SPECIAL REPORT: Non-native plant invading Salinas River

An invasion underway at the Salinas River and now there is an effort underway to remove the non-native plant.

The Salinas River has been taken over by what looks like a forest of bamboo. The plant is called Arundo. It has taken over the riverbank and moved inland.

“It is just a tenacious plant. It invades areas where it flows during high flow events,” said Emily Zefferman, ecologist with Salinas River Arundo Control Program.

Removing this invader is now one of the Resource Conservation District of Monterey’s biggest project.

Emily Zefferman is an ecologist with the Salinas River Arundo Control Program.

Zefferman says Arundo was originally planted back in the 40s to protect the river bank and stabilize the levies, but then it started spreading quickly.

The river bed is dry now, but when the river rises the plant can detach and clog the river.

“This is really the Arundo that we care the most about because it has the most potential to mobilize in a flood and reinvade in areas downstream.”

The challenge has been stopping the Arundo.

“You don’t just treat it once. You have to hit it over and over and over, so there is three to four to five treatments,” said Paul Robins, Executive Director, RCDMC.

That costs millions of dollars and one of the biggest problems is the plan is huge, it can get up to 30 feet tall and grow as much as four inches per day.

The team started their eradication season this year in this area in Soledad.

“This area was mowed in fall of 2017, so about a year ago and all of this growth was between about March and July,” said Zefferman.

For a state as dry as California, Arundo also isn’t helping.

“One of the problems with Arundo is it uses a lot more water, and sucks up a lot more water than native vegetation so it contributes to the drought. So in dry years it will suck up water that is scarcely available.”

That kills nearby trees, but it also causes problems problems for fish, wildlife, and creates a fire hazard.

“Especially if you are near an urban area, or a bridge, or a place where possibly a homeless encampment could develop, or other groups of people that might light a fire,” said Paul Robins.

While the eradication program has made great strides there is more work to be done.

“You’re not going to see every blade of plant and there is going to be stuff that regrows, so we see it down to a manageable state and then ideally over a much longer period, potentially eradicate it,” said Robins.

Arundo grows like weed, one that could take another 15 to 20 years to completely remove.