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4.1
District of Maple Ridge
COUNCIL WORKSHOP AGENDA
June 20, 2011
9:00 a.m.
Blaney Room, 1st Floor, Municipal Hall
The purpose of the Council Workshop is to review and discuss policies and
other items of interest to Council. Although resolutions may be passed at
this meeting, the intent is to make a consensus decision to send an item to
Council for debate and vote or refer the item back to staff for more
information or clarification.
REMINDERS
June 20, 2011
Closed Council following Workshop
Committee of the Whole Meeting 1:00 P.M.
June 21, 2011
Public Hearing 7:00 p.m.
ADOPTION OF THE AGENDA
MINUTES -June 13, 2011
PRESENTATIONS AT THE REQUEST OF COUNCIL
UNFINISHED AND NEW BUSINESS
Recycling Update, Maple Ridge Recycling Society
- Kim Day, Executive Director
4.2 Alouette Rivers Hydrotechnical Model
Staff report dated June 20, 2011 providing information on the development of a
hydrotechnical model of the Alouette River flood plain and the Executive Summary
of the findings (attached).
Council Workshop
June 20, 2011
Page 2 of 3
4.3 Blue Mountain Update
Staff report dated June 20, 2011 providing an update on the process to develop
and implement a Recreation Management Plan for Blue Mountain.
4.4 District Owned Land Adjacent to Spirit Square
Staff report dated June 20, 2011 recommending that staff be directed to prepare
tender documents for the 224 Street enhancement project and solicit bid
proposals for the project and that the Corporate Officer be authorized to sign and
execute the Amendment to the Contribution Agreement.
4.5 Social Media Program
Verbal update and presentation by the Manager of Corporate Communications
5. CORRESPONDENCE
5.1
The following correspondence has been received and requires a response. Staff is
seeking direction from Council on each item. Options that Council may consider include:
a) Acknowledge receipt of correspondence and advise that no further action will be
taken.
b) Direct staff to prepare a report and recommendation regarding the subject matter.
c) Forward the correspondence to a regular Council meeting for further discussion.
d) Other.
Once direction is given the appropriate response will be sent.
Recommendation:
6. BRIEFING ON OTHER ITEMS OF INTEREST/QUESTIONS FROM COUNCIL
7. MATTERS DEEMED EXPEDIENT
8. ADJOURNMENT
Checked b
Date: +
Council Workshop
June 20, 2011
Page 3 of 3
Rules for Holding a Closed Meeting
A part of a council meeting may be closed to the public if the subject matter being considered relates to one
or more of the following:
(a) personal information about an identifiable individual who holds or is being considered for a position as
an officer, employee or agent of the municipality or another position appointed by the municipality;
(b) personal information about an identifiable individual who is being considered for a municipal award or
honour, or who has offered to provide a gift to the municipality on condition of anonymity;
(c) labour relations or employee negotiations;
(d) the security of properly of the municipality;
(e) the acquisition, disposition or exproprlation of land or improvements, if the council considers that
disclosure might reasonably be expected to harm the interests of the municipality;
(f) law enforcement, if the council considers that disclosure might reasonably be expected to harm the
conduct of an investigation under or enforcement of an enactment;
(g) litigation or potential litiggtion affecting the municipality;
(h) an administrative tribunal hearing or potential administrative tribunal hearing affecting the municipality,
other than a hearing to be conducted by the council or a delegate of council
(i) the receiving of advice that is subject to solicitor -client privilege, including communications necessary for
that purpose;
Q) information that is prohibited or information that if it were presented in a document would be prohibited
from disclosure under section 21 of the Freedom of Information and Protection of Privacy Act;
(k) negotiations and related discussions respecting the proposed provision of a municipal service that are at
their preliminary stages and that, in the view of the council, could reasonably be expected to harm the
interests of the municipality if they were held in public;
(1) discussions with municipal officers and employees respecting municipal objectives, measures and
progress reports for the purposes of preparing an annual, report under section 98 [annual municipal
report]
(m) a matter that, under another enactment, is such that the public may be excluded from the meeting;
(n) the consideration of whether a council meeting should be closed under a provision of this subsection of
subsection (2)
(o) the consideration of whether the authority under section 91(other persons attending closed meetings)
should be exercised in relation to a council meeting.
(p) information relating to local government participation in provincial negotiation_ s with First Nations, where
an agreement provides that the information is to be kept confidential.
MAPLE RIDGE
L 9ftish Columbia J
TO:
FROM:
SUBJECT:
District of Maple Ridge
His Worship Mayor Ernie Daykin
and Members of Council
Chief Administrative Officer
Alouette Rivers Hydrotechnical Model
EXECUTIVE SUMMARY:
MEETING DATE: June 20, 2011
FILE NO: E05-010-038
MEETING: Workshop
In response to a number of events and concerns by area residents to flooding in 2007, Council
established the Alouettte Rivers Flood Management Task Force. Based on the recommendations of
the Task Force, Council approved funding to develop a hydrotechnical model of the Alouette River
flood plain.
In late 2009, the District engaged Northwest Hydraulic Consultants to analyze the hydrology of the
rivers and develop a one-dimensional model of the river and a two-dimensional model of the flood
plain. The work has been completed. Attached to this report is the Executive Summary of the findings
of the hydrotechnical model.
