Credit 1.6: Managed Retreat
This credit applies when existing buildings can be moved inland to help prevent shoreline erosion and adapt to ongoing or predicted shoreline recession.
Moving buildings inland will avoid the need for shore protection and other negative impacts associated with managing erosion in the future.
Where this credit applies
This credit applies to any site where buildings are at risk from shoreline erosion. It applies to marine and freshwater shores, and particularly marine shores that are subject to long term sea level rise and shoreline recession.
Retreat should only be considered or recommended if the building in question can be moved to a location that is above the area affected by shoreline erosion/recession predicted to occur within 75 years or the life of the building, whichever is greater. Also, only consider retreat if the property is large enough to allow this move without compromising other legal setback requirements, or if the building can be relocated off the property.
This credit offers up to 10 base points* plus 3 bonus points.
|Move an existing major building** to a location that is above the area affected by shoreline erosion and recession predicted to occur within 75 years or the life of the building, whichever is greater.||
|Move an existing minor building*** to a location that is above the area affected by shoreline erosion and recession predicted to occur within 75 years or the life of the building, whichever is greater||
|Bonus (available once 1 or more base conditions have been met)||
|Add the effects of sea level rise into determining the relocation of a major or minor building.||
*10 points can be achieved for addressing both a major building and a minor building.
**Major building refers to a permanent house or dwelling.
***Minor building includes garage, boathouse, shed, etc.
How to proceed
To meet this credit requires:
A site plan that shows the original building footprint and the site to which the building has been or will be relocated. The relocation site must be landward of the area affected by projected erosion for 75 years or the life of the building, whichever is greater. General rules of thumb for an adequate distance are 35 ft (10 m) from the predicted receded OHWM/ NB or receded bluff/bank edge for low to moderately eroding sites, and 70 ft (20 m) for rapidly eroding sites;
To include climate change-induced sea level rise, determine what the projected SLR is for your area. For example, SLR of 0.5 m by 2050, 1.0 m by 2100 and 2.0 m by 2200 is predicted for most of the BC coast (Ausenco Sandwell, 2011). Determine how this will change the location of the OHWM over 75 years or life of the building (whichever is greater), and determine the relocation site accordingly.
Measurements of planned/existing building setbacks and the usable space available for moving the buildings back would have to be assessed and quantified from project drawings and also in the field. This involves simple linear measurements and does not require any special qualifications other than judging where suitable land is available.
Marine: An example of a house moved landward to adapt to shoreline conditions. (From MSDG 6-8).
For more information
Arlington Group Planning and Architecture Inc. et al. 2013. Sea Level Rise Primer: A Toolkit to build adaptive capacity on Canada’s south coasts. Go to http://www2.gov.bc.ca/ and enter “sea level rise adaptation primer” in the search box.
Ausenco Sandwell. January 2011. Climate Change Adaptation Guidelines for Sea Dikes and Coastal Flood Hazard Land Use. For BC Ministry of Environment. Go to http://www2.gov.bc.ca/ and enter “coastal flood hazard” in the search box.
Bornhold, B. 2008. Projected Sea Level Changes for British Columbia in the 21st Century. 12 pg. Go to http://www2.gov.bc.ca/ and enter “Bornhold sea level changes” in the search box.
New Zealand Ministry for the Environment, July 2008. Coastal Hazards and Climate Change: A Guidance Manual for Local Government in New Zealand http://www.mfe.govt.nz/publications/climate/coastal-hazards-climate-change-guidance-manual/
Nickel Brothers House Moving – http://www.nickelbros.com/
University of Washington Climate Impacts Group and Washington Department of Ecology. 2008. Sea level Rise in the Coastal Waters of Washington State. 11 pg. http://www.cses.washington.edu/db/pdf/moteetalslr579.pdf