OCEANSIDE — The roar of a massive mower can be heard along the banks of the San Luis Rey River where a crew is at work chopping down woody plants.
Riverbed mowing from College Boulevard to Benet Road is scheduled from now through the end of November to clear plants obstructing the water flow.
If the riverbed is not cleared of plants, water will not flow properly and flooding may occur. The target is to improve water flow to 71,200 cubic feet per second.
“Native willow up to 30, 40 feet and taller are thriving in there and invasive Arundo donax,” said Raina Fulton, project manager for Army Corps of Engineers.
The ACOE is completing the project because of the sensitive nature of endangered species in the area.
The project was stalled for 12 years while its impact on endangered species was studied and a habitat management plan was developed along with flood control efforts.
Project guidelines include yearly assessment, ongoing environment monitoring and adjustments to efforts based on findings.
“It is the Corps’ mission to reduce flood risk and to improve environmental quality,” Fulton said. “That’s why we are here.”
Current mowing is phase two of the four-phase flood prevention project. Efforts also include levee repair, vegetation management, inspection of storm drains, species monitoring and spraying.
ACOE began the first phase of the project in 2008. During phase one the city mowed the riverbed in 2010 and 2011.
An environmental analysis of endangered species was conducted after phase one was completed and needed adjustments to the plan were made.
Future actions will be to start phase three mowing and maintenance next fall.
In the fourth and final phase of the project, sediments will be removed from the river bottom.
The project is expected to be completed in 2019. At that time the city will take over the responsibility to maintain the area.
The total cost of the project is $110 million. Federal funds will pay for 75 percent of the project and city funds will pay for 25 percent of the project.