Developing a model of the hydrology and hydraulics of the Alouette Rivers has provided a number of
insights regarding the rivers behavior. Like all hydraulic models, it is limited by the data that was
available but the model provides insights regarding the pattern of flood routing, locations of channel
erosion, deposition and constraints, areas for further assessments and the impact of infilling. Finally,
the model will be useful for emergency planning and response purposes.
Over the next few months, staff will review the report and develop a response for Council's
consideration. However, as the report confirms and as Council has approved proceeding with
removing accumulated sediment under the 224 Street bridge, staff are proceeding with the project
in 2011.
RECOMMENDATIONS:
This report is for information.
DISCUSSION:
a) Background:
Flood management issues in the Alouette River flood plains were publicized as a result of
significant storm events in 2007. While measurements indicated that rainfall through those
events was well above average and because interests and responsibility for flood hazard
management rests among many stakeholders, Council directed that a Task Force be
established to pursue strategies to manage or mitigate flood risks.
4.2
The Task Force met over a number of months to review the available information, identify
problems and issues, and develop options and recommendations. As a result of the review,
the Task Force identified six focus areas:
• River hydrology, hydraulics and flood plain mapping
• Operation and maintenance
• Flood response
• Flood proofing and protection
• Data collection and information sharing
• Flood plain management roles and responsibilities
The feedback from the Open Houses held by the Task Force indicated that there was general
agreement with issues identified by the Task Force. Issues identified included:
• the recognition of fish and wildlife values in the area
• a desire by residents for regular (on -going) river inspections
• removal of logs and debris is an on -going issue
• sediment removal is desired by some residents
• upstream activities (logging and development) is a concern to the residents
• emergency planning and response improvements could be improved
• residents have concerns regarding work done by other private property owners
• concern by area residents over privately constructed works (dykes)
• balancing of private interests and the effects of those interests on downstream
properties
• concern over the operation and adequacy of District facilities (culverts and
bridges)
As a result of its review and consideration of the issues, concerns and feedback from the
residents, the Task Force submitted a number of recommendations including that District
undertake a hydrotechnical model of the Alouette Rivers.
In 2009, Council approved funding of the undertaking to create a hydrotechnical model of
the Alouette Rivers. In particular, the District was interested in developing a greater
understanding of the river's hydrology and behaviour under flood conditions. As well, the
District was interested to reviewing its public infrastructure and if reduction of the associated
risks were possible. In particular, the sediment accumulation under the 224 Street bridge
(over the North Alouette River) was a significant concern.
Initially, the full work was to be done in partnership with BC Hydro, but divergent needs
dictated that the survey work could be partnered and that BC Hydro share available
hydrologic data. This resulted in the work starting later than anticipated. The District then
engaged Northwest Hydraulic Consultants who have performed extensive work on the rivers
to develop the model.
Report's findings
The Executive Summary of the work is attached to this report.
In general, the project reviewed and compiled a large number of data from various sources,
as well as reports including historic survey data and Water Survey of Canada (WSC) gauges.
As expected, both rivers are dynamic and have changed over the last century; with changes
more apparent on the smaller North Alouette system.
Major findings
The model identifies the flood routing of the rivers under flood conditions. The major findings
of the report include the following:
The North Alouette River is considered an active channel and many changes were observed
over time. Material from the upper watershed continues to pass through the system and a
pattern of aggradation was observed, although localised degradation is seen at constrictions
and at the WSC gauge. The North Alouette, being smaller (drainage area of 37.3 km2) and
unregulated, responds quickly to storm events, particularly large rain events.
The South Alouette River has been constrained and stable since the construction of the
Alouette Dam in 1926. The hydrologic regime of the South Alouette is dominated by spring
freshet type events which are dampened by the lake storage.
Although no clear trends are detectable at this time, they may become apparent in the future
as more data is collected and a reassessment of the climate and hydrologic data should be
made a decade from now.
There are significant challenges in modeling the North Alouette River. The North Alouette
River is a highly dynamic system, available hydrometric information was limited and there is
large uncertainty in the discharge curves at high water levels and flows. Furthermore, there is
known history of outburst floods resulting from the sudden release of a log jam and the
consultants have noted that these are a well-known process in the Pacific Northwest.
The report also identifies sites where erosion and deposition occurs and suggests that
because the river is dynamic and there may be adjacent vegetation to the rivers, on -going
inspections shall be carried out where feasible and appropriate, and that coordination
between the neighbourhood association, property owners and Maple Ridge staff continue.
The report also confirms that removing the sediment that is under the 224 Street bridge over
the North Alouette River as well as paying attention to erosion and deposition sites will be of
benefit. Northwest Hydraulics was requested to examine this and provide advice prior to
completing the final report to allow staff (if recommended) to proceed with advancing
necessary reviews and approvals to pursue the work in 2011.
The model also identified that new areas of the flood plain are wetted as a result of the filling
within the flood plain, particularly in regions adjacent to those that were raised. The raising
or infilling of land on the flood plain merely displaces the water, and relocates the flooding
problem to other properties. However, to address this issue, the report identifies a strategy
for flood management for the District to consider.
