Rathburn-Ponytrail Integrated Road Project: Department Responses

1.         Traffic signals at Rockwood Rd. and Rathburn Rd.

Action Plan:  Staff in Traffic Signals to further review all intersection lights and test both Rockwood Road and Rathburn Road left turning signals. 

Traffic Signals staff response:  As a further update, on March 28th, the city’s maintenance contractor was dispatched to the intersection of Rathburn Road @ Rockwood, to check the vehicle detection equipment, timings and pedestrian push buttons. After observing several signal cycles, the maintenance contractor confirmed that the intersection was working properly. 

2.         MiWay Stop at Rathburn Rd. and Ponytrail Dr.

Action Plan:  MiWay staff, in collaboration with Traffic Operations, to review the rationale for the location of the bus stop and traffic flow in the area.

MiWay staff response in collaboration with Traffic Operations staff:  MiWay’s Infrastructure Planning team are in receipt of the concerns raised by residents regarding the relocation of the transit stop at the Rathburn Road East and Ponytrail Drive intersection (Stop #1535).

As part of the Integrated Road Project, existing MiWay infrastructure along the impacted corridor were reviewed and transit stop improvements were identified. Recommendations for such improvements were based on bus stop guidelines and standards, as well as taking into consideration other such factors as ridership, key destinations, and safety of customers and transit operators.

Previously, stop #1535 was located Rathburn Road E, 90m east of Capilano Crt in a midblock position and along a curved segment of Rathburn Rd. As part of the Integrated Road Project, the opportunity arose to improve the stop location by relocating the stop 100m to the east. The relocation was completed for the following reasons:

• The new location was moved to the nearest controlled pedestrian crossing, as a new set of traffic signals were constructed as part of the project. This improves customer safety by facilitating safe pedestrian crossings at signalized intersections.

• The new location is along a straight portion of Rathburn Rd, allowing buses to stop parallel to the curb. This will provide safety for customers as they board and alight the bus by reducing the gap between the bus and the boulevard.

• It was determined that the stop is to be located west of the Rathburn Road E and Ponytrail drive intersection to maintain similar transit service to customers who were using the stop at the previous location.

MiWay is in receipt of concerns raised regarding traffic disruptions caused by buses servicing the new stop location. These concerns have been forwarded to the City’s Traffic Operations team for their review. From Traffic Operations perspective, all bus stops may disrupt traffic flow leading to temporary bottlenecks and delays for other vehicles especially during peak hours. Traffic Operations conducted site observations during peak periods to determine whether this bus stop location is a major contributor to traffic congestions. Between 3:30 p.m. and 5:30 p.m., 5 buses stopped at the location and the recorded times buses spent at the stop were between 12 and 41 seconds.  Neither the frequency of stops nor dwell times at the bus stop was observed having impacts on traffic flow.  Based on these observations, the bus stop location does not cause nor contribute to traffic congestions.

3.         Truck Access (driveway at the Longo’s plaza):

Action Plan:  Capital Works to obtain confirmation with the property management company at Kingsbury Plaza whether an exception has been made for heavy trucks to use the driveway and whether accommodations need to be made.

Capital Works staff response:   Capital Works staff discussed the matter with the Kingsbury Plaza property management company.  The city contractor, Pacific Paving, will be modifying the driveway to accommodate large trucks exiting the Longos, provided that turn restrictions within the municipal right-of-way are obeyed.  The property management company is aware and satisfied with this plan of action.  

4.         Restoration Plantings:

Action Plan:  Forestry staff to confirm the number and type of trees that will be planted within the project area.

