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1. INSTALLATION
OF INLET CONTROL DEVICES INSTALLATION DES DISPOSITIFS DE CONTRÔLE DU
DÉBIT |
That Council direct City Construction Inspection staff to develop
and implement protocols by January 2010 that require a professional engineer to
certify that all required Inlet Control Devices are properly installed and
inspected prior to permitting a new storm sewer to connect to the City’s
existing storm sewer system.
Recommandation DU Comité
Que le Conseil dirige le personnel
des inspections de chantiers de construction de la Ville d’élaborer et mettre
en œuvre d’ici janvier 2010 des protocoles qui requièrent que des ingénieurs
certifient que tous les dispositifs de contrôle du débit sont correctement
installés et inspectés avant de permettre qu’un nouvel égout pluvial soit
raccordé au réseau d’égouts pluviaux actuel de la Ville.
1.
Coordinator,
Planning and Environment Committee report dated 20 October 2009
(ACS2008-CCS-PEC-0024).
20 October 2009 / le 20 octobre 2009
Submitted by/Soumis par : Carole Langford,
Committee Coordinator / Coordonnateur du comité
Contact Person/Personne ressource : Carole Langford, Committee
Coordinator
City
Clerk’s Branch/Direction du greffe
(613)
580-2424 x28934, carole.langford@ottawa.ca
SUBJECT:
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OBJET :
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That
Council direct City Construction Inspection staff to develop and implement
protocols by January 2010 that require a professional engineer to certify that
all required Inlet Control Devices are properly installed and inspected prior
to permitting a new storm sewer to connect to the City’s existing storm sewer
system.
Que
le Conseil dirige le personnel des inspections de chantiers de construction de
la Ville d’élaborer et mettre en œuvre d’ici janvier 2010 des protocoles qui
requièrent que des ingénieurs certifient que tous les dispositifs de contrôle
du débit sont correctement installés et inspectés avant de permettre qu’un
nouvel égout pluvial soit raccordé au réseau d’égouts pluviaux actuel de la
Ville.
At
its meeting on 13 October 2009, the Planning and Environment Committee received
a presentation by staff regarding the modeling for water levels in the Carp
River. After extensive discussion, the
Committee approved the following motion brought forward by Councillor Feltmate:
Whereas the City of Ottawa’s Design
Guidelines has been shown to provide a high degree of protection against
flooding during storm events, and
Whereas Inlet Control Devices are one of the measures that City’s Design Guidelines utilizes to prevent against basement flooding, and
Whereas in new developments or city projects,
where projects are still under construction, it is prudent to ensure that Inlet
Control Devices are installed as early as possible;
Therefore be it resolved that City Construction Inspection staff develop and implement protocols by January 2010 that require a professional engineer to certify that all required Inlet Control Devices are properly installed and inspected prior to permitting a new storm sewer to connect to the City’s existing storm sewer system.
Planning and Legal
Services staff were in attendance at the meeting and are aware of this motion.
The installation of Inlet Control Devices is a measure that reduces the likelihood of basement flooding and other flooding related damage from occurring during a significant rain event. Accordingly, the proper installation of Inlet Control Devices is a recommended risk management measure.
There are no financial implications.
Document 1 – Carp River Model Update Presentation (Previously
distributed and held on file.)
Document 2 – Draft Minute Extract of the Planning and Environment Committee meeting on 13 October 2009
Following approval of the report, Planning staff to implement accordingly.
document
2
Update:
modeling for water levels in the Carp River with updated data
MISE À JOUR DE la modélisation des niveaux d’eau de la rivière Carp avec
des données à jour
Stittsville-Kanata west (6)/ouest, kanata south/sud (23)
Written correspondence was received
on 13 October 2009 from Ted Cooper and is held on file with the City Clerk.
Mike Wildman, Manager, Development
Review (Suburban), provided a PowerPoint presentation, which is held on file
with the City Clerk. Don Herweyer,
Project Lead for the Kanata-West Environmental Assessments and Don Moss,
Professional Engineer, Greenland International accompanied him. Also in attendance was Mr. Leman, a
representative of the Mississippi Valley Conservation Authority (MVCA) attended
to assist in answering committee’s questions.
By way of introduction, Mr. Wildman
informed Members Mr. Moss’ employer; Greenland International specialises in
environmental management, flooding impact, stormwater and water quality. He has been assisting the City throughout
the Third Party Review (TPR) and continues to assist in a number of exercises,
including the model keeper role.
In response to questions from
Committee Members, staff supplied the following responses:
· A
model begins with a design drawing, with various elevation drawings that are
inserted into the model, and then they display alternate effects on a
stormwater pond.
· Build
up of sediment can occur over time on the bottom of a pond, causing water
levels to rise. As with all of the City’s maintenance structures, a maintenance
schedule is in place for stormwater ponds with regular monitoring to identify
ponds that may need cleaning or high water levels caused by sediment build up.