Finally, suggestions have been made over the years that that connecting the two rivers may
be able to reduce the flood hazard. The model suggests that building a connection between
the two rivers is a possible means of reducing flood levels in the North Alouette, and of
reducing the overall flood extent. However, it may be costly and significant effort will be
required to establish if this is a viable means of reducing flood hazard on the Alouette flood
plain. This would be a significant endeavor and much more analysis will be required.
The work of the consultant was presented to members of the former Task Force in mid -
January of 2011, as well as to get feedback to help validate the model. Internal meetings
were also similarly held to help validate the model.
Next Steps
Staff will be reviewing the findings of the report, particularly where there are policy
implications. While most of the recommendations can be accommodated in the work plan,
funding requests for work beyond 2011 will be submitted as part of the 2012 - 2016
Business Planning process. In addition, ongoing future data collection and future updates to
the model will also be considered.
As well, staff will consider the next steps for sharing the information with the public and
interested stakeholders.
b) Desired Outcome:
The desired outcome of this report is to inform Council on the findings of the hydrotechnical
model.
CONCLUSION:
Northwest Hydraulics Consultants has completed the work for the hydrotechnical model. The report
contains a number of insights and will be useful to the District in considering work related to the
Alouette Rivers, including policy development and emergency planning and response. The
responsibility and activities associated with flood plain management continues to be shared among
many parties and the interdependencies of these parties require a multi -disciplinary and multi -party
approach to strategies and solutions. The findings of the report will be shared with those.
Prepared by: Andrew Wood, PhD., PEng.
unicipal Engi
Approved Frank Quinn, MBA, PEn .
GM: Public orks elopment Services
Concurrence: J.L (Jim) Rule
C1ief Administrative Officer
/mi
North Alouette and South Alouette
Rivers' Assessment and
Floodplain Analysis
(Reference No. E05-011-029)
EXECUTIVE SUMMARY
MAPLE RIDGE
.w
District of Maple Ridge
June 2011
35292
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DISCLAIMER
This document has been prepared by Northwest Hydraulic Consultants Ltd. in accordance with
generally accepted engineering and geoscience practices and is intended for the exclusive use
and benefit of the client for whom it was prepared and for the particular purpose for which it was
prepared. No other warranty, expressed or implied, is made.
Northwest Hydraulic Consultants Ltd. and its officers, directors, employees, and agents assume
no responsibility for the reliance upon this document or any of its contents by any party other
than the client for whom the document was prepared. The contents of this document are not to
be relied upon or used, in whole or in part, by or for the benefit of others without specific written
authorization from Northwest Hydraulic Consultants Ltd. and our client.
Report Prepared By:
Tamsin Lyle, P.Eng
Senior Engineer
Report Reviewed By:
Monica Mannerstrom, P.Eng
Associate
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
Executive Summary
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TABLE OF CONTENTS
1 Introduction................................................................................................................ 3
2 Data Collection........................................................................................................... 4
3 Findings...................................................................................................................... 5
3.1 Geomorphology......................................................................................................... 5
3.2 Climate....................................................................................................................... 6
3.3 Hydrology................................................................................................................... 6
3.4 Flood History.............................................................................................................. 7
4 Modelling the Alouette Rivers.................................................................................... 9
4.1 Model Development.................................................................................................. 9
4.2 Modelling Objectives and Limitations...................................................................... 10
4.3 Description and Assessment of Modelled River Behaviour ..................................... 11
4.3.1 Flood Mechanism for March 2007 event......................................................... 11
4.3.2 Water Levels in Critical Reaches....................................................................... 11
4.3.3 200-Year Flood Extent....................................................................................... 12
4.3.4 Infilling of Floodway.......................................................................................... 13
4.3.5 Connecting the North and South Alouette Rivers ............................................ 13
5 Conclusions...............................................................................................................13
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
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INTRODUCTION
The Alouette Rivers are significant watercourses in Maple Ridge; they are a valuable and important
resource for the community and provide ecological and recreational opportunities. As with most
rivers, the flood plains experience typical challenges. Flood damage has occurred on the Alouette
rivers for well over a century. Over the past number of years residents have become actively involved
in seeking measures to manage and address flood related issues.
Historic photo of 224th Street, Source: City of Vancouver Archives dated Oct 1921
In 2007, extensive flooding prompted the creation of a multi -stakeholder Task Force that included
representatives from the municipality, provincial and federal agencies, universities and the
community at large. The objectives of the Task Force were to identify and compile information on
flood issues as well as to develop a strategy to manage and/or reduce the flood risk along the North
Alouette and South Alouette Rivers.
The Task Force recommended that a hydro -technical study be carried out to investigate and model
the water courses and to summarize the results in a report in order to improve the understanding of
the rivers and to help make informed future decisions, especially with respect to the District's
infrastructure.
This Executive Summary provides an overview of the project and the key findings of the model.
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
Executive Summary
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2 DATA COLLECTION
North Alouette River field survey (March 2010), NHC Photo
Data for the project was obtained from a number of sources, including geomorphic field surveys,
Water Survey Canada (WSC), the District of Maple Ridge, the Alouette Valley Association website and
BC Hydro. In order to develop the model, a Digital Elevation Model (DEM) was created from data
provided by the District and cross sectional data from BC Hydro; a re -survey of the rivers was not part
of the scope. As well, the development of hydrology inputs, such as peak flows and return periods
was required.
