+ All Categories
Home > Documents > Minden flood planning opinion Heather Sadler

Minden flood planning opinion Heather Sadler

Date post: 03-Jan-2016
Category:
Upload: jennwattecho
View: 470 times
Download: 0 times
Share this document with a friend
Description:
Planning opinion prepared by EcoVue consultant Heather Sadler for the Township of Minden Hills regarding floodplains.
Popular Tags:
17
Dear Reeve Reid and Members of Council: For the Village of Minden, the spring of 2013 will long be remembered as the spring when the Gull River rose up over its banks and flooded the downtown. The devastation that the flood waters bring is very real, both in the short term and the longer term. It is one of the few examples of the power of the natural environment that still manages to render us almost powerless. Short of piling sandbags, there is little we can do except join together to support each other in our time of collective need. Having said that, there are lessons to learn about how to avoid this level of devastation and despair in the future. This paper has been prepared, as a donation to the municipality, to provide assistance to the Township of Minden Hills and its residents regarding the flooding that has occurred and more importantly, what can be done in the future. We have included some history of the known risk of flooding along the Gull River and also provided some guidance with respect to planning initiatives which can help the community to prepare for future flooding events. It is hoped that the municipality may find this information helpful as it tackles the challenges of managing flood prone lands in the village and along the Gull River to the south. The paper is based on our professional experience and understanding of flooding hazards in general and our familiarity with the village of Minden in particular. As a former Manager of Planning and Regulations with the Otonabee Region Conservation Authority in Peterborough, and a June 17, 2013 Reeve Reid and Members of Council Township of Minden Hills P.O. Box 359, Minden, Ontario K0M 2K0. Attn: Nancy Wright-Laking CAO, Clerk and EDO Re: Planning Opinion 2013 Minden Flood In Support of Flood Damage Relief Efforts
Transcript
Page 1: Minden flood planning opinion Heather Sadler

Dear Reeve Reid and Members of Council:

For the Village of Minden, the spring of 2013 will long be remembered as the spring when the Gull

River rose up over its banks and flooded the downtown. The devastation that the flood waters

bring is very real, both in the short term and the longer term. It is one of the few examples of the

power of the natural environment that still manages to render us almost powerless. Short of piling

sandbags, there is little we can do except join together to support each other in our time of

collective need.

Having said that, there are lessons to learn about how to avoid this level of devastation and

despair in the future. This paper has been prepared, as a donation to the municipality, to provide

assistance to the Township of Minden Hills and its residents regarding the flooding that has

occurred and more importantly, what can be done in the future. We have included some history of

the known risk of flooding along the Gull River and also provided some guidance with respect to

planning initiatives which can help the community to prepare for future flooding events. It is hoped

that the municipality may find this information helpful as it tackles the challenges of managing flood

prone lands in the village and along the Gull River to the south.

The paper is based on our professional experience and understanding of flooding hazards in

general and our familiarity with the village of Minden in particular. As a former Manager of Planning

and Regulations with the Otonabee Region Conservation Authority in Peterborough, and a

June 17, 2013

Reeve Reid and Members of Council Township of Minden Hills P.O. Box 359, Minden, Ontario K0M 2K0.

Attn:

Nancy Wright-Laking CAO, Clerk and EDO

Re: Planning Opinion

2013 Minden Flood In Support of Flood Damage Relief Efforts

Page 2: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 2

Registered Professional Planner in the Province of Ontario, the undersigned has extensive

experience in flood plain management and policy. We felt it was important that this perspective be

shared with the Township of Minden Hills. This paper is our contribution to the Disaster Relief

initiative. There is no fee for this information and we expect nothing in return. We simply hope that

the information will assist the municipality with this ongoing issue.

1. BACKGROUND

Land use planning policy in the Province of Ontario is quite clear about the manner in which new

development must be planned to avoid damage from flooding. Protection against damage to

property and damage to life and limb are key aspects of the Natural Hazards policies set out in the

Provincial Policy Statement.

