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Arboretum Waterway Construction Update 7.26.17

First weir constructed
The first of five weirs in this section is complete. The basins on either side of the spillway will become containers for wetland plantings.

By Nina Suzuki, Waterway Steward

Full structure of weir
You can see the full structure now.
Diagram of weir
Most of the weir and walls will be hidden by water and wetland plants.

Weir one done!

The first weir has been built. In our 7.7.17 construction update you saw the footings of the weir. Now it has walls, a spillway, and wetland retaining walls on the upstream and downstream sides of the weir. This series of weirs, along with the pump and underground pipe that will move water along the length of the project, are the structures that will transform the Arboretum Waterway from a flat pond to a flowing waterway. This is the first of five weirs in this section. Each weir acts like a low dam with a spillway in the middle that controls the water level at that point. Starting at the east end moving toward the west, each weir will be slightly lower in elevation, so that water flows downstream toward the west end. The wetland plantings upstream and downstream of each weir provide the important function of narrowing the channel and focusing the water flow over the spillway. (See graphic for more details.)

Pump and Pipes

Remember the pump station we showed you in our 6.16.17 construction update?  Now it’s in the ground. The landscaping will be replaced around the pump and you won’t really even notice it’s there once it is fully installed.

Lastly, the contractors are nearly finished installing the underground pipe that will carry water from the pump near Spafford Lake to the east end. Right now you can see the blue 6” pipe in the center of the channel from the pedestrian bridge near Wyatt Deck.

Ground pump
The pump is now installed in the ground near Spafford Lake.
Underground pipe installation
Underground pipe installation is almost complete.


Underground pipe installation
Underground pipe installation near Wyatt Deck.