How might the drought affect firefighting?
By Katherine Minkiewicz-Martine, Staff Writer, SoCoNews, June 28, 2021
As the ongoing drought intensifies with record low reservoir storage levels, folks may be wondering what would happen if there’s another Sonoma County wildfire. Where would fire crews get their water to use in a fire fight?
Helicopters shouldn’t have a difficult time finding usable water for a fire, however, water tenders may have to drive further to find water sources that are deep enough to pull water from, thus creating a longer turnaround time for tenders to deliver water to a fire line, according to Ben Nicholls, fire chief of the CalFire Sonoma-Lake-Napa Unit.
“With the exceptional drought that we are in, obviously that’s affecting reservoir levels for our major reservoirs and then obviously into the smaller reservoirs throughout the county and the state. That’s definitely going to give us less fill points, less water sources closer to the fire to supply firefighting operations, but so far we have not seen a critical impact to firefighting operations,” Nicholls said.
For instance, with the one-acre fire on Porter Creek Road last week on June 16, crews were able to make water drops with a helicopter.
“(With that) fire right across from Camp Newman out on Porter Creek Road, our helicopter was going to the reservoir about 3.5 air miles from the fire and with our helicopter it actually worked out perfect,” Nicholls said.
The helicopter was able to get water to apply to the fire and while it was off getting water, the mix-wing air tanker was able to work on making retardant drops. The retardant that air tankers and mix-wing aircraft use is mostly water, however, it has a pink hue to it so fire crews can keep tabs on where drops have been made.
Water supply is less of a concern for helicopters because they have the ability to pull from smaller water sources. The helicopter can insert vertically into a creek or reservoir and either fill a bucket with water, or with the newer aircraft, insert a hose that can draw water up into a fixed tank.
Helicopters also have an advantage over water tenders because they can travel over long distances quickly if they have to find an alternative water source.
Very Large Air Tankers, or VLATs, primarily come from large air attack bases and use municipal water sources to fill up.
Both Lake Mendocino and Lake Sonoma are at incredibly low storage levels, however, Nicholls said normally they wouldn’t pull water from those reservoirs unless there was a fire nearby.
“Normally those reservoirs, unless the fire is close to those reservoirs, are not water sources that we are pulling from. That’s the benefit of helicopters, is that we can pull from smaller water sources,” Nicholls said. “We use any body of water that has enough space to get a helicopter into and where the water is safe. From time to time, there’s contaminated water sources in the form of sewer ponds or other bodies of water that we don’t want to be dropping on firefighters or near waterways and so sometimes we may bypass a closer water source to get to a more appropriate water source.”
All fire apparatus have the ability to draw water out of bodies of water, but water tenders are primarily used to haul large quantities of water to a fire line.
“Primarily we use water tenders to shuttle large quantities of water from a water source to fire engines that are actually pumping hose lays on that fire. This summer — because of the exceptional drought — creeks that normally would have water in them stand a good chance of not having pools deep enough for us to be able to draw water from. Some reservoirs, depending on their size, may go dry as well. Similar to the helicopters, they may require a longer turnaround time and that will mean that the incident commander, in order to maintain a steady supply of water on the fire ground, may have to order additional water tenders to ensure there is water arriving at the fire ground,” Nicholls explained.
And while water tenders may have a more difficult time finding water this summer, Nicholls said whatever water regulations that the State Water Board may issue, fire agencies and departments still have the ability to use whatever water is available to them in the event of an emergency.
“During an emergency, whatever water is available is available for our use,” he said.
While drought has the biggest impact on water supply, it also heavily affects vegetation in the form of drying vegetation out earlier than usual, which is a concern for fire crews.
Nicholls said this summer we may see more fuel-driven fires versus wind-driven fires since fuels are exceptionally dry. “Fuels are drier, therefore more prone to ignite when exposed to a source and then have the ability to burn with more energy due to the fuels being dried out. We have a potential, as the summer wears on, where we may have fuel-driven fires,” Nicholls said. “We’ve all had experience with the wind-driven fires over the last several years, but depending on how this summer continues to unfold, we have fuels at critically low fuel moisture levels.”
If the county’s morning marine lawyer and high relative humidity persists then that would be helpful for Sonoma County fire crews. The higher the temperature and the lower the relative humidity, the higher the fire risk.
“The one silver lining or the positive news is that because of the lack of rainfall this last winter, we don’t have as robust of a grass crop as we normally would have and so there has been areas where we have reduced available vegetation to burn and obviously that helps us on the fire control side once a fire ignites,” Nicholls said. “There are areas here in the county and across the overall unit that have been grazed by animals that have actually gotten down to dirt and so there is no grass available to burn and other areas, especially in our recent fire perimeters from the Lightning Complex and the Glass. While there has been some grass that has grown back, we have a reduced fuel loading available for a fire if it were to ignite in the same area this summer.”
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