North Alouette River field survey (March 2010), NHC Photo
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3 FINDINGS
3.1 GEOMORPHOLOGY
The project included various geomorphic analyses to assess the characteristics of the rivers and
changes over time. General planform and cross-section patterns were examined using historic
survey data and airphotos. Localised changes in the rivers at the Water Survey of Canada (WSC)
gauges were examined by conducting a specific gauge analysis, or a review of how the relationship
between water levels and flows have changed over time.
Both rivers are dynamic and have changed significantly over the course of the last century; with
changes more apparent on the smaller North Alouette system. The regulation of the South Alouette
has arrested the natural expected changes to the channel.
South Alouette River (March 2010), DMR Photo
Infrastructure such as bridge sites can constrict flow and consequently cause degradation at flood
flows, which appears to be the case at the two gauge sites. Although, the cross-section comparison
is quite limited, there is reasonable evidence that some aggradation may be taking place in the lower
North Alouette study reach.
Overall, the North Alouette River can be considered an active channel and many changes were
observed over time in both planform and section. Material from the upper watershed continues to
pass through the study reach and a pattern of aggradation over the study area was observed,
although localised degradation is seen at constrictions and at the WSC gauge. Sites where erosion
and deposition was identified are presented as Figure 2.
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North Alouette River looking North downstream of MetroVancouver Park (March 2010), NHC Photo
The South Alouette River has a different regime and is generally stable. The construction of the
Alouette Dam in 1926 has generally arrested the development of the channel, as materials from the
upstream watershed are blocked by the dam, and large channel changing flows are rarely seen on
the river. In general, the channel is oversized for the post -regulation flows that are normally seen.
Current, historic and potential future climate for the Alouette Valley was examined as a part of the
technical analyses. Analyses were completed by looking at temperature and precipitation records for
Environment Canada climate gauges in the region. The watershed in general follows a coastal
regime, with cool wet winters, and relatively warm dry summers. Sixty years of climate data was
examined, and no detectable variation to precipitation or temperature were observed. The provincial
ClimateBC downscaling tool was used to estimate future climate in the region and in general the
climate models suggest that the winter season, when floods tend to occur, will become warmer and
wetter in the future. This suggests a potential for increased flood hazards for the region. Future
monitoring is recommended.
HYDROLOGY
Basic hydrologic analyses for the two WSC gauges on the North and South Alouette Rivers were
completed as a component of the project. The hydrologic regimes of the North and South Alouette
Rivers are distinct. The North Alouette, being smaller (drainage area of 37.3 km2) and unregulated,
responds more quickly to storm events, particularly large rainfall events. The much larger watershed
of the South Alouette (total drainage area of 234 km2) includes significant mountainous terrain and
the regulated Alouette Lake. The hydrologic regime of the South Alouette is dominated by spring
freshet type events which are dampened by the lake storage.
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Frequency analyses were completed for both rivers using historic data. In the case of the South
Alouette, a flow routing model was developed for the dam system. Estimates for the 200-year daily
events were 135 m3/s and 533 m3/s for the North and South Alouette respectively.
South Alouette River (March 2010), DMR Photo
An important note of caution is that all hydrometric information suffers from inherent limitations;
these become particularly relevant in a highly dynamic system such as the North Alouette River.
Throughout the course of the hydrologic and modelling investigations, possible inaccuracies in the
published flow data for the North Alouette gauge were identified. These include general
discrepancies associated with high flow estimates from extended rating curves, and irregularities in
lower and medium flows resulting from morphodynamic changes to the river in the vicinity of the
gauge. These data limitations, well recognized by WSC, are believed to have affected the accuracy
and outcomes of the numerical modelling.
As part of the project, historic flood events were reviewed. There have been a number of severe
floods recorded or estimated for the two rivers and the following tables (1 and 2) list historic high
flow events.
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
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TABLE 1
Largest Recorded Flow Events on the North Alouette River (1969 - Present)
Rank
Instantaneous Flow (m3/s)
Date
1
245*
March 11, 2007
2
162
February 24, 1986
3
157
January 18, 2005
4
154
November 6, 2006
5
147
October 16, 2003
6
140
November 11, 1990
7
132
November 13, 1998
8
126
January 4, 1984
9
124
July 11, 1983
10
118 December 26, 1980
*WSC estimate. A large slide that blocked the channel at approximately 11.5 km from the mouth
may have caused a flow spike when water broke through the slide blockage.
TABLE 2
Largest Recorded Flow Events on the South Alouette River (1984 - Present)*
Rank
Instantaneous Flow (m3/s)
Date
1
121
March 11, 2007
2
81.1
January 18, 2005
3
76.7
November 23, 1986
4
75.7
November 9, 1989
5
64.3
November 6, 2006
6
50.2
January 12, 1987
7
47.3
October 17, 2003
8
45.8
December 10, 2004
9
41.2
March 19, 1997
10
40.5
December 15, 1999
*Only events since regulation, which reflects current regime, are included.
Statistical analyses of historic flow data on the North Alouette were completed to determine long-
term trends in the data but no clear evidence of change over time is presently detectable. However,
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trends may become apparent in the future and it is important that flow data continue to be collected.
A reassessment of the climate and hydrologic data should be made every decade or so.
