Report for Transportation and Public Works Committee July 8, 2003 Meeting

23 Avenue (Terwillegar Drive to 119 Street) Concept Planning Study

1. That the 23 Avenue (Terwillegar Drive to 119 Street) Concept Planning Study be approved (Attachment 1 of the May 20, 2003, Transportation and Streets Department report).
2. That the final alignment and location of the Whitemud Creek pedestrian bridge, multi-use trail, and stormwater management pond be determined upon completion of the detailed Environmental Impact Assessment Report.

Report Summary

This report outlines a recommended concept plan and staging strategy for the upgrading of 23 Avenue (119 Street to Terwillegar Drive).

Report

• Riverbend/Terwillegar continues to be one of the most rapidly growing suburban neighbourhoods in Edmonton. Traffic volumes on 23 Avenue have increased from 6,700 veh/day in 1997 to 12,600 in 2002. Single-amily lot servicing is anticipated to continue at an annual rate of 500 to 600 lots per year in the neighbourhoods between the TransAlta right of way and Anthony Henday Drive, and, at the current rate of development, build out of the neighbourhoods in this area is anticipated to occur within ten years.
• In addition to the growth occurring in the area, both through and neighbourhood generated traffic volumes on a number of roadways in the Riverbend/Terwillegar area will be affected by changes in the roadway network, as shown in Attachment 2:

1. Completion of the southwest quadrant of Anthony Henday Drive between Whitemud Drive and Gateway Boulevard by 2006, including the recently announced construction of an interchange at Terwillegar Drive.
2. Extension and widening of Terwillegar Drive to a four lane roadway between Anthony Henday Drive and Rabbit Hill Road, to be completed by 2006.
3. Extension of Terwillegar Drive south to Ellerslie Road, servicing the proposed Windermere residential area.
4. Staged upgrading of Whitemud Drive/Terwillegar Drive, identified in the CPP as commencing in 2007, including the 40 Avenue – Terwillegar interchange and rehabilitation and widening of Quesnell Bridge.

• These network improvements will affect traffic volumes on 23 Avenue, both in accommodation of growth, and accommodation of detour traffic during certain stages of Whitemud Drive/Terwillegar Drive upgrading.
• Attachment 1 is the Executive summary of the 23 Avenue concept planning study and includes the recommended roadway configuration. Key objectives of the concept planning study are:

identify upgrading needs for 23Avenue to rectify existing problems, to accommodate future growth, and manage access;

identify stormwater management requirements for the roadway corridor;

identify methods for accommodating pedestrians and other trail users along the upgraded roadway;

identify the right-of-way required to accommodate the recommended roadway improvements including all related elements such as drainage, utilities, and pedestrian facilities; and

identify an implementation strategy based on the priority of the recommended improvements.

The concept plan considered a number of key issues which need to be addressed as part of this project, including:

• Roadway Capacity: There is a need to provide additional peak direction roadway capacity along 23 Avenue, from 142 Street, across Whitemud Creek to 119 Street.
• Ultimate Configuration of 23 Avenue: The ultimate roadway configuration and alignment of 23 Avenue need to be established and confirmed in light of factors such as geotechnical and environmental requirements.
• Roadway Staging: The sequence of upgrading 23 Avenue from its existing two-lane rural standard to its future configuration must be coordinated with ongoing land development activity in Riverbend and areas further south.
• Whitemud Creek Crossing: There are a number of options available for providing additional roadway capacity across Whitemud Creek. These options include widening the existing bridge, as well as building a separate new bridge.
• Pedestrian and Cyclist Circulation: The current 23 Avenue crossing of Whitemud Creek is extremely narrow and not conducive to pedestrian or bicycle movement. The “Recommended Plan” must address pedestrian and cyclist movements along 23 Avenue and across Whitemud Creek and integrate with the Community Services Department plans to provide recreational trails without the Whitemud Ravine Natural Reserve.
• Geotechnical Issues: The area adjacent to the existing creek crossing has an extensive history of ground movement that will have a bearing on roadway options, bridge options and cost.
• Environmental Issues: Whitemud Creek lies within the area governed by the North Saskatchewan River Valley Bylaw. All roadway and bridge upgrading plans will have to satisfy the bylaw requirements as well as those of the Canadian Environmental Assessment Agency (CEAA).
• Stormwater Management: The addition of traffic lanes along 23 Avenue will increase the amount of stormwater runoff that will need to be captured and discharged. Since direct discharge to Whitemud Creek is not permitted, a stormwater management plan must be developed to demonstrate how stormwater will be handled once 23Avenue is expanded. The stormwater management plan will need to consider and be coordinated with stormwater plans for the developing lands in the Riverbend area.
• Stakeholder involvement process:

A public open house for the project was held on March 20, 2003, at St.Thomas More Church. Limited attendance at the open house was received, so the open house was supplemented by a display at the Riverbend Library from April 1, 2003, through May 8, 2003. Eight follow-up phone calls or requests for information flowed from the library displays, with the majority of calls supportive of the plan but concerned about the urgency of construction given the rate of growth in the area.