Forestry staff response:  Staff will soon be marking tree planting locations along Rathburn Rd/Ponytrail Drive as we near the commencement of the tree planting season. Last year in the Fall, staff did a preliminary walkthrough of the site and noted approximately 135 trees to be planted.  There will be a variety of tree species planted to enhance diversity. Among the variety of species, the faster growing types may include: Northern Catalpa, Kentucky Coffee Tree (both Espresso and Skinny Latte cultivars), Elm (both Patriot and Valley Forge cultivars), Shademaster Honey Locust, Swamp White Oak and Hardy Rubber Tree. Once staff have completed marking Rathburn Rd/Ponytrail Drive, I will provide an update confirming the total quantity of trees and species selected. Please know the 135 trees is an approximate count. This total can change depending on utility conflicts or other site obstructions that may have not been visible at the time of the walkthrough.  

5.         Garbage truck movement within the project area:  

Action Plan:  Capital Works staff to follow up with the Region of Peel on any concerns with the waste collection services in the project area.

Capital Works response:  Capital Works has confirmed with the Region of Peel waste management department that there are no issues with garbage trucks driving within the project area. Capital Works has sent a follow up email and asked the Region to inform us of any future concerns brought up by waste management staff.

6.           Traffic flow on Tapestry Trail:

Action Plan:   Traffic Operations staff to review illegal left turns onto Tapestry Trail.

Traffic Operations staff response:  In response to a concern regarding “No Left Turn” violations at the intersection of Rathburn Road East and Tapestry Trail, the Transportation and Works Department provides the following information.

Observations during the morning and afternoon peak periods were completed by staff to determine the level of compliance.  The results revealed no left turn violations in the morning and only three (3) recorded in the afternoon.

Staff also completed the evaluation of existing signage and pavement markings to ensure proper visibility, free of any obstructions, properly displayed and in good condition and found these to be adequate.

Furthermore, a review of the collision history at the subject intersection did not reveal any reported collisions within the past five years. 

Staff realize that instances of sporadic violations of turn prohibition do occur and encourage all City of Mississauga residents to file an online driving complaint report of such behaviors via the Peel Regional Police internet website www.peelpolice.ca using this link https://bit.ly/31NghiE.  This will enhance their response service and time to all complaints in our region.  Peel Regional Police are hoping that this will also foster a stronger relationship with community members.

 7.         Bioswales:  

Action Plan:   Stormwater Assets staff to provide more information regarding the bioswales including a rationale for their size and function, as well as the City Inspection/Maintenance Program.

Stormwater Assets and Programming staff response:

Stormwater Design Criteria

The City of Mississauga Development Manual outlines the stormwater management (SWM) criteria and storm sewer design requirements. The Toronto and Region Conservation Authority (TRCA) document (August 2012) also includes SWM criteria that developments must adhere to within the TRCA regulated areas. This site is within the Etobicoke Creek sub-watershed area, which has specific design criteria further described below.

Water Quantity Control Requirements

Post development peak runoff flows are required to be controlled to pre-development conditions for all design storms events (i.e. 2-year to 100-year storm events).  This ensures that new developments do not increase the risk of flooding.

Water Quality Control Requirements

This stormwater management criterion stipulates that all watercourses and waterbodies within TRCA’s jurisdiction are classified as requiring an “Enhanced” level of protection (Level 1). Level 1 water quality protection requires the removal of 80% Total Suspended Solids (TSS) from stormwater before discharging to a watercourse. To minimize thermal impacts, preventative measures (e.g. LID practices such as bioretention cells) and mitigation measures should be implemented.

Runoff Volume Reduction

Stormwater runoff from developed sites impacts streams and watercourses by introducing erosive forces during frequent storms.  The first 5 mm of runoff is required to be retained on-site and managed by way of infiltration, evapotranspiration, or re-use.

Implementation

Stormwater quantity control, quality control, and runoff volume reduction are required to control the increase in stormwater runoff from a development site.

The impervious (paved) area for a portion of the Rathburn-Ponytrail Integrated Roads Project has been increased to facilitate roadway and active transportation improvements. Therefore, stormwater infrastructure is required to provide quality control, quantity control and runoff volume reduction.

The Rathburn Road East drainage system has been configured with a series of LID Bioswales, specified in accordance with the TRCA / CVC Low Impact Development SWM Planning and Design Guidelines to provide 80% TSS removal.  The materials and dimensions (length, width, and depth) of the Bioswales were designed to treat the volume of stormwater runoff generated from the site, to meet the design criteria.

