Lake Oroville Community Update - June 5, 2020


Aerial view of the Bidwell Bar Bridge.

Aerial view of Bidwell Bar Bridge, Lake Oroville. DWR/2019

Lake Oroville State Recreation Area Resumes Summer Hours

Lake Oroville boat ramp areas are now open along with all Lake Oroville State Recreation Area (LOSRA) facility parking lots and day use areas. While the Oroville Dam Spillway Boat Ramp area is open 5 a.m. to 11 p.m., remaining Lake Oroville boat ramps are open 24 hours a day, seven days a week. Trails and Day Use Areas are open from 8 a.m. to sunset. Lake Oroville recreation information is available on the Department of Water Resources (DWR) Lake Oroville Recreation webpage and the LOSRA webpage.


The Bidwell Canyon and Lake Oroville (Lime Saddle) Marinas are open providing shuttle service, restrooms, and fuel. The Thermalito Diversion Pool and the North Forebay Recreation Area are also open to the public. The Forebay Aquatic Center at the North Forebay facility is now open Friday through Sunday 10 a.m. to 7 p.m. for boat, kayak, and other aquatic equipment rentals. LOSRA campgrounds, including floating campsites, and the Lake Oroville Visitors Center remain closed to protect public health.


California Department of Parks and Recreation (CA Parks) encourages visitors to maintain a physical distance of six feet or more, to keep moving, and to be mindful of congestion on one-way trails. Gatherings, picnics, and parties are not allowed if social distancing cannot be maintained. The Butte County Health Officer recommends face coverings, especially when you cannot maintain a safe 6-foot distance from others. Information on LOSRA facility status can be obtained on the “State Parks Covid-19 Resource Center” website. Information on local health requirements can be found at


Siren Testing at Oroville Dam

Sirens at Oroville Dam will be tested on Tuesday, June 9. This test begins monthly soundings at noon every second Tuesday of the month lasting for three minutes. The 121-decibel level sounding will be audible to neighboring residents, to motorists on Oro Dam Boulevard East, and to visitors of recreation areas around Oroville Dam – including the Diversion Pool, Spillway Boat Ramp area and Oroville Dam Crest Road. The sirens are in place to notify persons near Oroville Dam’s main spillway when water releases are about to begin. Monthly testing allows DWR to confirm the sirens' operational status.


Algal Blooms in Lake Oroville’s North and Middle Forks

Blue-green algae (cyanobacteria) is a natural component of ecosystems. Under certain conditions, including warmer temperatures and increased nutrient loads, algae can grow rapidly causing “blooms.” Algal blooms sometimes produce toxins that can be harmful to people and animals.


DWR environmental scientists regularly monitor Lake Oroville, the Thermalito North Forebay, and the Thermalito Afterbay for blue-green algae and their toxins. Algal blooms have been found in the upper reaches of Lake Oroville’s North and Middle Forks. Recent water samples sent for analysis tested negative.


There are currently no Harmful Algal Bloom advisories for Lake Oroville, the Thermalito Forebay, or the Thermalito Afterbay. If elevated levels of cyanobacteria toxins are found, DWR staff work with California’s Regional Water Quality Control Board and recreation area managers to notify the public and post advisory signs at affected waterbodies. To learn more about harmful algal blooms (HABs), visit the Water Board’s website.


Online Water Education Program Goes Live on DWR YouTube Channel

Join us for Water Wednesdays at 1 p.m. on DWR’s YouTube channel. These family-friendly programs are designed for kids 10 to 14 but are appropriate for anyone who would like to learn more about California’s water resources. The first five topics feature Delta wildlife including fish, plankton, birds, reptiles, and invasive species. Interested participants can pre-register through Zoom which will allow posting of questions to that week’s speaker.


Visit the DWR Events webpage at to join next Wednesday’s chat. Information will also be posted on DWR’s social media pages at @CA_DWR (Twitter) and @CADWR (Facebook). Previous episodes of Water Wednesdays are available on DWR’s YouTube channel.


Current Lake Operations

The elevation of Oroville’s reservoir is about 817.9 feet and storage is about 2.40 million acre-feet. Daily average inflows to the lake have ranged between 2,312 cfs (cubic feet per second) to 2,814 cfs over the past week. 

Temperatures are forecasted to cool this weekend with a chance of rain in the Feather River Basin. During the week of June 8, temperatures are expected to warm with dry conditions. The Northern Sierra Basin rainfall totals remains below average for the year, at 63 percent of normal, and snowpack is significantly below average, measuring 5 percent of normal for this time of year.

On Monday June 1, the total releases to Feather River were increased from 2,500 cfs to 3,000 cfs to meet downstream Bay-Delta water quality and flow standards. In addition, on June 2, DWR increased flow through the City of Oroville to 950 cfs for fisheries purposes. Flows from the Thermalito Afterbay Outlet (Outlet) are about 2,050 to achieve 3,000 cfs for the Feather River’s high flow channel downstream of the Outlet.

All data as of midnight 6/4/20