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Consolidated: July 17, 2018
City of Chilliwack
Bylaw No. 4519
A bylaw to designate land as Floodplain and make provisions in relation to flood control,
flood hazard management and development of land that is subject to flooding or erosion.
__________________________________________________________________________
WHEREAS Council is authorized under the Local Government Act (Section 524) to enact a
bylaw to designate land as Floodplain and to make regulations in relation to flood control, flood
hazard management and development of land that is subject to flooding;
AND WHEREAS Council has considered the Flood Hazard Area Land Use Management
Guidelines published by the Province of British Columbia in May 2004, as amended, under
authority of the Environmental Management Act;
AND WHEREAS Council has considered the Professional Practice Guidelines - Legislated
Flood Assessments in a Changing Climate in BC, commissioned by the Ministry of Forests,
Lands and Natural Resource Operations and adopted in June 2012 by Engineers and
Geoscientists British Columbia Council under authority of the Engineers and Geoscientists Act;
AND WHEREAS the requirements of this bylaw were established with the assistance of
Qualified Professionals.
NOW THEREFORE the Council of the City of Chilliwack enacts as follows:
1.
This bylaw may be cited as "Floodplain Regulation Bylaw 2018, No. 4519".
2.
"Floodplain Regulation Bylaw 2004, No. 3080" and amendments thereto are hereby
repealed.
BYLAW OUTLINE AND SCHEDULES
3.
This bylaw covers:
-
Definitions (Section 4)
-
Designation of Floodplain Areas (Section 5)
-
Flood Protection Requirements (Sections 6 to 17)
-
General Exemptions (Sections 18 to 20)
-
Building Size Exemptions (Section 21)
-
Residential and Institutional Uses Permitted Below a FCL (Section 22)
-
Site Specific Application (Section 23)
-
Inspections, Offences, Penalties and Severability (Sections 24 to 27)
The following Schedules constitute part of the Bylaw:
Schedule A - Map of Floodplain Areas
Schedule B - Guidelines for Site Specific Application by a Qualified Professional
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 2
Consolidated: July 17, 2018
DEFINITIONS
4.
In this Bylaw:
"Alluvial Fan" means an accumulation of sediment where a steep stream channel flows
out onto a valley floor of reduced gradient, often fan-like in shape, subject to
further additions of sediment;
"Approving Officer" means the official who is appointed under the Land Title Act;
"Covenant" means a Covenant registered on title of land under the Land Title Act,
absolving the City of Chilliwack of any liability with respect to the flooding of the
property or flood damage to land, structures and contents thereof;
"Crawl Space" means an area located in part or entirely below the Flood Construction
Level having a maximum height from floor to ceiling of 1.5 m;
"Debris Flow" means the rapid downslope movement descending steep pre-existing
drainage channels of water-saturated soil and debris;
"Design Flood" means a flood equal in magnitude to the 1894 flood of record with
respect to the Fraser River OR a flood, which may occur in any given year, of
such magnitude as to equal a flood having a 200-year recurrence interval, based
on frequency analysis of unregulated historic flood records with respect to the
Chilliwack River, Vedder River and Vedder Canal;
"Design Flood Level" means the observed or calculated elevation for the Design Flood
and is used in the calculation of the Flood Construction Level;
"EGBC" means Engineers and Geoscientists British Columbia;
"Flood Construction Level (FCL)" means the Flood Construction Levels as indicated on
Schedule "A", attached hereto and forming part of this Bylaw;
"Floodplain" means the area shown on Schedule "A", attached hereto and forming part of
this Bylaw;
"Floodproofing" means the alteration of land or buildings to reduce flood damage and
includes the use of building setbacks from water bodies to maintain a floodway
and to allow for potential erosion. Floodproofing may be achieved by either, or a
combination of the following:
-
building on structural fill, provided such fill does not interfere with flood
flows of the watercourse, and is adequately protected against floodwater
erosion and scour;
-
building raised by foundation walls, columns or piles;
"Freeboard" means a vertical distance added to the actual calculated flood level to
accommodate uncertainties (hydraulic and hydrologic variable), potential for
waves, surges, and other natural phenomena;
"Geodetic Survey of Canada (GSC)" means the measurement of height in reference to the
coastal mean sea level for North America pursuant to an agreement between the
United States of America and Canada.