4 MODELLING THE ALOUETTE RIVERS
4.1 MODEL DEVELOPMENT
In order to build a reliable hydraulic model an eight step process is typically followed. Each of these
steps as it relates to the development of the Alouette Rivers model is discussed below:
1. Define Problem: Properly defining the problem, or the purpose of the model, is a key step in
the development process. For example will the model be used for large flood events, or for
evaluating localized flow phenomena? For the Alouette model, the project was well defined
during the scoping process with a primary focus on overall flow characteristics.
2. Collect Data: For a hydraulic model two key types of information are required: 1) topographic
information that describes the channel and floodplain; and, 2) hydraulic data that describes
the flow and water level conditions. For the Alouette model, channel bathymetry was
provided by BCHydro, who surveyed the river in 2008 for modelling flows much larger than
the 200-year flood. Over the course of the model development, some major limitations to this
data were uncovered for modelling the 200-year and lesser floods. The District of Maple
Ridge provided valuable topographic information of the floodplain. Hydraulic data was
primarily provided by the WSC, and unfortunately over the course of the project, significant
short -comings were found in this data that limited the accuracy of the model.
3. Develop Model: For the specified study area, NHC developed a hydraulic model of the two
rivers and floodplain. Initially we created a one-dimensional model of the river system using
a software package called MIKE11. A one-dimensional model, or a model that averages the
flow characteristics across the channel, is best suited for representing flow, in the confined
sections of the river, where flows remain within the river banks. However, it is difficult to
simulate complex overbank flooding, spills and bank breaching in a one-dimensional model.
These floodplain processes were modelled with a two-dimensional model using MIKE21 FM
(Flexible Mesh) software. Two-dimensional models can simulate multi -directional flow rather
than average flows across a section. The one and two dimensional models were then
connected using software called MIKEFLOOD. These software products are commonly used
in the industry.
4. Verify Model: The next step in model development involves checking that the model runs
properly and that the results make sense. For example, when inflows to the model are
increased, water levels and flood extents increase correspondingly. This step was completed
successfully, and in light of the model calibration and validation problems subsequently
encountered, was relied on more heavily than usual.
5. Calibrate Model: Model calibration is the process where using observed information (flows
and water levels) model parameters are adjusted so that the model outputs agree as closely
as possible with observed information. For the Alouette Rivers, the March 2007 event was
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selected as the calibration period as it was a recent high flow event with significant
anecdotal information regarding flow patterns across the floodplain. However, over the
course of the model calibration, numerous issues were discovered in the flow and water level
data for this period, and in the bathymetric data. Ultimately, the model was not calibrated to
existing data, and theoretical values for the model parameters were used.
6. Validate Model: After model calibration, ideally the model should be re -run for a separate
event, and the model tested against observed values. Due to data limitations, this step was
not completed.
7. Analyze Sensitivity: The assumptions used in the model, such as channel roughness should
be tested as part of model development. For the Alouette Rivers, the model sensitivity to
inflows, downstream water levels, channel roughness and floodplain roughness were all
tested and found to be relatively insensitive to minor changes in these parameters.
8. Run Model: Given the obstacles encountered during model development, only broad scale
assessments from the model runs are presented; further details are discussed below.
4.2 MODELLING OBJECTIVES AND LIMITATIONS
Over the course of the model development numerous issues with the input data were identified. In
particular, the bathymetric survey data provided by BCHydro was too sparse for the development of a
robust, calibrated model to represent flows in the 200-year and lesser flood range. Secondly,
numerous issues in the WSC water level and flow information were uncovered. Some of these issues
relate to the inherent difficult nature of flow monitoring, particularly on a dynamic river such as the
North Alouette, and some to unknown quantities such as the likely log/debris jam and subsequent
breach on the North Alouette River during the March 2007 event.
Logjam on North Alouette in upper watershed (March 2007), DMR Photo
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Regardless of its limitations, a model of the river system was created which helps to better
understand the behaviour of the rivers. As noted earlier, the key objectives of the study were to
determine the mechanism of flood events, improve the understanding of the hydrology of the rivers,
identify potential constraints such as bridge structures and determine areas for further study for the
District to explore the issues further which were not fully met by the model. Some basic results from
the modelling effort are presented below.
4.3 DESCRIPTION AND ASSESSMENT OF MODELLED RIVER BEHAVIOUR
4.3.1 FLOOD MECHANISM FOR MARCH 2O07 EVENT
On the North Alouette, the model identifies water going over bank on the right side of the river just
upstream of the 232nd Street Bridge. Next, water spills over bank on both sides of the river from
228th Street downstream to Park Lane. Over the simulation period, flood extents grow on both sides
of the river particularly between 228th Street downstream to what would be the intersection of 141st
Avenue. Meanwhile, water that is spilling overbank upstream of the 232nd Street Bridge flows
westward just north of 132nd Avenue. This is the approximate peak of the modelled flood extents.
On the South Alouette, limited overbank flow is seen at six locations on both sides of the river.
Because of the data limitations, direct calibration of the model was not achieved. However, the flood
extents of the modelled 2007 flood event were presented to Maple Ridge staff and to members of
the Alouette Valley Stakeholder group who verified and confirmed the general sequencing and
extents of the model results.
