Arboretum Waterway

To provide multiple ecosystem benefits, students on our Learning by Leading Waterway Stewardship team are creating riparian (water edge) habitats around the newly constructed weirs throughout Phase One of the Arboretum Waterway Maintenance and Enhancement Project.

Naturally occurring, iron-oxidizing bacteria can create a film similar to oil (see photos), however it is completely harmless and goes away over time.

The path on the north side of the Arboretum Waterway is open again, now that construction on Phase 1 of the Arboretum Waterway Maintenance and Enhancement Project is nearing completion.

The weirs in Phase One of the Arboretum Waterway Maintenance and Enhancement Project are functioning beautifully. They allow water to flow from the east end of the Arboretum Waterway (where the weirs are located) to the west end of the Arboretum Waterway (near the Equestrian Center) where pumps send the water all the way out to Putah Creek. Once here, the water eventually reaches the San Francisco Bay.

The majority of the Arboretum is still open for walking, jogging, strolling, smelling the flowers and all the other activities you normally enjoy in the Arboretum except the portion between our Australian / New Zealand collection at the east end of the Arboretum up to, but not including, the Redwood Grove.

Open during construction!

As the holiday season approaches and guests start traveling to town, please remember that the Arboretum is open during construction!

We’re still finishing up Phase One of the Arboretum Waterway Maintenance and Enhancement Project, but the construction fencing located in T. Elliot Weier Redwood Grove and Lake Spafford areas is now removed! We expect the pump controller to be programmed by the end of November. Once it is ready, we can turn the pump on and see the water flow over the weirs.  If the weather holds out, you can also expect to see some new plants getting planted around the weirs in December.

The construction dam is down and water is now back in parts of the phase one project area. (Phase one of the Arboretum Waterway Maintenance and Enhancement Project extends from the easternmost portion of the waterway all the way to Wyatt Deck near Lake Spafford.) We're now working with contractors to test and optimize the pump system, which is an essential part of the waterflow in the Arboretum Waterway.

Four out of the five weirs for Phase 1 of the Arboretum Waterway Maintenance and Enhancement Project are complete, and the last weir should be finished by the end of September. This means we are very close to being able to return water to the channel and watch the water flow over the new weirs and through the wetland plantings.

The first weir has been built. 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.