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 3
Consolidated: July 17, 2018
"Habitable Area" means any room or space within a building or structure that is or can be
used for human occupancy, assembly or Institutional Use, commercial sales, or
storage of goods, possessions or equipment (including furnaces) which would be
subject to damage if flooded;
"Inspector of Dikes" means a provincial employee appointed under the Dike
Maintenance Act with the statutory authority to oversee maintenance of dikes by
diking authorities, set diking standards and approve changes to existing dikes and
new dikes;
"Institutional Use" means a use providing for public functions and includes federal,
provincial, regional and municipal offices, schools, churches, colleges, hospitals,
community centres, libraries, museums, jails, courts of law and similar facilities;
and specifically excludes public storage and works yards, and public utility uses;
"Manufactured Home" means a structure manufactured as a unit, intended to be occupied
in a place other than at its manufacture, and designed as a dwelling unit, and
includes mobile homes, and specifically excludes Recreation Vehicles;
"Natural Boundary" means the visible high watermark of any lake, river, stream, or other
body of water where the presence and action of the water are so common and
usual and so long continued in all ordinary years as to mark upon the soil of the
bed of the lake, river, stream or other body of water a character distinct from that
of the banks thereof, in respect to vegetation, as well as in respect to the nature of
the soil itself;
"Natural Ground Elevation" means the average of the undisturbed ground elevations at
the four corners of the proposed building site;
"Non-Conforming" means any existing building located on flood prone land that does not
meet Floodproofing requirements set out in any pertinent bylaw, regulation or
Covenant;
"Pad" means a compacted gravel, paved or concrete surface on which blocks, posts,
runners or strip footings are placed for the purpose of supporting a Manufactured
Home or unit;
"Ponding Elevation" means the water surface elevation as controlled by the lowest
ground or road elevation of the area, which would act as the outlet to that area, if
a storm runoff exceeds the capacity of culverts or other in-ground drainage works;
"Professional Engineer" means a person who is registered or licensed as a Professional
Engineer under the provisions of the Engineers and Geoscientists Act;
"Professional Geoscientist" means a person who is registered or licensed as a
Professional Geoscientist under the provisions of the Engineers and Geoscientists
Act;
"Provincial Guidelines" means the Flood Hazard Area Land Use Management
Guidelines, Ministry of Water, Land and Air Protection, dated May 2004 (updated
August 17, 2011), in relation to flood control, flood hazard management and
development of land that is subject to flooding in the Province of British
Columbia, and Professional Practice Guidelines - Legislated Flood Assessments
in a Changing Climate in BC commissioned by the Ministry of Forests, Lands and
Natural Resource Operations, dated June 2012, as amended from time to time;
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 4
Consolidated: July 17, 2018
"Qualified Professional" means a Professional Engineer, Professional Geoscientist,
licensee, including limited licensees with the appropriate level of education,
training and experience to conduct flood assessments and licensed to practice by
EGBC;
"Recreation Use" means a use providing for indoor or outdoor recreation and includes
parks, playgrounds, and sports facilities;
"Recreation Vehicle" means any structure, trailer or vehicle used or designed to be used
for living or sleeping purposes and which is designed or intended to be mobile on
land, whether or not self-propelled;
"Standard Dike" means a dike considered by the Inspector of Dikes to meet minimum
provincial standards including: design and construction to contain the Design
Flood; design and construction completed under the supervision of a Qualified
Professional; an effective dike management and maintenance program by a local
diking authority; and legal access;
"Training Works" means any wall, dike or protective structure used to prevent a stream
from leaving its channel at a given location. This includes any Debris Flow
training structures including basins, trash racks, or other works;
"Watercourse" means any natural or man-made depression with well-defined banks and a
bed 0.6 m or more below the surrounding land serving to give direction to a
current of water at least 6 months of the year or having a drainage area of 2 square
kilometres or more upstream of the point of consideration.
