COLLIERY DAMS
TECHNICAL COMMITTEE
STATUS UPDATE
Background
Mandate of Technical Committee:
On October
21, 2013 the City of Nanaimo struck the Technical Committee with
a mandate to focus
on outcomes
that only involve remediating the existing dams, using the following
phased approach:
• Phase 1: Review the existing data and direct additional data collection as necessary.
• Phase
2: Develop option(s) for remediating the existing dams that will
satisfy the
requirements of
the Dam Safety Section of the Ministry of Forests, Lands and Natural Resources.
• Develop
plans for short-term physical alterations to the dams in 2014 to
provide the
necessary time
to carry out the long-term strategy (if required).
Composition of Technical Committee:
The Committee
is comprised of representatives of the City; Snuneymuxw First
Nation; the Colliery
Dams Park
Preservation Society; and engineering firm Golder
Associates. Committee facilitator
Katherine Gordon
was appointed on November 26. Both Golder Associates and Gordon
were
appointed by
the Committee after review of a number of candidates.
Katherine Gordon
will act as the contact person in relation to any questions about
these updates or
the work
of the Committee.
Role of Technical Committee:
The Committee
is tasked with making viable recommendations on rehabilitation
options to be
reviewed by
the City, Snuneymuxw First Nation and the Dam Safety Section. Those
recommendations are
to be made by February 28 2014 to the Executive Committee, which is
comprised of
City senior staff and Snuneymuxw advisors directed by the Chief. The
Executive
Committee oversees
the Technical Committee and if necessary provides guidance and
advice to the
Technical Committee.
Decision-making process:
In due
course the Executive Committee will provide commentary
and recommendations to the
Policy Group
(Mayor and Council/Snuneymuxw Chief and Council) for consideration
and discussion.
As owner
of the dams, City Council must make the final decision on
which rehabilitation option to
pursue and
any short-term mitigation options required before
permanent remediation takes place.
The parties
involved at the table agree that this is a fair, credible process
to follow.
Meetings of the Technical Committee
The Technical
Committee has met twice, on December 5 and 13, and three meetings
are scheduled
for January
to discuss communications and risk assessment approaches
and technical options being
developed by
Golder Associates for committee consideration. Representatives of the
Dam Safety
Section attend
meetings in order to ensure they are fully informed and are able
to contribute to the
progress of
technical discussions.
Objective of the Technical Committee
The Committee
has agreed on the following overarching objective for its work:
Development of
an environmentally minimally invasive, cost- and
time-effective solution while
satisfying required
safety standards - i.e. a solution that addresses:
• The safety
of downstream residents and workers;
• Dam Safety
Section requirements;
• The respective
objectives of the City, Snuneymuxw First Nation, the Colliery
Dam Park
Preservation Society
and the community;
• Environmental concerns,
including fisheries habitat and ecology;
• Cost-effectiveness; and
• Having a
timely permanent solution in place in 2014 if possible, but no later
than 2015, with
shorter term
mitigation in place if required in 2014.
Approach to Development of Rehabilitation Options
Investigation work
The Committee
is combining work on Phases 1 and 2 of its assigned tasks. Golder
Associates is in the
process of
reviewing the existing data and collecting additional data
as required. The Committee has
provided Golder
with copies of historical and other relevant documents and reports
and City staff are
working with
Golder to provide whatever support is required in order to conduct
any additional physical
site investigation
of the Lower and Middle Dams.
The physical
site investigation involves a limited geophysical examination of
the two dams that will take
place during
the week of January 13. This is a non-invasive way to survey a large
area of the dams with
hand-held equipment
that can be used in areas that are difficult to access
with conventional drilling
equipment and
minimize disturbance to the dams and watercourses.
The objectives
include providing information related to the internal dam fill
zoning of the two dams,
gathering information
about the water table, underlying foundations and reinforcement
(such as rebar)
within the
concrete wall, collect information which may help to
establish whether a low-level-outlet may
exist, and
gather any other geophysical information, including
seismic velocities, that will help in
developing suitable
remediation options.
The work
will be carried out on land, is non-invasive and is not expected to
have adverse
environmental impacts
as the radar and seismic signal sources are all very low energy.
However, it
may be
necessary, during one day of seismic surveying, to limit
public access in order to minimize
vibration noise
during the seismic recordings. If this is the case, notices will
be posted at entrances
to the
Colliery Dams Park and on the City of Nanaimo website, as well
in local newspapers.
A second
phase of site investigation will likely take place in the first
half of February and involve
investigative drilling
in the embankments and concrete core of the dams. The geophysics
work may
provide information
that will influence the scope of the drilling.
Risk assessment
At the
same time, Golder has adopted an approach which includes the revised
(2013) Canadian Dam
Association Dam
Safety Guidelines to satisfy Dam Safety Section requirements. This
approach applies a
risk assessment
methodology to the development of satisfactory rehabilitation
options. Dam Safety
Section staff
have indicated that they are willing to work with this new approach.
It is an approach that
both governments
and industry are increasingly moving towards in developing
cost-effective strategies
to address
risk issues.
Over the
next few weeks, Golder will be undertaking a risk assessment of the
dams and concurrently
developing technical
remediation options. The preliminary work will be presented to
the Committee in
late
January.
Looks promising so far. Thanks for the update.
ReplyDeleteD. Cutts
President DDAG
Thanks for the update.
ReplyDeleteIt sounds like there is a good will on both sides of the "fence"
(The City and Snuneymuxw/Harewood Nations).
As long as people are willing to tlak, there is a room for a reason,
and that is good for the park, lakes and people enjoying this one of a kind place.
Slawomir aka *Swav* (Harewood Resident)