In many ways, these policies grew out of the experiences of Hurricane Hazel. In 1954, Hazel

struck Canada as an extra-tropical storm, with a death toll in the Toronto area of 81 people.

Approximately 4,000 homes were destroyed and more than a billion dollars (2009 dollars) in costs

including economic disruption, the cost of property losses and recovery costs resulted. The effects

of Hazel in Toronto were unprecedented, as a result of a combination of a lack of experience in

dealing with tropical storms and the storm's ferocity. Other floods, such as the 1974 Grand River

flood (Cambridge–Galt), the 1961 Timmins storm, and the 1980 Ganaraska River (Port Hope), also

underscored the vulnerability of communities to extreme flood events. More recently the

Peterborough floods of 2002 and 2004 have reminded residents in this area that flooding can

occur at any time and that communities built in the floodplains of rivers are always vulnerable.

1.1 History of Flooding In Minden

Based on historical photos and recollections of long-time residents of Minden, it is clear that the

flooding experienced this past spring is typical of serious flood events affecting the Gull River and

the village of Minden. According to historic records, the Gull River has overflowed its banks in the

village of Minden on a number of occasions. Flooding is documented as far back as 1913, 1928,

and 1929, as well as 1943, 1950, and 1983. It was as a result of the 1983 flooding, that measures

were initiated to better understand the flooding risk along the Gull River and to manage this risk

more effectively.

Page 3: Minden flood planning opinion Heather Sadler

Source: Spring 1943 - Between Anson Street and Bobcaygeon Road, southwest from Peck Street - courtesy of the FRDP Public Information Flood Risk Map for the Gull River, 1988

Page 4: Minden flood planning opinion Heather Sadler

Spring 1951 - Flooding on Peck Street in Minden, looking northwest towards the Gull River- courtesy of the FRDP Public Information Flood Risk Map for the Gull River, 1988

Page 5: Minden flood planning opinion Heather Sadler

Source: - May 1983 - flooding ON Anson Street in Minden,looking north courtesy of the FRDP Public Information FloodRisk Map for the Gull River, 1988

Page 6: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 4

2. THE CANADA-ONTARIO FLOOD DAMAGE REDUCTION PROGRAM

In some cases flooding can be managed by attempting to modify natural systems, through dams,

dykes and channelization works. This approach is very costly and does not guarantee that a flood

event can be controlled. In 1975, the federal government initiated Flood Damage Reduction

Program (FDRP), through Environment Canada, to curtail escalating disaster assistance payments

in known flood risk areas, as well as the reliance on costly structural measures.

The FDRP consists of three steps. The first is to identify and map flood risk areas. The second is

to designate these areas as being at risk of flooding by publishing Public Information Flood Risk

Maps which show the extent of flooding. The third step is to apply policies to discourage future

development in flood prone areas which have been identified through the program. Once a flood

risk area is mapped and designated both the federal and provincial governments agree not to build

or support (e.g., with a financial incentive) any future flood vulnerable development in those areas.

New development is not eligible for disaster assistance in the event of a flood.1

Local governments also play an important role in flood plain management, since they are generally

responsible for land use planning and regulation of new development. The FDR agreements

require that local authorities be encouraged to zone according to flood risk in designated areas. In

some provinces, the local levels of government are required to incorporate flood hazard

information into municipal planning through official plans, zoning bylaws, subdivision plans, and

flood and fill regulations.

2.1 The Minden FDRP

In the case of Minden, flood plain mapping was completed for the Gull River in 1988. This mapping

was prepared under the Canada-Ontario Flood Damage Reduction Program. The flood risk areas

were determined through hydrologic and hydraulic analyses conducted in 1986 by Paragon

Engineering Limited.2 The analysis of the extent of the flood risk area associated with the Gull

River was calculated on the basis of the most severe thunderstorm on record for the area. The

FDRP mapping for the Gull River extends from the dam at the bottom end of Minden Lake to the

1 http://www.ec.gc.ca/eau-water ‘Environment Canada - Flood Damage Reduction Program’ 2 Public Information Flood Risk Information Map – Gull River – Township of Anson, Hindon & Minden and the Township of Lutterworth. Canada-Ontario Flood Damage Reduction Program, 1988.