4.3.2 WATER LEVELS IN CRITICAL REACHES
The model identifies sections of the river that would benefit from more detailed examination. Major
constrictions, that result in elevated water levels were identified on both rivers and result primarily at
bridge sites, where the capacity of the channel is reduced. Upstream water levels were also raised
on both rivers as a result of dike confinement, where dikes on both sides of the river reduce the
conveyance of the channel.
In particular, it would be beneficial to remove the sediment from under the 224thStreet Bridge and
eventually from other deposition sites identified in Figure 2. Recognizing that the river banks may be
privately owned, the District may wish to inform the property owners regarding the availability of this
information.
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s
North Alouette River (at 224th St Bridge) March 2010, NHC Photo
In light of the dynamic nature of the river and adjacent vegetation and land uses, it is recommended
that on -going inspections to locate areas of increased erosion or logjams be carried out where
feasible and appropriate, and that coordination between the stakeholder group, property owners and
Maple Ridge staff continue.
Debris accumulation along South Alouette River (March 2010), DMR Photo
4.3.3 200-YEAR FLOOD EXTENT
While the project was not intended to revise the current BC Ministry of Environment flood plain
mapping, the updated model generally agrees with the extent of the 1990 flood plain. Figure 3
highlights the extent of the flood plain under a potential 200 year flood for representation purposes
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
Executive Summary 12
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northwest hydraulic consultants
only. It is important to note that the accuracy of the depths cannot be confirmed due to the data
limitations and river dynamics described.
As part of the project, two key scenarios were examined: 1) the impact of infilling the floodway; and,
2) the historic concept of connecting the North and South Alouette Rivers.
4.3.4 INFILLING OF FLOODWAY
The model was modified to identify the impacts of infilling of the flood plain by raising 50 percent of
the land within the 25-year floodway. The infill areas were selected at random on both the North and
South Alouette flood plains. Using the modified model, changes to the water levels at the gauges
under higher frequency events were examined as well as the inundation areas.
The model results indicated that new areas of the flood plain would be wetted as a result of the
infilling, particular in regions adjacent to those that were raised. The raising or infilling of land on the
flood plain displaces the water, and relocates the flooding problem to other properties.
However, in order to ensure that displacement from infilling does not occur or is minimized, it is
recommended that that the District consider as a strategy for flood management that `new or
upgraded flood protection structures do not adversely increase the overall flood hazard'.
Furthermore, a no -net adverse impact flood level policy should also be implemented for future
developments on the flood plain, including any infilling or upgraded diking projects.
4.3.5 CONNECTING THE NORTH AND SOUTH ALOUETTE RIVERS
Over the years, suggestions have been made that connecting the two rivers would reduce the flood
hazard. In order to assess if, at a conceptual level, establishing a connection between the two rivers
in the vicinity of 232nd Street would alleviate flood conditions on the North Alouette River, a link
channel that connects the two rivers was modelled.
This scenario suggests that building a connection between the two rivers is a possible means of
reducing flood levels in the North Alouette, and of reducing the overall flood extent. However, the
scenario presented makes some very broad assumptions, may be costly and have significant
environmental impact. Therefore, more effort will be required to establish if this is a viable means of
reducing flood hazard on the Alouette flood plains. The results do however suggest that further
study is warranted should Maple Ridge choose to explore this.
CONCLUSIONS
The North and South Alouette rivers form an important community resource within Maple Ridge. The
rivers behave hydraulically differently, but are linked in the flood plain. In particular, the flow and the
channel of North Alouette River are dynamic, making accurate modelling a challenge. The South
Alouette River is much more stable and is controlled by BC Hydro operations.
Flood damage has occurred on the Alouette rivers for well over a century. Over the past number of
years residents have become actively involved in seeking measures to manage and address flood
related issues. The hydrologic analyses concluded there is no evidence that flows to date have
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
Executive Summary 13
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northwest hydraulic consultants
increased. However, periodic reassessment of the climate and hydrologic data is recommended to
determine the variability and impact of climate change.
In terms of flood events, there are other factors such as temperature, antecedent conditions and
events such as logjams that play a role in the hydrology and hydraulics of extreme flow events on
the North Alouette River. The South Alouette River on the other hand, is much more stable, as at is
controlled to a very large degree by BC Hydro's operations.
Developing a model of the hydrology and hydraulics of the Alouette Rivers has provided a number of
insights regarding the rivers' behaviour. While the accuracy of the model developed was limited by
the data available, understanding has been gained regarding the pattern of flooding, locations of
channel erosion and deposition, constrictions, areas for further assessments and the impact of
infilling. Given the model accuracy resulting from available input data, the District may wish to
consider further work, such as channel surveys and flow monitoring to improve the overall quality of
the model.
North Alouette and South Alouette Rivers' Assessment and Floodplain Analysis
Executive Summary 14
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4
MAPLE RIDGE
District of Maple Ridge
Deep Roots
Greater Heights
TO: His Worship Mayor Ernie Daykin MEETING DATE: June 20, 2011
and Members of Council FILE NO:
FROM: Chief Administrative Officer MEETING: Workshop
SUBJECT: Blue Mountain Update
EXECUTIVE SUMMARY:
A Recreation Management Plan was established for Blue Mountain beginning in 2001.
