The physical character of the City of North Vancouver is shaped by the creeks and ravines in its neighbourhoods, and the spectacular features of our mountainside community create challenges with regard to slope stability.
Landslides are caused when the stability of a slope changes from being in a stable to an unstable condition.
Unstable slopes can be caused by:
- groundwater pressure acting to destabilize the slope
- the weakening of a slope through saturation by heavy rains
- loss of vertical vegetation (eg trees and bushes)
- earthquakes adding loads to barely-stable slopes
- vibrations from machinery or traffic
- blasting
- earthwork which alters the shape of a slope, or which imposes new loads on an existing slope
- the removal of deep-rooted vegetation in shallow soils
- construction, agricultural, or forestry activities which change the amount of water in the soil
Steep Terrain
In 2008, the City of North Vancouver conducted a city-wide review of landslide risk following on from the experience gained during the study of land slide risk along the east bank of Mosquito Creek. The Preliminary Geotechnical Study prepared by BGC Engineering Inc dated April 24, 2009 identified 18 properties (in addition to the 8 properties on the east side of Mosquito Creek) that warranted detailed investigations. Presentation materials and Meeting Notes from the Open House held June 24, 2009 are provided below.
As recommended in the 2009 BGC Engineering report, properties identified as having a "high" or higher partial risk of being damaged by a landslide were assessed. The properties investigated include those listed in the BGC report plus two additional properties identified during field investigations. A Phase 2 Geotechnical Stability Study - Detailed Risk Analysis dated December 2011 - was completed by GES Geotech and copies of the report were issued to the affected property owners. An Open House was held on January 26th, 2012 to discuss the report and follow up meetings were offered to affected individuals.