Page 7: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 5

outflow of the river into Gull Lake at Sandy Bay (see Figure 1 below).. Detailed mapping of the

floodplain was provided to the municipality through the FDRP program. Copies are also available

through MNR.

Source: FDRP Public Information Flood Risk Map - Gull River

2.1.1 Calculating the extent of the flooding hazard

Paragon Engineering would have used sophisticated computer models to determine the extent of

flooding that would occur on the Gull River, based on established records of the area’s most

severe flood event. In many areas, the 1:100 year storm event is used as the basis for modelling

the anticipated extent of flooding from a major storm event. For the Gull River, the historic event

used to calculate flooding is the Timmins Storm, which occurred in August of 1961. The flooding

resulting from the Timmins Storm exceeded that of the one hundred year flood, often referred to as

Page 8: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 6

the 1:100 year flood event. The 1:100 year flood is based on an analysis of precipitation, snow

melt, or a combination of the two. The chance of it occurring is once in one hundred years or

conversely a 1% chance of happening in any given year. Contrary to popular opinion (‘gamblers

fallacy’), this does not mean that such an event will only happen once every one hundred years. In

the City of Peterborough’s case, two ‘one hundred year floods’ occurred within two years (2002

and 2004). As such, municipalities and landowners must understand that areas within a floodplain

are always susceptible flooding and that this flooding can occur at any time.

3. PROVINCIAL POLICIES AFFECTING FLOODPLAINS

Section 3.1 of the Provincial Policy Statement requires, in part, that development should be

directed to areas outside of hazardous lands along rivers, streams and small inland lake systems.

No development is permitted within the floodway, regardless of whether there are highpoints within

the floodway which are not susceptible to flooding. Section 3.1.2 further requires that development

and site alteration shall not be permitted in areas that would be rendered inaccessible during times

of flooding (3.1.2 c)); and in a floodway (3.1.2 d)).

3.1.1 The Two Zone Concept

Floodplains are the areas adjacent to rivers which have been or may in future be subject to

flooding hazards.3 Generally, development and site alteration is not permitted within the floodplain

of river, stream and small inland lake systems, in accordance with the policies of the PPS.

In some cases, the flood plain of the river has been divided into two zones, based on the mapping

produced through the FDRP project. This is called a two-zone concept for flood management

purposes. The floodway is the inner portion of the floodplain where flood depths and /or velocities

pose a threat to life and/or property damage. The outer portion of the flood plain is called the

flood fringe. Flood depths and velocities are generally less severe than those experienced in the

floodway. Provincial policy allows development and site alteration within the flood fringe in

communities where a two-zone concept has been applied. The PPS states unless a two-zone

concept has been applied, the entire floodplain is considered to be the floodway. No development

or site alteration is permitted within a floodway.

3 Provincial Policy Statement – Definitions pg. 30.

Page 9: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 7

A two-zone concept has been applied to the Gull River system, based on the FDRP mapping

project completed in 1988. This means that development and site alteration may occur in the flood

fringe, provided certain measures are taken to reduce the risk of damage (e.g. floodproofing).

3.1.1.1 LOCAL MUNICIPAL ROLE IN FLOOD PLAIN MANAGEMENT

Documentation included with the 1988 FDRP Public Information Flood Risk Map states that the

Councils of the Township of Anson, Hindon and Minden and the Township of Lutterworth

supported the objectives of the FDRP program, including discouraging development in areas

vulnerable to flooding.

