Skip to Content

Lopez Lake expected to spill excess water into Arroyo Grande Creek during forecasted storms

County of San Luis Obispo Office of Emergency Services

ARROYO GRANDE, Calif. – After adjusted rainfall predictions were issued by the National Weather Service, the County of San Luis Obispo's Office of Emergency Services expects Lopez Lake to spill earlier than previously stated.

Lopez Lake was constructed in 1969 as a water supply reservoir for drinking water and because of that, it has smaller-diameter pipes compared to a flood-control site.

Those skinny pipes mean the county can not release water as quickly in anticipation of incoming rain.

Storms during this year have raised the lake's water levels to near maximum capacity.

As rain begins to fall and the water levels rise, water will fall over the reservoir edge and into the spillway as designed.

The spillway leads excess water into Arroyo Grande Creek and that is where county officials indicate the excess water will have a notable impact on flood risk and debris flow as it has in January and February of this year.

County officials explain that Tally Ho Creek, itself subject to previous flooding this year, is not part of the main stem of Arroyo Grande Creek and is not expected to be affected by the spillway.

To prepare, the county's Public Works office will have road crews staged at areas upstream of Arroyo Grande to free culverts and bridges of obstruction and limit flooding.

Lopez Lake provides drinking water to residents of Arroyo Grande, Grover beach, Pismo Beach, Oceano, and Avila Beach and has spilled a total of 18 times since its construction in 1969. The last spill was in 1998.

Article Topic Follows: San Luis Obispo County
Arroyo Grande Creek
City of Arroyo Grande
flood and debris flow risk
Lopez Lake
Lopez Lake spillway
rainstorm impact
san luis obispo county
storm preparation

Jump to comments ↓

Author Profile Photo

Andrew Gillies

Andrew is a Digital Content Producer and Assignment Desk Assistant for News Channel 3-12. For more about Andrew, click here.


News Channel 3-12 is committed to providing a forum for civil and constructive conversation.

Please keep your comments respectful and relevant. You can review our Community Guidelines by clicking here

If you would like to share a story idea, please submit it here.

Skip to content