DESIGNATION OF FLOODPLAIN AREAS
5.
The following areas of the City of Chilliwack are designated as Floodplain:
(1)
the Floodplains of the Fraser River, Chilliwack River, Vedder River and Vedder
Canal as shown on Schedule "A" attached hereto and forming part of this Bylaw;
and,
(2)
the Alluvial Fans and Floodplains of several creeks adjacent to the Fraser Valley
as shown on Schedule "A", attached hereto and forming part of this Bylaw.
FLOOD PROTECTION REQUIREMENTS
Setback Requirements
6.
Unless specified elsewhere in this Bylaw, no building or part of a building for which
Floodproofing is required shall be constructed, reconstructed, moved or extended, nor
shall any Manufactured Home or unit be located within the minimum setback from a
Watercourse, body of water or dike as specified below:
(1)
60 m of the Natural Boundary of the Fraser River;
(2)
75 m of the Natural Boundary of the Vedder River;
(3)
30 m of the Natural Boundary of the Chilliwack River and Vedder Canal;
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 5
Consolidated: July 17, 2018
FLOOD PROTECTION REQUIREMENTS (continued)
Setback Requirements (continued)
(4)
15 m of the Natural Boundary of any other Watercourse or the edge of a bluff,
subject to erosion or 3 times the height of the bluff (as measured vertically from
the toe to top of bluff), whichever is greater;
(5)
7.5 m of the Natural Boundary of a lake, swamp, pond or drainage ditch;
(6)
10 m of any structure for flood protection or seepage control or any dike right of
way.
7.
No landfill or structural support required to support a floor system or Pad, shall be
constructed, reconstructed, moved, extended or located within the Floodplain setback
specified in Section 6 of this Bylaw.
Elevation Requirements for Areas Protected by a Standard Dike
8.
Within areas protected by a Standard Dike, unless specified elsewhere in this Bylaw, no
building or any part of a building, Manufactured Home or unit, shall be constructed,
reconstructed, moved or extended with the underside of a wooden floor system or top of
a concrete foundation of any Habitable Area, nor shall any Pad be located lower than
(whichever elevation is greater):
(1)
the applicable FCL for the Fraser River, Chilliwack River, Vedder River or
Vedder Canal as indicated on Schedule "A", attached hereto and forming part of
this Bylaw, plus 0.6 m Freeboard;
(2)
1.5 m above the boundary of any other natural watercourse;
(3)
0.6 m above the top of bank of any drainage ditch;
(4)
0.3 m above the crown of the adjacent road.
The 0.6 m Freeboard requirement may be waived on the condition that the owner
registers a Covenant against the title and also provides a Qualified Professional's report
indicating that the property may be safely used for the intended purpose.
9.
Within areas protected by a Standard Dike, a dwelling unit or other building thereon may
be constructed with the underside of a wooden floor system or the top of the Pad of any
Habitable Area no lower than 2.5 m above the Natural Ground Elevation, provided that:
(1)
the difference between the FCL and the ground exceeds 2.5 m;
(2)
the owner has provided a report from a Qualified Professional that the land can be
used safely for the intended purpose; and,
(3)
the owner enters into a Covenant, absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures and
contents thereof.
10.
Structural support or compacted landfill or a combination of both may be used to elevate
the underside of the floor system or the top of the Pad to the requirements specified in
Section 8 and 9 of this Bylaw.
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 6
Consolidated: July 17, 2018
Flood Protection Requirements in Yarrow and Greendale
11.
