Trillium Valley Park Pond 48

The detailed design for the retrofit of Pond 48 and re-alignment of Clair Creek is complete and the City is in the process of hiring a contractor for construction. This update will provide information on the final design and what to expect during construction.

Why did it take so long?

The project was started as an Environmental Assessment in 2019, prior to the start of the pandemic. During the early days of the pandemic, the process was slowed as the City’s cash flow was affected by the deferral of tax collection that was implemented. In subsequent years, the city became aware of some major deficiencies at other stormwater management ponds that were causing private property damage. Maintenance of those ponds was prioritized over Pond 48. With those issues behind us, Pond 48 was able to move forward.

Why does Pond 48 need to be retrofitted and the Creek re-aligned?

The details are provided in the Class Environmental Assessment (“EA”) project file report, which can be downloaded from the Documents section of this page. A brief summary is provided below:

1. Pond 48 is what’s referred to as an online stormwater management pond. This means that the pond is attached to a stream, in this case Clair Creek.
2. Online ponds are generally undesirable as:
   1. Online ponds can warm up the water in the creek, making it harmful to fish.
   2. Fish are exposed to the urban pollutants that the pond is supposed to capture
   3. Online ponds are more expensive to clean due to increased permitting, pumping, and erosion control costs.
   4. Cleaning an online pond is a significant and undesirable intrusion into Clair Creek.
   5. Online ponds tend to fill with sediment more quickly, requiring frequent cleanout. The pond was constructed in 1989-1990. Based on aerial imagery of the pond, the pond had disappeared by 1997, suggesting a cleanout frequency of less than 7 years.
3. The environmental assessment looked at options to take Pond 48 offline. The preferred solution requires Clair Creek to be re-routed around a newly constructed, offline, Pond 48.

By retrofitting the pond to be offline and re-aligning Clair Creek around the new pond, it will:

• Function better at removing pollutants from urban stormwater runoff.
• Reduce the frequency of cleanout to a level less more acceptable to adjacent residents.
• Reduce environmental damage by not doing construction within Clair Creek.
• Reduce operating costs by reducing planning, permitting and construction costs as well as lower cleanout frequency.

What is a Class Environmental Assessment?

A Class EA is a provincially regulated decision-making process to ensure good planning when a municipality identified opportunities for improvement on infrastructure projects. The process involves identifying a deficiency/opportunity, creating multiple possible design alternatives to address said deficiency, ranking each alternative against social/environmental/economic considerations, presenting the preferred alternative to the public for review, and filing the final report for 30-day public review.

A public information centre meeting was held at the at the John M. Harper branch of Waterloo Public Library on May 8, 2019. Comments provided indicated agreement with Alternative #5 as the preferred alternative. The project report was filed in September 2022, with the 30 day public review period ending October 8, 2022.

Design Details

The design drawings for the reconfigured pond and creek can be downloaded from the Documents Library. The proposed, off-line Pond 48 will be moved slightly to the northwest from it’s former location. It will be enlarged to improve pollutant removal efficiency to a level closer to modern standards. Due to space constraints, the pond can’t be enlarged to the degree required to fully meet modern standards, so an Oil-Grit Separator unit will be installed in Gatestone Boulevard to assist in removing pollutants. Clair Creek will be re-aligned to the west of the new pond. This design will require that the artificial pond to the west of Pond 48 will need to be removed.

Timing

Permits for the project have been obtained from the Department of Fisheries and Oceans as well as the Grand River Conservation Authority. The project is currently out for tender. Once a contractor is procured, an official schedule with start date will be determined with the contractor. It’s estimated that work will begin late August or early September.

Fish and Herpetofauna Handling and Relocation

Fish rescues and relocation of herpetofauna (i.e. reptiles and amphibians) will be completed by personnel holding valid fish and wildlife handling permits from the Ministry of Natural Resources and Forestry (“MNRF”), and in accordance with MNRF Best Management Practices.

Tree Removal and Restoration Planting Plan

The reconfiguration of Pond 48 and Clair Creek will require significant tree removal to enlarge the pond and re-align the creek. Approximately 59 trees are to be removed. Based on the tree survey completed during the EA, nearly half the trees slated for removal are either:

1. non-native or invasive (i.e. Manitoba Maple, Norway Maple, Norway Spruce);
2. dead Ash trees killed by Emerald Ash borer; and/or
3. in poor condition.

At the request of the Manager of Forestry, the City will be installing armour stone retaining walls to preserve three large trees:

1. Tree ID 156, Norway Maple. Preserved for it’s size/canopy
2. Tree ID 174, Cottonwood. Preserved for it’s size/canopy and rarity in Ontario
3. Tree ID 180, Yellow Birch. Preserved for it’s size/canopy.

The armour stone walls will by virtue of their nature preserve additional trees nearby.

A planting plan has been prepared to restore trees and shrubs following construction, which will include over 80 new trees and hundreds and new shrubs. New trees will be native species such as Tamarack, Basswood, Trembling Aspen, Red Maple, Serviceberry, etc. Shrubs will be native species such as redosier dogwood, ninebark, staghorn sumac, elderberry, etc.

Although the initial tree removal and subsequent construction may seem irreparable at first, please note the photos below that show the nearby Chancery Lane pond during and following construction. The photos show how quickly the pond can regain a more natural and aesthetically pleasing appearance:

Photo 1: Chancery Lane pond during construction in Winter 2021.

Photo 2: Chancery Lane pond shortly after landscape restoration in June 2021.

Photo 3: Chancery Lane pond 1 year after landscape restoration in June 2022.

Photo 4: Chancery Lane pond 3 years after landscape restoration in July 2024.

The 30-day public review period for the study ended on October 8, 2022. The documents remain available for viewing, but the official commenting period for the Project File Report is finished. The city and our engineering consultant will review any comments received and begin the detailed design and approvals process.

The city is pleased to announce that it has completed a retrofit assessment of Trillium Valley Park Pond 48. The project has been completed in accordance with the Municipal Engineers Association Municipal Class Environmental Assessment document (October 2000, as amended in 2007 and 2011), which is an approved process under the Ontario Environmental Assessment Act. Pond 48 has been completed as a Schedule ‘B’ project, which involves a greater degree of study and public consultation, including the completed PIC to present the project to the public and seek input on the identified preferred solution.

A Project File Report has been prepared, which documents; the planning and design process, how public, regulatory agency input was addressed, the evaluation and selection of the preferred solution, along with associated mitigation measures to address impacts, and next steps towards project implementation.

The filing of this report completes the planning and conceptual design stage of the project. By way of this notice, the report is placed on record for a 30-day public review period starting on September 8, 2022 and ending on October 8, 2022.