• Recommended Plan

Following a review of options, analysis of existing/future traffic conditions, construction costs, and consideration of geotechnical and environmental issues and stakeholder feedback, a “Recommended Plan” has been developed for 23 Avenue. The plan displayed at the March 20, 2003, Open House, and at the Riverbend Public Library will be implemented in two stages. The staged approach to implementation is aimed at upgrading the roadway in a sequence that reflects upgrading areas of greatest need and priority in light of limited funding.

• The following works are recommended at each stage of construction:

Stage 1 Improvements:

In light of extensive subdivision activity north and south of 23Avenue near 142 Street/Rabbit Hill Road, there is an immediate need to upgrade 23 Avenue from Terwillegar to the top of the Whitemud Creek Valley, including the widening of 23 Avenue to four lanes in this area, including substantial improvements to the 23Avenue/142 Street intersection. The existing roadway will be left in place and used for eastbound traffic, while a new set of traffic lanes will be built north of the existing road to accommodate westbound traffic. Staging of construction in the area must also be coordinated with planned construction schedules for Terwillegar Drive.

In addition to the roadway improvements noted above, a new 2.5 m to 3 m wide multi-use trail is to be constructed along the north side of 23 Avenue, from Town Centre Boulevard, eastward across Whitemud Creek (on a new pedestrian bridge) to 119 Street.

Stage 2 Improvements:

Growth will necessitate upgrading of the intersection of 23 Avenue at 119Street, as well as twinning of a short section of 119 Street from 23Avenue to 28 Avenue.

This second stage of improvements will also involve the construction of a new two-lane bridge across Whitemud Creek, immediately north of the existing bridge. The remaining two-lane sections of 23Avenue on both sides of the creek will also be twinned; this will result in a four-lane roadway for the full length of 23Avenue, from Terwillegar Drive to well past 119Street.

To handle the additional stormwater runoff from the new traffic lanes across Whitemud Creek, a storm pond must be constructed. The pond will enable stormwater to be captured and then released into the creek at a safe and controlled rate.

In order to address concerns regarding potential impacts on the ravine area, an Environmental Impact Assessment will be undertaken as part of the design process.

• Cost Estimates and Funding Strategy

The cost of Stage 1 widening of 23Avenue from Town Centre Boulevard to east of 142 Street, plus the development of a multi-use trail connecting 142 Street to 119 Street is estimated to be $7 million. Of this cost, approximately $4.6 million is attributed to the widening of 23Avenue east of Terwillegar Gardens and is directly related to traffic impacts associated with developments in the area. Developers in the Terwillegar area have agreed to fund the required costs of the twinning of 23 Avenue in this area through an increase in the value of the Arterial Roadway Assessment. It is noted that the City will be fully funding the improvements on Terwillegar Drive, in addition to the balance of twinning on 23 Avenue west of Terwillegar Gardens, and the multi-use trail across Whitemud Creek ravine. Of the required $2.4million in City funding, the Capital Priorities Plan currently includes funding for $2million in 2007. Under the proposed debt funding scenario, the completion of the widening and multi-use trail development, including the section west to Terwillegar Drive would be funded and accelerated to ensure completion prior to the completion of major roadway upgrading on Terwillegar Drive.

The cost of Stage 2 widening of 23Avenue across Whitemud Ravine, plus required intersection upgrading at 119 Street north of 23 Avenue is estimated to be $8.6 million. This project is identified to be funded in the second half of the Long Range Financial Plan and will be required to accommodate planned development in the area within the ten-year time period.

Budget/Financial Implications

• The current 2003 to 2007 Capital Priorities Plan includes funding of $2million towards the implementation of Stage 1 improvements. In addition, developers in the area have agreed to an increase in the arterial roadway assessment that will ensure construction of the required widening in the area from west of Whitemud Ravine to the Terwillegar Gardens access west of 142Street.

Justification of Recommendation

1. Approval of this recommendation is required in order to define required property lines in the area and to allow detailed design and construction activities to be undertaken.
2. The River Valley Bylaw 7188 requires a detailed Environmental Impact Assessment prior to completion of the Preliminary Design. This report will address issues related to the multi-use trail alignment and the location of the stormwater management facility.

Background Information Attached

1. 23 Avenue Concept Planning Study, Executive Summary.
2. Planned Network Improvements.

(Page 1 of 5)