3.2 Minden Hills Official Plan and Zoning By-law

The current Official Plan for Minden Hills includes policies for ensuring that the floodplain is

managed properly. Schedule “C” to the Official Plan identifies the Floodway of the Gull River. The

Official Plan does not identify the flood fringe areas. For lands within the Floodway designation, the

erection of buildings or structures, or the removal or placing of fill of any kind, is prohibited except

where such buildings or structures are intended for flood or erosion control or bank stabilization.

Floodway – area where development and site alteration should not occur (dark pink) Flood fringe – area where development and site alteration may occur, subject to certain restrictions (light pink)

Page 10: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 8

The current Official Plan also contains policies that address Non-Conforming Uses. The Plan

specifically states that “any land use legally existing prior to the approval of this plan which does

not conform to the permitted uses of this plan, should cease to exist in the long term. In

extenuating circumstances, it may be desirable to permit the extension or enlargement of the non-

conforming use, in order to prevent undue hardship”4.

The Plan also allows that certain uses of land that existed at the date of approval of the Plan may

be deemed to conform to the intent of this plan for the purpose of a zoning bylaw. However, this

flexibility does not extend to properties which are located within the flood way portion of a river or

stream system’s flood plain.5 The intent of this policy is to ensure that buildings located in the

floodway which are damaged or destroyed are not rebuilt.

4 Section 10.1.4.2 of the Minden Hills Official Plan, p.47. 5 Ibid., p. 48.

Page 11: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 9

3.2.1 Flood Risk Zone Overlay

The Township’s Zoning By-law 06-10 is intended to implement the policies of the Official Plan. The

By-law includes provisions for a Flood Risk (FR) Zone Overlay on Schedule 25 for the Gull River,

south of the Village of Minden (Section 5.3.3.1

During our tenure as Planning Consultants for the Township of Minden Hills, we noted that there

are a number of technical errors associated with the delineation of the floodplain on the Zoning

Schedules for the Gull River. The FR overlay on Schedule 25, includes partial line segments,

which do not reflect the topographic contours used to generate the maps. Parts of the flood fringe

do not appear on the map at all (north side of the Gull River south of Orde Street). These errors

make implementation of the Zoning By-law difficult.

There is no flood fringe identified in this part of the flood plain Some line segments do not make sense in terms of flood elevations

Page 12: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 10

3.2.2 Floodway Zone

The By-law also includes a Floodway (FW) Zone for the Village of Minden (Schedules 21 and 22)

and the Gull River (Schedule 25). The FW Zone permits only existing buildings and structures, as

well as open space, conservation, agriculture, recreation and forestry uses. However, despite the

fact that the Official Plan states that existing buildings located in the floodway are considered to be

non-conforming (and therefore not eligible for reconstruction), the Zoning By-law permits “the

extension, enlargement or repair of existing buildings or structures with the requirement of flood

proofing measures as noted in Section 5.3.5, and provided that such extension or enlargement is

not greater in size than 50% of the existing structure as determined by the ground floor areas”.6

This approach is contrary to the Official Plan and contrary to Provincial policy.

In areas where a two-zone concept is applied, the PPS permits development in the flood fringe,

subject to appropriate flood proofing. Development and site alteration in the floodway in not

permitted, regardless of whether floodproofing measures are proposed.

3.2.3 Flood Proofing Zone

The By-law also includes a Flood Proofing (FP) Zone within the Minden Urban Area. The By-law

describes the FP Zone as an overlay zone, which places restrictions on building openings for

permitted uses. The intent is that building openings should be not be below the levels noted in the

FDRP program schedules. Regrettably, Schedules 21 and 22 do not include an overlay for the FP

Zone. As a result, the Zoning By-law recognises only the extent of the floodway, but not the area

subject to flooding within the flood fringe for areas within the village of Minden. The failure to

identify the full extent of the extent of the flood fringe leads landowners and others to believe that

the extent of flooding is much less than is actually the case. The figure below is an excerpt from

Schedule 22 to the Zoning By-law, which illustrates the fact that the FP Zone was not applied to

the flood fringe within the village - only the floodway is identified. On this basis, the Township’s

Zoning By-law is not consistent with the PPS.

