Lopez Lake spilled for the first time in nearly two decades early Thursday morning, thanks to a burst of rain during the latest storm sweeping across California this week.
The man-made reservoir — which acts as a water source for southern San Luis Obispo County as well as a popular recreational destination for boating, fishing, camping and swimming — reached 100% capacity at 4:21 a.m., according to the San Luis Obispo County Public Works Department’s live water monitors.
The lake had spilled 35.2 cubic feet of water per second as of about 8 a.m., the San Luis Obispo County Public Works Department’s live water monitors said.
The water topped over into the lake’s spillway, where it was directed into the Arroyo Grande Creek.
This is the first time in 25 years that the South County lake has spilled. According to officials, the lake last overflowed in 1998.
It was one of the last local reservoirs to reach full capacity after a winter with heavier-than-usual storms filled most all to bursting in recent weeks.
Lopez Lake notably started the year at an almost devastatingly low 24% of capacity on Jan. 1, but successive storms helped to raise the level exponentially in the weeks following.
Ahead of the lake reaching full capacity, officials said they planned to keep a wary eye on potential flooding downstream once Lopez Lake spilled, since the water would go into the already flood-prone Arroyo Grande Creek.
Video from @SLOTribuneLaura shows Lopez Lake spilling over after recent storm. The reservoir was 100% on Thursday. You can read all about it via @SLOTribune at https://t.co/FuTg72OTl1 pic.twitter.com/p1G04GEA9P
— Kaytlyn Leslie (@kaytyleslie) March 23, 2023
On Monday, residents in Oceano were warned of potential evacuations if the creek’s water levels rose drastically once again during the storm.
“We know that for Oceano residents, evacuation fatigue is setting in,” Emergency Services Manager Scott Jalbert said in a county news release. “However, water levels in the channel combined with additional rain and water spilling from the reservoir are creating a potentially dangerous situation.”
Residents were told Wednesday night the evacuation warning would stay in place until the lake spilled and officials could assess the situation.