Within the Yarrow Area and Greendale Areas shown on Schedule "A", attached hereto
and forming part of this Bylaw, a building may be constructed, reconstructed, moved or
extended, or a Manufactured Home located with the underside of the lowest Habitable
Area, at a minimum elevation of 1.2 m above the Natural Ground Elevation, or no less
than 0.3 m above the crown of the adjacent road, whichever elevation is greater; provided
that:
(1)
the owner has provided a report from a Qualified Professional that the land can be
used safely for the intended purpose; and,
(2)
the owner enters into a Covenant absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures and
contents thereof.
12.
Structural support or compacted landfill or a combination of both may be used to elevate
the underside of the floor system or the top of the Pad to the requirements specified in
Section 11 of this Bylaw.
Flood Protection Requirements North and East of Shefford Slough, South of Cartmell Road and
West of Young Road
13.
Within the area north and east of Shefford Slough, south of Cartmell Road and west of
Young Road as shown on Schedule "A", attached hereto and forming part of this Bylaw,
a single family dwelling may be constructed provided that:
(1)
the underside of the lowest Habitable Area is above the applicable FCL;
(2)
any entrance foyer or crawlspace shall be no lower than the applicable FCL minus
1.5 m;
(3)
furnaces, hot water heaters and electrical panels shall be located above the FCL;
(4)
any electric circuits extending below the FCL shall be equipped with ground fault
circuit breakers; and,
(5)
the owner enters into a Covenant absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures
and contents thereof.
14.
Structural support or compacted landfill or a combination of both may be used to elevate
the underside of the floor system or the top of the Pad to the requirements specified in
Section 13 of this Bylaw. The structural support and landfill shall be adequately protected
against erosion by floodwaters.
Flood Protection Requirements for Areas Not Protected by a Standard Dike
15.
No building or structure is permitted to be constructed in the Floodplain in an area not
protected by a Standard Dike as depicted on Schedule "A", attached hereto and forming
part of this Bylaw, except a renovation or addition to a building as specified in Section
21 of this Bylaw. (AB#4557)
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 7
Consolidated: July 17, 2018
Flood Protection Requirements on an Alluvial Fan
16.
Construction on an Alluvial Fan as designated on Schedule "A", attached hereto and
forming part of this Bylaw, shall be in accordance with Provincial Guidelines and meet
the following requirements:
(1)
a site specific assessment by a Qualified Professional is required to determine
building setback and elevation requirements;
(2)
an engineered concrete foundation shall extend to a minimum of 1.0 m above the
grade at any point on the perimeter of the building on an Alluvial Fan;
(3)
the design, construction, operation and maintenance of the protective works shall
be certified by a Qualified Professional to ensure that structures are anchored to
minimize the impact of flood, sediment and erosion damage;
(4)
footings shall be extended below scour depth, erosion and flood flows;
(5)
where protective works are required, an ongoing maintenance program shall be
required as part of the covenant agreement between the City of Chilliwack and an
owner, or a strata corporation;
(6)
where works protect more than one property:
(a)
easements or rights of way for the works and access to the works must be
registered in favor of the City of Chilliwack;
(b)
an Operation and Maintenance manual must be prepared for the City of
Chilliwack with a copy to the Inspector of Dikes;
(c)
Training Works or a dike protecting more than one property must be
approved by the Inspector of Dikes; and may also require approval under
the Provincial Water Sustainability Act and the Federal Fisheries Act.
Flood Protection Requirements in Debris Flow Hazard Areas
17.
A site specific assessment by a Qualified Professional is required to determine building
setback and elevation requirements, and construction of protective works, in Debris Flow
hazard areas, which are broadly included in Development Permit Area No. 2 - Hillside
and Upland Areas.
GENERAL EXEMPTIONS
Agricultural Exemptions
18.