Implementation stalled in part due to lack of funding. Recently, the Ministry of Natural Resources
has allocated some funding to plan and develop staging areas to provide improved access to Blue
Mountain in a manner that is less disruptive to neighboring residents. The acquisition of funding has
provided an opportunity to pull stakeholders back together to input on the location of the staging
areas and to continue discussions on the implementation of the plan.
RECOMMENDATION:
No resolution is required.
DISCUSSION:
a) Background Context:
The Ministry of Tourism, Sports and the Arts reactivated the management plan for Blue
Mountain in 2003, and tasked Mike Peters with its implementation. Since then, Ministry
titles have changed and Mr. Peters is now with the Ministry of Natural Resources, however
Mr. Peters continues to retain responsibility for the implementation of the plan.
Over the years, the District has participated in stakeholder and planning meetings, and has
expressed interest in:
1. Supporting the expansion of Metro Vancouver's Kanaka Creek Park,
2. Protecting the vista -shed of Alouette Lake from the east shore,
3. Addressing access and management of public recreation activities and related issues
such as environmental impacts and wildfire risk.
Mr. Peters advised that data gathering and identification of trail routes for each type of use
was completed and mapped as a first step. The second area of focus was to confirm forestry
tenures. The most recent group to enter into an agreement has been Katzie First Nation,
who signed a Forest and Range Consultation and Revenue Sharing Agreement on April 26,
2011. Prior to this, a Woodlot License was issued to Kwantlen First Nation (KFN) and to a
private operator. Mr. Peters noted that KFN continues to express interest in their original
request for a Community Forest Agreement which has been unsuccessful to date. The
District of Maple Ridge had entered into a Memorandum of Understanding (MOU) pertaining
to this application in 2007, and extended it in 2009. The MOU expired at the end of October
2010.
4.3
Mr. Peters recently reported that Blue Mountain received $35,000 to plan two staging areas
in 2011, and will receive an additional $100,000 in 2012 to develop the areas that are
identified as the most ideal locations. The goal is to establish one staging area for motorized
vehicles on Crown Land in a location that will remove this access from occurring at 256tn
Street. The other staging area will be planned for non -motorized vehicles on Crown Land in a
separate location from motorized access. Stakeholder groups have been informed that this
planning will occur this year, and groups will be invited to input to the planning process.
According to Mr. Peters, the recent acquisition of funding has provided a trigger to bring
stakeholders back together to continue discussing implementation of the Blue Mountain
Plan and it is anticipated that discussions on the appropriate recreational use and
management of Blue Mountain will continue, following the discussions on where to locate
the staging areas.
b) Desired Outcome:
The desired outcome is to ensure planning for Blue Mountain is a collaborative process that
involves all stakeholders in a manner that mitigates issues and maximizes benefits to all
concerned.
c) Strategic Alignment:
Participation in Blue Mountain planning aligns with Council's direction to develop and
maintain strong, positive working relationships with stakeholders, neighbhours and other
levels of government while encouraging active and healthy lifestyles among citizens through
the provision of a variety of exceptional recreational activities.
d) Citizen/Customer Implications:
A number of groups with diverse interests are participating in planning for Blue Mountain.
The implications for each group ranges from recreation access to economic benefits to
environmental concerns. It appears that all groups' interests are being considered within the
planning process being overseen by the Ministry of Natural Resources.
CONCLUSIONS:
The process to develop and implement a Recreation Management Plan for Blue Mountain has been
a lengthy one, and although the progress has been incremental, it does appear to be progressing.
The allocation of funding to plan and develop staging areas has provided the impetus to pull
stakeholders back together to continue this work. The District of Maple Ridge will continue to remain
in contact with the Ministry to receive regular updates and to participate in all opportunities to
provide input to the plan and its implementation.
Prepa
General Ma
Concurrence: J.. (Jim) Rule
Chief Administrative Officer
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mmunity Development, Parks and Recreation
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Deep Roots
Greater Heights
TO:
FROM:
SUBJECT:
District of Maple Ridge
His Worship Mayor Ernie Daykin MEETING DATE:
and Members of Council FILE NO:
Chief Administrative Officer MEETING:
DISTRICT OWNED LAND ADJACENT TO SPIRIT SQUARE
June 20, 2011
Council Workshop
EXECUTIVE SUMMARY:
At the May 30, 2011 Council Workshop, Council passed a resolution "That staff be directed to
prepare a detailed design for the first phase of the concept plan for Councils consideration by June
21, 2011, in order to take advantage of the remaining eligible Provincial/Federal funding of
approximately $400,000 from the 224th road improvement project. This phase will need to be
completed by October 31st 2011 to be eligible for this funding opportunity"
A report on the strategic alignment, financial and economic implications related to the future use of
the balance of this site, will be brought forward in a separate report at a future date.
RECOMMENDATION(S):
That staff be directed to prepare the tender documents for the 224th Street enhancement project
and solicit bid proposals for the completion of this project from qualified contractors for approval by
July 21, 2011 to ensure that the project is completed by October 31st 2011, which is a condition of
the grant funding; and
That the Corporate Officer be authorized to sign and execute the Amendment to the Contribution
Agreement dated January 14, 2010.