In Summary

• Regulatory authorities require that post development peak flows match pre-development peak flows (so that there is no increase in stormwater runoff);

• Stormwater quantity and quality controls were required for the project;

• The LID Bioswales were designed for this project to meet the minimum requirements;

• LID Bioswales are an accepted best management practice to provide the required stormwater controls;

• Surface access to the LID Bioswales permits City staff and contractors to inspect, test and maintain the infrastructure.

Inspection and Maintenance:

The City will take responsibility for the ongoing inspection and maintenance of these LID bioswales.  Stormwater LIDs are inspected annually (at a minimum) by City Stormwater staff to document their condition and identify any deficiencies. The City Forestry group also assists with removing weeds, trash/ debris removal and re-seeding/ re-planting.  If other deficiencies are identified during the inspections, these can generally be addressed by the City’s Works Operations and Maintenance groups.

Additional information on the Bioswales:

Background/ Evolution of Stormwater Management Criteria:

Traditional stormwater management (SWM) in Ontario for pre-1990’s development used catchbasins and underground pipes to collect stormwater from paved areas and discharge it directly to nearby watercourses or waterbodies.  These designs function well for draining hard surfaces, such as roadways and parking lots. However, they also created several problems, including:

• Risk of downstream flooding - as stormwater runs off paved surfaces more quickly and is discharged into creeks and rivers;

• Watercourse erosion - as the increased flows can damage existing channel beds and banks;

• Pollution in waterbodies - as flowing stormwater collects oils and debris from roadways and discharges it directly into watercourses, which drain to Lake Ontario;

• Reduced groundwater recharge - as stormwater that falls on paved surfaces is unable to infiltrate into the soil;

In the 1990’s/2000’s, the Ontario Ministry of the Environment (MOE/ MECP) published design guidance to address the problems described above.  In addition, Conservation Authorities developed various flood control criteria.  Municipalities are required to uphold these various legislated criteria for regulating new development and when designing municipal projects.

Stormwater management ponds are frequently used for new residential developments to capture stormwater runoff, provide flood control and reduce pollution before discharging to a local watercourse or waterbody.  However, for road retrofit projects or re-developments with space constraints, it is often not feasible to construct large stormwater ponds to meet modern SWM design criteria.

In recent years, Low Impact Development (LID) infrastructure has become common as a best management practice in Ontario, to meet the required SWM design criteria.  These are often installed within the road right-of-way.  Engineered Bioswales are a type of this LID infrastructure and are designed and sized to capture specific runoff volumes from the development or retrofit area.  Bioswales can help control stormwater runoff for quantity (flood) control, provide water quality (pollution) control, runoff volume reduction (to mitigate creek erosion) and promote groundwater infiltration.

Bioswale Sizing for Rathburn Road:

When the City designs a roadway, such as an Integrated Roads Project, the condition and capacity of the stormwater system is evaluated.  This section of Rathburn Road was constructed in the 1970’s, prior to modern stormwater controls, and so the project is required to comply with modern SWM design criteria. The consulting engineer for the Rathburn-Ponytrail Integrated Roads project designed the LID Bioswales to manage stormwater runoff for the project - primarily the road surface and other paved areas - and comply with SWM design criteria.

Bioswale Plantings:

The current Bioswale design is to be left unvegetated in the middle with mulch/woodchips.  It is possible to incorporate plantings into the existing Bioswale that can survive the drought/salt conditions expected at the roadside.  Planting grass-sod is also an option.  At this time, adding new plantings or sod to the Bioswales will impact the contractor’s two-year warranty and so City staff recommend leaving the Bioswales unvegetated (i.e. mulch/ woodchips).  However, after the warranty period is complete and the Bioswales have been fully assumed by the City, appropriate plantings can be further considered.  Whether the plantings can be flowering/ colourful will depend on the appropriate species for the site conditions.