4 months ago
ROSEVILLE, CA - Its green leaves and bright yellow flowers may look nice at first, but the weed that is rapidly growing in Roseville's Linda Creek might be more destructive than decorative.
Ludwigia, or water primrose as it's commonly known, is an invasive herb that can double in size in only two weeks. In July and August last summer, the weed gradually covered over a mile of Linda Creek. In some places, the weed became a bank-to-bank carpet on the waterway.
"It literally covered from bank to bank and in a couple of spots, as far as the eye could see," said Brian Castelluccio, Roseville's open-space manager. "One hundred, one-hundred-fifty yards solid, the plant was covering the creek. Happened within a two-month span."
Recent rains have actually helped move the weed downstream. Since it is so fragile, faster currents help keep the weed from staying too established.
The city first became aware of the problem when residents in the nearby Meadow Oaks neighborhood became worried the plant would grow big enough to clog the overflow bypass channels, potentially raising flood risk.
Linda Creek is also a salmon habitat. The ludwigia's vines could possibly hinder the salmon's migration. If the weed completly covers the surface of the stream, oxygen and pH levels are compromised.
Jim Williams, who has lived in the neighborhood during some big flood years, says this weed is more of a mystery. "It was something. We went out of town for a couple of weeks and came back and it had doubled its size," he said. "Problem is, next year it might be worse, I don't know."
The city of Santa Rosa has been battling ludwigia for years with little or no success. Their main concern is a rising mosquito population.
What will the city of Roseville do now? Wait and see, say officials.
"It's really dependent on the environment," said Castelluccio. "If the flow is fairly quick (next summer) and the water levels are higher, there's a less likelihood it will survive. If the water levels drop and the temps are warmer, that's the environment it likes and then it will start to grow."
by John Larimore, jlarimore@news10.net
News10/KXTV