The elevation requirements above shall not apply to:
(1)
farm buildings and open-sided livestock housing (other than dwelling units and
closed-sided livestock housing) protected by a Standard Dike;
(2)
farm buildings and open-sided livestock housing (other than dwelling units and
closed-sided livestock housing) not protected by a Standard Dike, on the condition
that the owner provides a Qualified Professional's report indicating that the
property may be safely used for the intended purpose;
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 8
Consolidated: July 17, 2018
GENERAL EXEMPTIONS (continued)
Agricultural Exemptions (continued)
(3)
closed-sided livestock housing protected by a Standard Dike if elevated to 0.6 m
above the Ponding Elevation;
(4)
closed-sided livestock housing, not protected by a Standard Dike, if elevated to
1.0 m above Natural Ground Elevation or 0.6 m above the Ponding Elevation or
the FCL minus 1.5 m, whichever is greater on the condition that the owner
provides a Qualified Professional's report indicating that the property may be
safely used for the intended purpose.
19.
Where a lot is within the Agricultural Land Reserve, a dwelling unit thereon may be
constructed with the underside of a wooden floor system or the top of the Pad of any
Habitable Area no lower than 1.2 m above the Natural Ground Elevation or 0.3 m above
the crown of the adjacent road, whichever elevation is greater, provided that:
(1)
the property is protected by a Standard Dike; and,
(2)
the owner enters into a Covenant, absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures and
contents thereof.
Other Land Use Exemptions
20.
The elevation requirements in this Bylaw shall not apply to:
(1)
industrial uses within areas designated for industrial use in the City of Chilliwack
"Official Community Plan", as amended from time to time, or occupied by an
industrial use and which are protected by a Standard Dike, provided that:
(a)
the underside of the lowest floor system or surface of the floor slab is no
lower than 0.15 m above the crown of the nearest road where water may
pond; and, (AB#4557)
(b)
fixed equipment susceptible to damage by floodwaters is no lower than the
FCL.
(2)
on-loading and off-loading facilities associated with water oriented industry and
portable sawmills provided the main electrical switchgear is placed above the
FCL;
(3)
commercial uses within the Downtown Land Use Plan Area as indicated in the
Chilliwack "Official Community Plan", as amended from time to time, and which
are protected by a Standard Dike, provided the underside of the lowest floor
system or surface of the floor slab is no lower than 0.15 m above the crown of the
nearest road where water may pond;
(4)
commercial uses not within the Downtown Land Use Plan Area as indicated in the
"Chilliwack Official Community", as amended from time to time, other than
tourist accommodation units, and which are protected by a Standard Dike,
provided the underside of the lowest floor system or surface of the floor slab is no
lower than 0.30 m above the crown of the nearest road where water may pond;
(5)
an ancillary building such as a garage or workshop;
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 9
Consolidated: July 17, 2018
GENERAL EXEMPTIONS (continued)
Other Land Use Exemptions (continued)
(6)
that portion of a building or structure to be used as a carport, garage, entrance
foyer and mechanical room including hot water tanks and furnaces in buildings
protected by a Standard Dike; and,
(7)
recreation shelters and washrooms.
BUILDING SIZE EXEMPTIONS
21.
The elevation requirements in this Bylaw do not apply to:
(1)
a renovation or addition to a building or structure that would increase the size of
the building or structure, at the original Non-Conforming floor elevation, by less
than 25 percent of the floor area existing at the date of the adoption of
"Floodplain Management Bylaw 1996, No. 2395" (March 3, 1997); and,
(2)
that portion of a building consisting of crawl space.
RESIDENTIAL AND INSTITUTIONAL USES PERMITTED BELOW A FCL
22.
The area below the FCL as applied to a residential or Institutional Use may be used for
entrance foyer, utility room, workshop or indoor Recreation Uses provided that:
(1)
the floor level of all of these areas is at least 0.30 m above the crown of the
nearest road where water may pond; and, (AB#4557)
(2)
the owner enters into a Covenant absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures and
contents thereof.
SITE SPECIFIC APPLICATION
23.
