What is happening with urban earthquake disaster planning in Nanaimo? Nanaimo residents are being told that the Lower and Middle Colliery Dams would be too unsafe during a large earthquake and must be removed, yet there are examples around the City of lax safety standards.
Pictured above is a new housing development on a steep slope overlooking Hammond Bay Road.
Three potential problems with this development:
- a torrential rain could bring down a river of mud onto Hammond Bay Road
- an earthquake could cause these houses to fall onto the road and block access
- Hammond Bay Road is the main disaster emergency route for this area which could become impassable
Has a geotechnical study been done on the stability of this slope? Are the concrete footings at the base of the slope adequate? What earthquake standards have been met?
The Colliery Dams have survived several earthquakes since they were constructed in 1910. Yet for some unknown reason this Colliery Dam project is being fast tracked at a record pace.
Other dams in the area appear to be off the radar. There are several dams which have not had any safety inspections:
- Reservoir #1, never done
- Jump Creek, never done
- Harewood & Witchcraft Lakes, not available
A comparison between Westwood Lake and Colliery Dams reveals more inconsistent data.
The 2004 Westwood Dam study used a 1-dimensional river modeling program. In comparison, the 2012 Chase River study used a 2-dimensional model.
As a result, Westwood Dam received a $500,000 fix in 2008 whereas the Colliery Dams’ removal could cost taxpayers tens of millions.
Why are there so many earthquake disaster standards being applied around the City of Nanaimo?