· Set
flood levels for flood mapping is provincially mandated and states that if a
summer rainfall is used, it is assumed that it is uniform over the entire
watershed.
· In
the original study of the Carp River watershed and sub-watershed, spring melt
was incorporated into the scenario.
· During
the TPR, various locations were reviewed to determine the most effective and
efficient placement of monitoring equipment. Presently, there are five City
rain gauges to calibrate the radar data. Going forward two more gauges will be
in operation within the Carp area, along with the current one located at
Richardson Side Road. Poole Creek and the upper end of the Carp River were two
additional proposed locations.
· The
gauges currently being installed, including the one in the Carp River, measure
both velocity and water levels, the gauges used in the past only measured water
levels. A reason for switching to a different type of gauge was that electronic
components were being damaged by sediment in the river. The initial finding of
this alternate equipment has been positive and it is the belief that it will
help resolve some of the problems being faced.
· Velocity
measurements are important when trying to establish features within the models,
such as timing of flow entering from various points into a corridor. If water
flows reach the point of velocity of zero, the result is the creation of a
lake.
· If
the proposed future model were run, TPR identified it would have higher water
levels through the corridor. Subsequently, as part of the model keeper role,
continuous work is being done, including the investigation of widening
alternatives, a mandate within the City’s recommendations.
· The
Glen Cairn Pond did not overflow, high water marks in the pond were staked at
95.2, the rim of the pond is at 96; the pond still had a lot of capacity during
the storm. Water levels were staked from Eagleson Road down through Glen Cairn
to the Village of Carp.
· The
current model begins with the Glen Cairn Facility and does not model upstream
from the facility. The upstream work was done independently with another
consultant in 2003.
· There
are two levels of models that are created for this type of studies, the
planning level model in which all that is looked at is what is going to flood
the Carp River and the corridor and the model which looks at roads and sewers
going through new developments.
· The
models reviewed under the TPR were specifically designed to ensure that the
corridor would not have higher water levels than the existing model. The new development that was proposed for
Kanata West took this model and created a second series of models to look at
roads and sewers.
· When
the Glen Cairn community and its facility were developed, they did not have
computers or the technology that exist today. Currently the City’s design
standards are better or exceed most of the provincially mandated ones.
· When
updating the model, the stormwater management facilities and the drainage areas
were added. The consultants, who produced the subdivision, did a hydraulic
analysis that runs through the pipe network.
· The
corridor widening and retrofit proposed for the Carp River restoration plan is
set to approximately 500 metres downstream to Richardson Side Road.
· 27
clusters were identified in the flooding areas, among them Westwood, west of
Stittsville, the majority of the rainfall fell on Amberwood area; however, the
Westwood area suffered worst flooding effects. Instances such as this were
reviewed and investigated by Mr. Newall’s staff. Some of the areas had a number
of different occurrences that caused flooding, including not experiencing a
major system, no control devices, and others were due to backwater valves not
working.
· The
Glen Cairn Facility was not reviewed originally. In light of what happened in
July, they took the opportunity to study the Glen Cairn neighbourhood, looking
at road patterns and other features. The Glen Cairn Facility is unique, the City’s
stormwater management facilities was originally a conservation authority
Facility. The Glen Cairn Detention Basin is owned by the conservation
authority.
· The
Glen Cairn Facility was originally constructed with the assistance of the
Township of Goulbourn and the MVCA acquired the property to have the facility
constructed. It is unclear whether or not there was an agreement with the
municipality with respect to additional work.
· The
facility was constructed according to the standards that were appropriate in
mid-1970s; it was designed to accommodate the 100-year storm from the area
upstream of it.
In summation, Mr. Wildman ensured
that the Carp is performing as it was intended to function in the original
models and in the TPR.
Moved by P. Feltmate
Whereas the City of
Ottawa’s Design Guidelines has been shown to provide a high degree of
protection against flooding during storm events, and
Whereas Inlet Control Devices are one of the measures that City’s Design
Guidelines utilizes to prevent against basement flooding, and
Whereas in new developments or city projects, where projects are still
under construction, it is prudent to ensure that Inlet Control Devices are
installed as early as possible;
Therefore be it resolved that City Construction Inspection staff develop
and implement protocols by January 2010 that require a professional engineer to
certify that all required Inlet Control Devices are properly installed and
inspected prior to permitting a new storm sewer to connect to the City’s existing
storm sewer system.
CARRIED
That the Planning and
Environment Committee receive a presentation on the above-noted subject.
RECEIVED
DIRECTION TO STAFF
Infrastructure Services and Community Sustainability staff to provide Councillor Feltmate with a report showing when the Glen Cairn pond was cleaned out.