DISCUSSION:
a) Background Context:
The above recommendation follows a public consultation process where staff were directed
to ask residents and businesses: (A) If they supported Family Themed Public Space or (B)
Mixed use commercial development on this site adjacent to Memorial Park. Council was
provided with an update on the comments which indicated a high level of support for option
(A) Family Themed Public Space.
Parks and Engineering Staff working with a consultant have completed the detailed design
for this project. Other site improvements such as irrigation, drainage, seeding and low level
landscaping have been added as part of the project, to return the site back to a usable and
functional condition once the hard surfacing has been completed. These items have been
priced separately as they do not meet the criteria of the Federal /Provincial grant funding,
and will be installed as part of the tender and funding will be dealt with in the next Financial
Plan Amendment.
4A
Staff have also met with festival group representatives including, the Farmers Market,
Caribbean Festival, Canada Day, Downtown Maple Ridge BIA, Community Festival Network,
Mountain Festival and the Christmas Festival, to ensure that the proposed design met with
the approval of the wide range of events that currently occur in Memorial Peace Park. The
representatives who attended this meeting are supportive of this initiative, and offered
thoughtful suggestions on the design.
It should be noted that staff have received approval to amend the original Building Canada
Fund Agreement (#25890) for this work to proceed and recommends that the Corporate
Officer be authorized to sign and execute this agreement. (Amendment to the Agreement
Attached).
b) Desired Outcome(s):
The proposed project will take advantage of the remaining funds from the 224th Street road
infrastructure project to construct a loading and unloading area that will also support current
and future events on 224th Street and in Memorial Peace Park and Spirit Square.
c) Strategic Alignment
The site is currently designated town center commercial in the official community plan, and is
zoned as P1 which allows for Public Park and public elementary development.
d) Citizen/Customer Implications:
The respondents from the previous survey in this regard are supportive of this site being
used as family themed public space. The community festivals representatives who reviewed
the concept plan for this site have also expressed their support for this initiative.
e) Interdepartmental Implications:
Engineering, Planning and Parks Staff have all been involved in the project.
f) Business Plan/Financial Implications:
The portions of the project associated with the Infrastructure grant are estimated to cost
$390,000.00. The other improvements to make the site usable and functional, such as
drainage, irrigation and seeding of the grassed area are estimated to cost $70,000.00, and
this funding will be dealt with in the next Financial Plan Amendment.
g) Alternatives:
An alternative may be to leave the site as is, however this is not recommended as the
Provincial/Federal portions of the road improvement grant would no be utilized.
CONCLUSIONS:
The concept plan was strongly supported by the community event representatives who met with staff
and time is of the essence to complete this project.
Prepared ,by: `�a vid Boag
Director, Parks and Facil
�4 - 7� -
prepare by: Andrew Wood
Municipal Engineer
7
Approved by. Kelly ift
General anager, Community Development, Parks and Recreation
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Appro d by: Frank Quinn
General Manager, Public Works and Development Services
�y: Pa Gill
Gqfieral Manager, Corporate and Financial Services
1
Concurrence: J.L. (Jim) Rule
Chief Administrative Officer
Attach.
• Detailed Design
9 Amendment to the Contribution Agreement, January 14, 2010
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CANADA-BRITISH COLUMBIA
BUILDING CANADA FUND — COMMUNITIES COMPONENT
AMENDMENT TO THE CONTRIBUTION AGREEMENT DATED
JANUARY 14, 2010
BETWEEN
Her Majesty the Queen in right of the Province of British Columbia, (the "Province")
represented by the Minister of Transportation and Infrastructure
District of Maple Ridge (the "Recipient")
for the Downtown Core & Utility Rehabilitation
Project #25890
The following amendments are made to the above noted Agreement:
Schedule A: PROJECT INFORMATION
A.2 This project will address current deterioration and substandard infrastructure on
Lougheed Highway and 224th Street while expanding capacity to support future
density in both residential and commercial sectors. It will support sustainable
growth and ensure active accessible transportation options are available to
encourage less automobile use.
This project will resolve aging infrastructure including:
• sanitary and storm sewer drainage systems;
• roads and sidewalks;
• water distribution system (to increase capacity); and
• expanding the fibre optic network into the downtown area.
is hereby deleted and the following substituted:
A.2 This project will address current deterioration and substandard infrastructure on
Lougheed Highway and 224th Street while expanding capacity to support future
density in both residential and commercial sectors. It will support sustainable
growth and ensure active accessible transportation options are available to
encourage less automobile use.
This project will include:
• sanitary and storm sewer drainage systems;
• roads and sidewalks;
• water distribution system (to increase capacity);
• expanding the fibre optic network into the downtown area;
• additional vehicle access and egress to 224'I' Street;
• additional commercial loading and loading areas;
• expanded transit facility area;
• installation of bicycle lockers and racks;
• improve underground utility infrastructure (electricity, fire hydrant, road
drainage);
• installation of street lighting; and
• landscaping, benches and garbage receptacles.
To signify agreement with this amendment, please sign below and return the original to the
Ministry of Transportation and Infrastructure.
THE PROVINCE OF BRITISH COLUMBIA Date
Ministry of Transportation and Infrastructure
I agree to the above -noted amendment to the agreement.
District of Maple Ridge
Authorized Signatory
Name and Title
Date