Chapter A - Introduction - City of Pickering

COMMENT
MUNICIPAL COMMENTS AND RESPONSES
CITY OF PICKERING – OCTOBER 22, 2012
Chapter B – Water Resources
TABLE 1: COMMENTS AND RESPONSES WITH REVIEW AGENCIES (EXCLUDING TRCA)
RESPONSE
REPORT CHAPTER
AND SECTION
HIGH LEVEL Comments
The 2012 Duffins Creek Hydrology Update will be completed shortly. We expect that the Seaton
Landowner Group (SLG) will incorporate the results and recommendations from the hydrology
update. With regards to applicable stormwater management controls, specifically quantity
control, based on initial results quantity control will be required for all sub-watersheds within
Seaton (including un-named tributaries of the West Duffins, and Whitevale Creek). The only
areas not requiring quantity control are those which drain directly to the main branch of the West
Duffins Creek. Until such time as the Seaton specific quantity control requirements are made
available, the SLG shall utilize the 2 to 100 post to pre level of controls as the minimum criteria.
The City’s “Stormwater Management Design Guidelines” outline the design requirements for
stormwater management facilities. We expect that SLG will meet the objectives and design
requirements as outlined in the City’s design guide, which is consistent with Policy 11.45 of
Amendment 22 to the Pickering Official Plan (Seaton Conformity OPA).
There are watercourses that have no current defined channel, have existing erosion issues, or
are classified as gully systems. We have identified 17 watercourses of concern (Appendix C),
where erosion may potentially occur, regardless of the level of stormwater management
controls. We would like to work proactively with representatives from TRCA, MNR, and the SLG
to address this issue.
Greater coordination between the SLG and the Region relating to stormwater management is
recommended. We understand that Regional infrastructure is to drain into future City
stormwater management facilities, as needed and where technically feasible. Therefore, the
Region’s stormwater management strategy should be incorporated within a revised MESP.
The results of the 2012 Duffins Creek Hydrology Update have been incorporated into Chapter B, Section B5.1. It should be noted that
at time of issuance of these comments, the 2012 Duffins Creek Hydrology Update was not complete. At time of issuance of the MESPA,
the 2012 Duffins Creek Hydrology Update technical analyses were complete and the City provided flows, storage and discharge
recommendations for inclusion in this MESPA.
The MESPA references the City’s “Stormwater Management Design Guidelines” in Chapter B Section 6.4 and in Chapter J Section
2.0.
Each of the 17 watercourses of concern has been reviewed and a response provided below. This has been incorporated into the
MESPA in Chapter B Section 10.5.
Coordination with the Region with respect to SWM facilities and Regional road drainage has been undertaken through the NFSSR
design process. Each NFSSR will identify which Regional Roads will drain to which SWM facility and which roads require on-site SWM
controls. This has been included in the revised Annotated Table of Contents for the NFSSRs which is presented in Chapter J,
Appendix J2.
Chapter B, Section
B5.1
Chapter B Section 6.0
and Chapter J Section
2.0
Chapter B Section
10.0
Chapter J, Appendix
J2
Part A – General Comments
COMMENT MESPA RESPONSE (December 2011) CITY RESPONSE (October 2012) RESPONSE
Hydrologic Modelling
A detailed review of the hydrologic modelling included in the MESP by City
staff and TRCA have revealed deficiencies in the overall methodology,
parameters and assumptions that went into the modelling analyses and
subsequent stormwater management recommendations in the MESP. Staff
recommends that the Duffins Creek 2002 Model (Aquafor Beech) be updated
to include the more specific information from the Seaton area utilizing the
same methodology for determining the parameters (CN*, time to peak, area,
subcatchments, etc.) and calibration procedure in order to recalibrate the
model using eight more years of streamflow and rainfall data (from 2002 to
2010).
An update to the hydrologic model has been undertaken
as per discussions at numerous technical meetings with
TRCA and the City throughout 2011. Based on these
discussions, revisions have been made to both the
existing and future conditions models. Models are
discussed and results presented in Chapter B5.0.
The City and TRCA are currently in the process
of completing the “2012 Duffins Creek
Hydrology Update”, it is the City’s expectations
that the Seaton Landowner Group (SLG) will
adhere to the requirements and
recommendations provided by that study.
The results of the 2012 Duffins Creek
Hydrology Update have been incorporated
into Chapter B, Section B5.1.
REPORT CHAPTER
AND SECTION
Chapter B5.1
The Sernas Group Inc., Stonybrook Consulting Inc. December 2011, Revised February 2013 Master Environmental Servicing Plan - Amendment
SPL Beatty, Bird and Hale Limited, Earthfx Inc. 07161 Seaton Community, City of Pickering
AMEC Earth & Environmental, R.J. Burnside Appendix A7 – Page 1
Amos Environment + Planning