Policy Approaches for Natural Hazards


Policy Approaches for Natural Hazards


POLICY APPROACHES FOR NATURAL HAZARDS
(Provincial Policy Statement, 3.1)

Three portions of the "areas of Provincial Interest" have been identified as having unacceptable risks to life and property, and development is not permitted. They are:

  • defined portions of the dynamic beach
  • defined portions of the one hundred year flood level along connecting channels
  • a floodway

Development and site alteration may be considered in the remaining portions, provided that all of the following can be achieved:

  • The hazards can be safely addressed
  • Development and site alteration is carried out in accordance with established standards and procedures, including floodproofing, protection works, and access
  • New hazards are not created and existing hazards are not aggravated
  • No adverse environmental effects will result
  • Vehicles and people have a way of safely entering and exiting the area during times of flooding, erosion and other emergencies
  • Development does not include institutional uses or essential emergency services or the disposal, manufacture, treatment or storage of hazardous substances
  • The interest and intent of other laws and policies addressing the same area are not compromised (fish habitat, wetlands…) which may not consider development within these areas to be appropriate or acceptable
AREA OF PROVINCIAL INTEREST
POLICY APPROACH
NVCA WATERSHED
Hazardous Lands:

Great Lakes - St. Lawrence River System

Large Inland Lakes
The area of provincial interest is based on the furthest landward limit of:

a) flooding hazards involving the combined influence of lake levels (100-year level),

PLUS
a flood allowance involving wave uprush and other water related hazards. (15m on the Great Lakes)

b) dynamic beach hazards involving the combined influence of (a) PLUS a dynamic beach allowance. (30m on the Great Lakes, or 10m on large inland lakes)

c) erosion hazards involving the combined influence of (two step process)

Step 1:

Select one of a stable slope (3:1) PLUS recession rate allowance; OR Stable slope (3:1) PLUS erosion allowance (30m on the Great Lakes)

Step 2:
Whichever is the greater of step 1, OR an erosion allowance measured from the first lakeward break in slope
100-Year peak instantaneous water level is 178.0 meters (G.S.C.D.)

Wave uprush is 15m or an elevation of 178.3 meters

Dynamic beach allowance is 30m

Stable slope (3:1) and site specific inspection

In general, recession rate information is not available

Erosion allowance is 30m
     
Hazardous Lands:

River and Stream Systems

The area of provincial interest is based on the furthest landward limit of:

a) flooding hazards, greater of the 100 year flood event, storm centered event, or observed flood event

b) erosion hazards

Confined systems and terrain-dependant systems (consisting of cohesive materials) involving the combined influence of a toe erosion allowance OR 100 times the annual recession rate PLUS a stable slope allowance (3:1) PLUS an erosion access allowance (6m)

Unconfined systems and terrain-dependant systems (consisting of cohesionless materials) involving the combined influence of the flooding hazard limit OR meander belt allowance, PLUS
an erosion access allowance (6m)

Greater of the Timmins Storm (1961) or 100-year flood

In general, annual recession rate information is not available

Stable slope (3:1) and site specific inspection

Erosion access allowance is 6m

Meander belt allowance is site specific

Toe Erosion allowance is 100-year design based on 25 years of data on annual recession rates, or generally 15m from the toe of the waterway or base of the valley wall. Toe erosion is site specific.

     
Hazardous Sites

Unstable soils
Unstable bedrock

An area of provincial interest based on studies using accepted geotechnical and engineering principles and practices addressing toe erosion, slope stability, soil structure and bedrock material Site specific

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