Here's how wildfires could affect the water in Lake Oroville

The North Complex Fire has burned a large portion of Lake Oroville's watershed. This could lead to hazardous water quality after winter rains run all of that sediment into the lake and the effects could last decades. However, how water quality could be affected by the fire is still largely unknown.

Posted: Oct 12, 2020 6:21 PM
Updated: Oct 13, 2020 8:50 AM

CHICO, Calif. - The North Complex Fire has burned a large portion of Lake Oroville's watershed. This could lead to hazardous water quality after winter rains run all of that sediment into the lake and the effects could last decades. However, how water quality could be affected by the fire is still largely unknown.

The North Complex Fire which burned in both Butte & Plumas counties destroyed many structures and vast swaths of forest. All of that ash & debris will likely run off into the rivers and into Lake Oroville. The main tributaries into Lake Oroville are the North, Middle and South Forks of the Feather River and the West Branch. 

When the rain comes, a lot of what burned will run into these tributaries and deposit all of the sediment into Lake Oroville. The main focus before the rain comes will be erosion control and preventing as much sediment as possible from entering the lake. 

A lot of what burned is organic matter and when it gets deposited into the lake, it will mean a large influx of nutrients. 

"The nutrients are becoming more mobile because they've been burned and they are oxidized. As a result of this increased export in the water, nutrients are peaking in water and that becomes food for algae. And so, following a fire we will see an increase nitrogen export and an increase in algal blooms," said Associate Prof. Sandrine Matiasek, Environmental Sciences, Chico State.

If toxic, algal blooms could harm anyone directly exposed to it and harm the health of the environment and aquatic life.

Recreational use at Lake Oroville should be fine before rain arrives, but that could change this winter.

"As far as direct human impacts on swimming, I would say probably limited. As far as eating fish from Lake Oroville... unsure. It probably will take time for these toxic compounds to build up in fish tissue," said Matiasek.

Farmers & ranchers could also be impacted by water that is toxic.

Lake Oroville is also a part of the State Water Project which supplies drinking water to 25 million people in Southern California. The impacts could be wide-ranging if it becomes unsafe to drink. 

Unfortunately, the impacts wildfires can have on water quality is still quite unknown and will require much more research. 

A FULL INTERVIEW with Associate Prof. Sandrine Matiasek, Environmental Sciences, Chico State is also attached to this article. 

It is about 13 minutes and she describes how wildfires can impact the watershed. 

California Coronavirus Cases

Data is updated nightly.

Cases: 1145209

Reported Deaths: 18862
CountyCasesDeaths
Los Angeles3741347497
San Bernardino875421129
Riverside821751417
San Diego74361984
Orange719531556
Kern39437445
Fresno36688477
Sacramento34186550
Santa Clara31603467
Alameda27857499
San Joaquin24804504
Contra Costa22747258
Stanislaus20932420
Tulare19882304
Ventura18480175
Imperial15568355
San Francisco14662158
Monterey14265115
San Mateo13561170
Sonoma11608155
Merced11388179
Santa Barbara10944133
Kings1025987
Solano974581
Marin7596129
Placer614868
Madera593883
San Luis Obispo581135
Shasta447043
Yolo436374
Santa Cruz400328
Butte376559
Sutter294814
Napa281117
El Dorado20184
Yuba186610
San Benito176716
Lassen17153
Tehama152623
Mendocino144122
Nevada11319
Glenn8537
Lake84519
Tuolumne8068
Humboldt8019
Colusa6636
Siskiyou5652
Mono5073
Amador45716
Calaveras43421
Del Norte2961
Inyo28016
Plumas1810
Trinity1240
Mariposa1202
Modoc1180
Alpine420
Sierra190
Unassigned00
Chico
Clear
43° wxIcon
Hi: 62° Lo: 38°
Feels Like: 39°
Oroville
Clear
46° wxIcon
Hi: 62° Lo: 40°
Feels Like: 42°
Paradise
Clear
43° wxIcon
Hi: 55° Lo: 38°
Feels Like: 39°
Chester
Scattered Clouds
23° wxIcon
Hi: 47° Lo: 25°
Feels Like: 23°
Red Bluff
Clear
47° wxIcon
Hi: 62° Lo: 44°
Feels Like: 43°
Willows
Clear
43° wxIcon
Hi: 64° Lo: 44°
Feels Like: 39°
A cold front has moved over northern California on this day before Thanksgiving, and it brought light rain and snow showers to the higher terrain, gusty wind and cooler air for all. Thanksgiving will still be breezy, but also mild and pleasant.
KHSL Severe
KHSL Radar
KHSL Temperatures

Community Events