6 Township of Minden Hills Zoning By-law 06-10, Section 5.3.4.1, p. 48

Page 13: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 11

4. OPPORTUNITIES FOR IMPROVEMENTS

EcoVue is concerned that the planning documents (Official Plan and Zoning By-law) which the

municipality relies on as tools for flood plain management do not reflect the extent of flood risk

which affects the community. The most recent flood event provided tangible evidence for the

importance of accurate mapping and sound policies for management of land uses within the flood

prone areas of the village of Minden. The following is a short list of concerns which we recommend

be addressed by the municipality, so that future events are less likely to cause the extent of

damage and devastation experienced in the spring of 2013.

4.1 Update to Official Plan

The Floodway Management policies, included in the previous draft, have been removed in the

most recent draft of the update to the Official Plan. Instead the draft includes policies referring to a

Hazards Lands Overlay. These draft policies apply to all areas which are subject to possible

Monk Funeral Home LCBO Residential area - Prince Street Invergordon Fire Hall

Page 14: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 12

hazards, of various types. The mapping does not reflect the results of the FDRP mapping and the

two-zone concept developed for the Gull River. As stated earlier, if a two-zone concept is not

applied, then a one-zone concept is applicable. No development is permitted within the floodplain

(both floodway and flood fringe) of a river, stream or small inland lake. The draft policies are not

consistent with one-zone floodplain management.

The two zone concept provides some level of flexibility for site alteration and development within

the identified flood fringe of the Gull River. It would be to the municipality’s advantage to maintain

the two-zone concept developed through the FDRP project in the new Official Plan and to make

provisions for proper implementation through the Zoning By-law.

We note that Section 2.7.5.4 of the draft Plan refers to development within a floodway, but there is

no reference made to the 1988 delineation of the floodway of the Gull River. The definition of

floodway included in Section 2.7.5.3 is not consistent with the PPS definition of a floodway, as

required by provincial legislation.

In our opinion, the policies, as drafted, lessen development restrictions within the floodplain of the

Gull River, thereby putting people and property at potential risk from future flood events. The

policies are contrary to Section 3.1 of the PPS, insofar as the policies ignore the delineated

floodway, identified in the 1988 FDRP study. The policies also fail to reflect the commitment made

by the previous Councils for the Township’s of Anson, Hindon and Minden and Lutterworth, in

terms of supporting the objectives of the Canada-Ontario Flood Damage Reduction Program.

Schedule A1 to the Official Plan does not identify the flood way and flood fringe of the Gull River,

established through the FDRP mapping. The Hazard Lands Overlay does appear to coincide with

areas identified by the FDRP mapping7.

Finally, the policies make no mention of implementing the two-zone concept for the Gull River in

the Zoning By-law. This should be specifically addressed in the new Official Plan.

7 It may be that the new mapping is believed to more accurately reflect the extent of flooding than the FDRP mapping. Unfortunately it does not reflect the detailed FDRP floodway/floodfringe data.

Page 15: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 13

4.2 Zoning By-law

We are aware that the Township has been considering an update to their Zoning By-law for some

time now. In fact, EcoVue had previously recommended that an Update to the By-law should be

completed, to address concerns with floodplain delineation in the existing By-law. We continue to

recommend that an update to the floodplain mapping and policies be updated at the earliest

opportunity. Particular attention should be paid to the delineation of the FW, FR and FP Zones in

the update, as this mapping is an important tool for ensuring that owners and prospective

purchasers are aware of the flood risk associated with their properties. Of course, the mapping

delineation does not reduce the risk of flooding, but it can reduce the impact of flooding on

property and persons.