Notwithstanding the above, Council may grant a site specific exemption with respect to
the setback requirements or elevation requirements elsewhere in this Bylaw where:
(1)
a Qualified Professional has submitted an application in accordance with the City
of Chilliwack "Guidelines for Site Specific Application", attached hereto as
Schedule "B", and forming part of this Bylaw;
(2)
a Qualified Professional has submitted a site specific report, consistent with
Provincial Guidelines and EGBC Professional Practice Guidelines, and
supplemented with a flood hazard and risk assurance statement as specified in
Appendix J of EGBC Professional Practice Guidelines, that certifies that the
property can be safely used for the intended use and that protection from a 1 in
200 year flood on the Chilliwack River, Vedder River and Vedder Canal or from
the 1894 flood on the Fraser River can be achieved through an engineered design
without reliance on a Standard Dike; and,
(3)
the owner enters into a Covenant absolving the City of Chilliwack of any liability
with respect to the flooding of the property or flood damage to land, structures and
contents thereof.
"Floodplain Regulation Bylaw 2018, No. 4519" - Page 10
Consolidated: July 17, 2018
INSPECTION
24.
No person shall interfere with or obstruct the entry of any authorized representative of the
City of Chilliwack, on the land or into any structure, with respect to the administration or
enforcement of this Bylaw.
OFFENCE
25.
No person shall contravene, cause, or permit a contravention of this Bylaw.
PENALTY
26.
Any person contravening any provision of this Bylaw is liable on summary conviction to
a fine under the Offence Act of not more than $2,000. Each day that the offence occurs
constitutes a separate offence.
SEVERABILITY
27.
If any part of this Bylaw is for any reason held to be invalid by the decision of any Court
of competent jurisdiction, the part of the Bylaw held to be invalid shall be struck from the
Bylaw and the decision shall not affect the validity of the remainder of the Bylaw.
Received first and second reading on the 17th day of April, 2018.
Received third reading on the 17th day of April, 2018.
Received adoption on the 1st day of May, 2018.
Amendment Bylaw No. 4557 adopted on the 17th day of July, 2018.
"Chris Kloot"
A/Mayor
"Jacqueline Morgan"
Corporate Officer
"Floodplain Regulation Bylaw 2018, No. 4519" - Schedule "A"
Consolidated: July 17, 2018
SCHEDULE "A"
"Floodplain Regulation Bylaw 2018, No. 4519" - Schedule "B" - Page 1
Consolidated: July 17, 2018
SCHEDULE "B"
DEFINITIONS1
GUIDELINES FOR SITE SPECIFIC APPLICATION BY A QUALIFIED PROFESSIONAL
1.
Quality Assurance Statement
I hereby certify:
I am a Professional Engineer or Professional Geoscientist, with experience in
geotechnical engineering, geohazard assessment and river hydrology;
I am licensed in the Province of British Columbia; and,
I am qualified to carry out the following flood hazard assessment and that I have
performed an evaluation of the area of the proposed development in accordance with the
'Flood Hazard Area Land Use Management Guidelines' of the Province of British
Columbia and the 'Professional Practice Guidelines - Legislated Flood Assessments in a
Changing Climate in BC' adopted by EGBC.
Name:
Signature
2.
General Requirements
(1)
Legal Description of the property.
(2)
General Location map of the property.
(3)
Detailed map of the property showing property boundaries, safe areas for
development, watercourses, topography and physical features.
(4)
Statement of conformance to "Floodplain Regulation Bylaw 2018, No. 4519", in
force from time to time, and Provincial Guidelines.
(5)
Review of all relevant Covenants registered on title (copies of Covenants, if
relevant, should be attached to the report.)
(6)
Review of all relevant previous reports and flood hazard maps affecting the site
and surrounding area.
(7)
Review of current and historical air photos.
(8)
Description of site visits and observations.
(9)
Review of historical flood information including stream flow data, climate data
and local observations.
1 Definitions from 2012 APEGBC Guidelines, 2004 Provincial Guidelines and City of Chilliwack "Floodplain
Regulation Bylaw 2018, No. 4519".
"Floodplain Regulation Bylaw 2018, No. 4519" - Schedule "B" - Page 2
Consolidated: July 17, 2018
2.
General Requirements (continued)
(10)
Assessment of the nature, extent, magnitude, frequency and potential effect of all
flood or Debris Flow hazards that may affect the property.
