Monday, August 12, 2019

PG&E Facilitating Spread of Fire-prone Invasive Species by Opening Closed Canopy Forests

Ever try to do the right thing and have it all go horribly wrong?

PG&E is in the midst of some bizarre and ill-advised efforts to make communities safer from "Utility Caused Wildfire". While this is a goal I think virtually everyone can support, it comes down to asking "what are they doing to accomplish this lofty goal?". That is where the trouble starts.

The Paradise fire was caused when "a live wire broke free of a tower that was a quarter-century past what PG&E considers its “useful life.”" (from the New York Times). While PG&E claims to be changing to a stronger safety footing, even California Governor Newsom states "They have simply been caught red-handed over and over again, lying, manipulating or misleading the public,” summing the situation up simply as “They cannot be trusted.” (also from the New York Times).

Now I get to see this behavior up close and personal, as they attempt to mow a corridor through a closed-canopy second growth Redwood and Oak forest bordering my property.

The trick to fire safety in a Redwood Forest is one of ground clearance - keep no limbs for the lower 50' or so of the trunk, and fire simply cannot climb into the canopy. However, those trunks will only stay free of growth if they are in the shade, such as happens once the canopy of the forest closes. Remove the canopy, and those trunks become green with new growth and young branches. This then becomes not just a ladder fire path to the canopy, but a ladder fire path immediately adjacent to the PG&E power lines.

To engineer anything, you need to understand the system as a system. Forest is not a one-size-fits-all sort of affair. Chaparral and Savannah type woodlands are very different from closed canopy forests with little ground-level growth or light. How the forest and other vegetation will respond matters and needs considered in any plan to manage risks.

The forest is more than the trees.

In our case, a flammable and highly invasive grass is moving into the area called Slender False Brome. The local Open Space District is actively trying to limit the spread and in fact eradicate this species as it poses several risks, including fire.

Here is a photo of the species growing along one of our neighborhood roads where a natural tree fall created an opening in the canopy. The grasses with the nodding seed heads are the problem ones.

Standing on the same spot, looking the other direction, the view is completely devoid of this noxious species because the closed canopy prevents sufficient light from reaching the ground to support growth of the grass.

Opening power line corridors to the sky is inconsistent with California Public Utilities Commission guidelines (which recommend a small radial distance be cleared from the lines, not clearing to the sky).

There is an adage about "the road to ... being lined with good intentions". Certainly this approach to closed canopy forests is going to line the area under the powerlines with easily ignited grasses that are tinder dry in late summer and fall, when fire risks are highest. It might even look like the road to ... should a line fall into such perfect kindling.

The kindling aspect aside of Slender False Brome, creating paths for rapid and deep spread in the largest forest lands in San Mateo and Santa Cruz counties seems unwise at best, and seriously negligent at least in my eyes.

No comments:

Post a Comment