As 2021 enters peak fire season, firefighters across the state are battling over a dozen blazes. This year, record breaking temperatures paired with unusually dry conditions have set California up for a devastating fire season that could surpass last year’s already unprecedented wildfires. So far, Cal Fire reports roughly 2 million acres burned and over 3,000 homes, businesses, and other structures damaged or destroyed in the 2021 fire season. The Dixie fire, which has burned for two months and scorched over 900,000 acres of Northern California, is now the second largest fire in state history--right behind the August Complex of 2020.

Even as heroic firefighters work to contain the blazes, state officials warn that ongoing drought conditions could extend this year’s fire season. California entered 2021 bone-dry after an exceptionally mild winter and overall the entire state is experiencing moderate drought conditions, according to the US Drought Monitor. 45% of California is experiencing D4 or “exceptional” drought conditions, the most severe classification. Winter isn’t likely to bring much relief either. Recent federal climate forecasts are predicting another La Nina weather event, which means a warm, dry winter for much of California. Amid these increasingly dry and hot conditions, Californians can expect the fire season to last until the end of the year. “This season is far from over,” warned Cal Fire Chief Thom Porter in a recent CNN article. “We are on par with where we were last year. That’s sobering and that is the new reality.” 

The cost of this new reality is high. In addition to the billions of dollars poured into emergency fire suppression, millions more go towards cleaning up and rebuilding damaged communities and environments. But in the aftermath of gargantuan fires like the August Complex and Dixie fires, there is a subtle yet salient issue that often goes overlooked:  water quality impacts. 

For any community caught in the smoke and ash of a smoldering wildfire, the fallout can be just as bad as the initial disaster. According to the United States Geological Survey (USGS), “wildfires can compromise water quality both during active burning and for months and years after the fire has been contained.” While the fire is raging, it spews ash and fine particles that then settle on the surfaces of lakes and reservoirs used for drinking water supplies. These contaminants introduce hazardous chemicals into the water that pose a danger to water quality and a challenge for water treatment. Active fires also tend to disrupt electric grids that power water quality monitoring systems, forcing suppliers to switch to secondary water sources. These secondary sources usually provide lower-quality water that may require additional, expensive treatments for potable use.

Even after the fire is put out, the burn scars left behind are highly susceptible to erosion and can wash large amounts of contaminated sediment into streams, rivers, and reservoirs. Without vegetation to keep the soil in place, storms can cause dangerous flash floods that could potentially overwhelm or damage stormwater and reservoir infrastructure. 

The impacts that wildfires can have on water quality are especially devastating when fires burn in the Sierra Nevada mountains. The Sierras provide 60% of California’s water and yield higher-quality water than many other sources. Sierra forests also tend to serve as fuel for wildfires, which puts a significant portion of the state’s water supplies at risk. This year, the Dixie fire made state history as the first wildfire to burn across the entire Sierra mountain range. The toxic by-products of the Dixie fire will likely impact water sourced from the Sierras for months; increasing costs associated with water treatment and diminishing reservoir capacities. 

The timing could not be worse. The ongoing drought has heralded a patchwork of water shortages and surpluses across California. While some water providers, such as Metropolitan Water District, are at higher storage capacity than ever, many smaller providers in cities like Palmdale and Mendocino are struggling to meet demand. Several state reservoirs are at all-time lows. Even the seemingly endless Colorado River, which supplies California with 4.4 million acre-feet of water annually, declared a historic water shortage over the summer. With California facing an ongoing water crisis, maintaining the quality of the water left available is critical. 

Over the coming months, municipal water supplies and downstream aquatic ecosystems will face a variety of challenges from the ongoing wildfires. The USGS reports that the potential short- and long-term effects include:

• Changes in the magnitude and timing of snowmelt runoff, which influence filling of water-supply reservoirs.

• Increased sediment loading of water-supply reservoirs, shortened reservoir lifetime, and increased maintenance costs.

• Increased loading of streams with nutrients, dissolved organic carbon, major ions, and metals.

• Post-fire erosion and transport of sediment and debris to downstream water-treatment plants, water-supply reservoirs, and aquatic ecosystems.

• Increased turbidity and heightened iron and manganese concentrations. This may increase chemical treatment requirements and produce larger volumes of sludge, both of which would raise operating costs.

• Changes in source-water chemistry that can alter drinking-water treatment.

All told, wildfires--past, present, and future--pose a significant danger to the quantity and quality of affected water systems. 

So what can we do?

As a water community, we need to dedicate more resources to understand the short- and long-term effects of wildfires on water quality, as well as the recovery process and possible preventive measures. The dismal truth is that wildfires, especially massive “giga” fires that burn millions of acres, are not going away. Experts predict that, due to climate change, forest wildfires in Northern California, as well as Oregon and Washington, could increase 78% in area burned by 2050. On the bright side, California’s lawmakers are already taking some preliminary steps. This September, lawmakers allocated 2 billion dollars towards wildfire prevention and drought relief. The AP reports that the money will go to activities like forest maintenance and the strategic clearing of brush and trees. It will also pay for more inspectors to review homes in wildfire prone areas prior to purchase. Lawmakers also approved 1.2 billion to pay for items like grants planning for climate change, water recycling projects, and efforts to clean up contaminated water sources. 

Although the forecast for California’s wildfires and water supplies looks bleak, there is still time to invest in climate change resiliency for both wildfire prevention and water quality protection. The worst thing we can do now is nothing. 

As an environmental testing laboratory, Babcock Laboratories is dedicated to ensuring water quality and protecting public health. We are a NELAP and CA ELAP accredited laboratory that specializes in water quality analyses. Click here to learn more about our testing services.