The mapping should clearly show that the area included in the flood fringe of the Gull River is

subject to flooding, including Prince Street, Chandos Street, St. Germaine, Water Street,

Bobcaygeon Road, Invergordon Avenue, Anson Street, Peck Street, McKnight Drive, and Orde

Street. Flood proofing elevations should be included for all areas within the delineated flood fringe

of the Gull River, to assist the Municipality’s Planning and Building Division in ensuring that proper

floodproofing measures are undertaken in for properties within the flood fringe.

4.3 Location of Emergency Services

Section 3.1.4 of the Provincial Policy Statement states that essential emergency services, such as

that provided by fire, police and ambulances and electrical substations which would be impaired

during an emergency as a result of flooding, the failure of floodproofing measures and/or

protection works, and or erosion shall not be permitted to locate in hazardous lands. Lands which

are located within the floodplain of a river, stream or small inland lake system are categorized as

hazardous lands.

The municipality currently has been considering an opportunity to relocate its fire and emergency

services to an area beyond the floodplain of the Gull River. The recent flooding demonstrates the

vulnerability of the current location in the delivery of emergency services to the community.

Page 16: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 14

4.4 Funds for Relocation of Flood Prone Residences

Three residences must be demolished and rebuilt, as a result of the flood. Council could consider

directing some of its funds towards assisting residents of these homes to relocate to areas outside

the floodway, rather than in attempts to rebuild the homes on flood prone lands where damage

from future flooding is inevitable.

For residents within the flood fringe, it will be important that any reconstruction and repair

undertaken is consistent with the floodproofing provisions of the Zoning By-law. No additional fill

should be placed in the floodplain, as this leads to displacement of floodwaters and increased

flooding elsewhere.

4.5 Updated Flood Mapping

The current FDRP mapping does not fully reflect the extent of the flooding which occurred in the

spring of 2013. We do not know whether this is because the storm characteristics were more

extreme and water levels existing at the time were greater than had been previously assumed, or

whether additional development in the floodplain caused displacement if floodwaters into areas not

previously prone to flooding. Regardless, the Municipality should contact the Province and

Environment Canada to request an update mapping to reflect the 2013 conditions. This is one

matter for which the municipality should be able to leverage political support, based on the effects

of the 2013 flood event.

5. FINAL COMMENT

As a final comment, it should be noted that flooding is an unpredictable, natural event, much like

tornados, grass fires and earthquakes. Problems arise when development is permitted to continue

in areas which are vulnerable to flooding. Instead, residents and others should be encouraged to

come to terms with a river's natural regime and to adjust their expectation accordingly.

There is a general agreement that climate change is resulting in more storms and in increased

severity of storms. Properties within the regulatory floodplain of the Gull River must expect that

flooding will continue to occur, perhaps more often than it has in the past. What is most important

is that the community works together to ensure that risk to persons and property is reduced in the

Page 17: Minden flood planning opinion Heather Sadler

Flood Plain Management on the Gull River Township of Minden Hills

June 12, 2013

P a g e | 15

wake of the 2013 flood event. Implementation of appropriate land use policies and regulations are

a valuable tool in this regard.

It is understandable that Councillors, municipal staff, and local residents of Minden had little or no

understanding of the extent of potential flooding in Minden prior to the 2013 flood. The municipality

has very limited experience to drawn upon in developing proactive planning policies and

regulations for the community, in developing a response to this serious flood event. Regrettably,

plans being put in place now do not appear to reflect the flood plain management policies

developed for Minden more than twenty-five years ago.

It appears that few people are aware of the detailed policies and programs which are in place to

deal with the potential for damages from future flood events. It is EcoVue’s hope that the

information included herein will assist the municipality in its understanding of the complexity of

flood plain management and the resources available to it, through the FDRP program to limit

damage from future flood events.

Respectfully submitted, , ECOVUE CONSULTING SERVICES INC.

Heather Sadler B.A. M.A. MCIP RPP Principal and Senior Planner


Recommended