these considerations included remedial works at/on the actual face of the mountain as well as “engineered” rock fall mitigation works. Once these works were completed, the Geotechnical Engineer must sign off that the actual engineering requirements of the residential subdivision have been completed properly. It should be noted that the original geotechnical report was “peer reviewed” by a very senior Geotechnical Engineer at the request/requirement of the City. Finally, in order to ensure that any prospective property purchaser was well informed, the City required a Covenant be registered on title which would inform purchasers of the various geotechnical issues surround the development of their property(s).
“From a more general perspective, the Provincial legislation (Land Titles Act) requires that all Cities must appoint an “Approving Officer” that is responsible for exercising certain duties, including the approval of all subdivisions in the municipality. The Approving Officer has responsibilities that cannot be superseded by Council and/or any City staff (including the City Manager) with regard to their duties. Of even greater importance, the Approving Officer must protect the public interest in all their duties.
“As such, the Approving Officer must satisfy themselves that any subdivision, including the subdivisions on hillsides like Sumas Mountain, are approved in an appropriate manner. This includes ensuring that all appropriate reports from Registered Professions (like Geotechnical Engineers) are undertaken to a degree acceptable to them.
“Based on the foregoing, while Council may approve (or not) a rezoning application to approve/change a land use for a specific property(s), it is the responsibility of the Approving Officer to ensure that the subdivision meets the required standards.”
Studies On Sumas Mountain
A number of studies have been performed over the years on Sumas Mountain and what is known as the Huntingdon Formation.
The 1999 Sumas Huntingdon Study identified the fact that the upper and lower parts of the Formation were made up of separate kinds of deposits, with the lower portion being made up primarily of sand and gravel.
The Burnaby_Mountain_Geologic_Faults_-_BGC_Report revealed ” … thick glacial
and post-glacial sediments which overlie the area,” but that, “At present , there are no known active faults in the Lower Mainland.”
“However,” the report continued, “that does not mean there are no active faults. Recent work
in the U.S. has revealed active faults within 5 km of the border, and it is possible that given comparable research active faults could be found north of the border.”
Perhaps the most worrisome report comes out of the US as described in a 2008 Vancouver Sun story:
In 2008 the new Boulder Creek Fault was discovered under the Casacde Mountains jjust south of Abbotsford.
New Fault Line Under Sumas Mountain Discovered
“U.S. seismologists warn a shallow fault line near Abbotsford could cause an earthquake the size of a 2001 temblor that caused $2 billion in damage to the Seattle area.
New seismic-hazard maps released by the U.S. Geological Survey show the Boulder Creek fault 40 kilometres east of Bellingham running 11 kilometres lengthwise and 17 km across into B.C. near Abbotsford.
“It wouldn’t have a lot of impact in Bellingham, but would have a lot of consequences for our friends in B.C.,” Seattle seismologist Craig Weaver told the Bellingham Herald.
Other Published Research
- Brett Hollis Tallentine Gilley
BSc Simon Fraser University 1999
Conclusions Page 10
- Department of Mines and Technology
- Paleantology Sumas Mountain
- City of Abbotsford
- BGC Engineering
- Vancouver Sun 2008
- Geological Survey of Canada
- Dr Tracy Lyster
Cover Photo from Vancouvertrails.com