(11)
Description of the scientific methodology(s) and assumptions used to undertake
the assessment in sufficient detail to facilitate a professional review.
(12)
The location of all proposed building sites and specified setback distances from
the Natural Boundary of watercourses. (Maps must be delineated with sufficient
accuracy and detail to allow the preparation of a legal reference plan for
attachment to a Covenant).
(13)
Recommendations to ensure safe use of a site. (These should be clearly stated
with sufficient detail and clarity to facilitate inclusion in a Covenant).
(14)
Description of proposed mitigation works and/or actions designed to mitigate the
hazard with confirmation that the Provincial Guidelines have been considered.
(15)
Where mitigation works and/or actions area proposed, an assessment of the effects
that the proposed works and/or actions may have on other properties including
public infrastructure.
(16)
Where mitigative works and/or actions designed to reduce hazards are
contemplated, prior to completion the report and expending time and money on
the detailed design, the proponent should confirm that the works and/or actions
proposed will be accepted by the City of Chilliwack and that they would meet
Provincial regulatory requirements and will be approved by the Inspector of
Dikes.
SPECIAL CASES
3.
Watercourses
(1)
Where Floodplain maps are used to recommend FCLs, document which map was
used.
(2)
Where an existing FCL shown on a Floodplain map is deemed inappropriate, or
where a new FCL is recommended, provide details of the calculation and
confirmation that the Guidelines were considered in the process.
(3)
For property adjacent to or within a meandering and/or braided river Floodplain,
use air photos, maps and other information to describe and assess relevant
ongoing river processes that may pose a hazard to the property.
(4)
When recommending the use of minimum setback and elevation guidelines for
smaller streams, provide a map of the stream watershed area to determine
drainage area.
"Floodplain Regulation Bylaw 2018, No. 4519" - Schedule "B" - Page 3
Consolidated: July 17, 2018
5.
Alluvial Fans
(1)
Provide a suitably scaled topographic map depicting watershed area, fan
boundaries, existing and abandoned channels, hydraulic structures, existing and
proposed mitigation works, potential avulsion and overland flow paths for the 1 in
200 year flood event, features on the fan that would serve to give direction to
and/or impede overland and/or channel avulsion flow paths and the property
boundaries.
(2)
Provide channel cross-sections, stream profiles, and depths of flow and flow
velocities used in the analysis.
(3)
Provide an assessment of the sensitivity of the watershed area, with respect to
hydrology and sediment and debris loading.
(4)
Provide an assessment of the long-term channel bed load and debris maintenance
requirements in relation to any recommended flood hazard mitigation measures.
(5)
Where existing channel capacity and topographic features on the fan are identified
as features contributing to the safe use of the property, provide an assessment of
the effects of any future changes to the channel or fan topography.
(6)
Provide plan, cross-sections and design specification for proposed building
foundation treatments and to the site specific measures.
6.
Area Subject to Debris Flows
(1)
Provide a suitably scaled topographic map and/or air photographic base map
depicting watershed area, all existing and potential Debris Flow start, transport
and run out zones, hydraulic structures, existing and proposed mitigation works,
features on the Debris Flow transport path and/or run out area which could serve
to give direction and/or impede Debris Flows, existing depositional features,
cohorts, soil test pit locations, carbon dating and dendrochronology sample sites,
and property boundaries.
(2)
Provide a statement of return periods considered in the hazard assessment and
design of proposed mitigation works.
(3)
Provide a centerline profile from Debris Flow start zones to toe of run out zones.
(4)
Provide plans, cross-sections and design specifications for proposed mitigation
works, event volume, depth and velocity of flow and impact forces used in the
design of mitigation works.
(5)
Provide an assessment of the sensitivity of watershed area with respect to
hydrology and sediment and debris loading.
(6)
Where existing channel capacity and topographic features on the fan are identified
as features contributing to the safe use of the property, provide an assessment of
the effects of any future changes to the channel or fan topography.