Monday, 9 November 2015

Haggart Isl. Dam and Bridge repair on the Tay River

View from Thom St.
Haggart Island, I didn't even know it was there! They call it the Rainbow Bridge, although there are two! I was curious.

...starting October 22nd, 2015, the Town of Perth, in cooperation with local construction industry, will be working with the Rideau Valley Conservation Authority (RVCA) in the removal of the small Haggart Dam on the Tay River.   It is expected that the Rocky Ramp project will be completed by mid-November, 2015. 

Quite complicated, since there are fish in the river, and the river floods Stewart Park. It's a river that needs some work, as well as the old structures. There were problems, since the water level has dropped 30cm, and while people could swim in one arm of the river, there were flooding and erosion issues. There is some danger from fixtures needing repair, as well as the deteriorating old mill. This is part of Perth town proper, and has existed since its founding in 1816., albeit it's original construction has changed since it has been repaired.

It's a complicated project, politically, since there are many stakeholders: the town of Perth, nearby landowners, the RVCA,  Friends of the Tay, as well as dam construction codes.

The applicable design codes relating to the evaluation of the dams are:
  •  Canadian Dam Safety Association  Dam Safety Guidelines 
  •  Canadian Foundation Engineering Manual 
  •  CAN/CSA–A23.3 Design of Concrete Structures 
The pedestrian bridge over the Tay Road Dam would be subject to:
  •  CAN/CSA-S6-00 Canadian Bridge Design Code

Haggart Island
"The island can be accessed via the Mill Street Bridge, east of the island, from the Rainbow Bridge on the west side, from a second Rainbow Bridge on the north side and from a pedestrian bridge located next to the weir on the northeast side of the island. ...there is an informal pathway between these access points that is used by locals throughout the year but less so by tourists due to the lack of signage and public information. "

The Tay is used by both small watercraft and skaters, according to the season.  There are lots of fish species, as well as other aquatic critters.
RVCA did a large 54-page study (see the link below).
Finally, the subject area should be further developed as naturally oriented as possible for both terrestrial and aquatic environments. In this regard, it is suggested that:

  •  Enhance fish habitat area. 
  •  Enhance the natural aspect of the riverbanks by pruning the existing trees and shrubs as required as well as removing non-native plant material. 
  •  Promote bank stabilization through natural methods (vegetation). 
  •  Develop controlled flows down the Little Tay to reduce bank erosion.

RVCA staff electrofishing along the Tay River to relocate fish away from construction zone at Haggart Island Dam. They relocated the fish, prior to the work.


[PDF]Haggart Island Dams - Rideau Valley Conservation Authority


EG CameraGirl said...

Yep, sounds very complicated! Hope all turns out well!

William Kendall said...

It does sound like it's complicated!