Anybody know how the Park burn area is doing?
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The runoff this morning in Chico Creek was dark dark brown, but there wasn’t a lot of debris coming down.
I was out in Cohasset today looking at runoff in some really high-severity burn areas in Upper Mud Creek. The ground was thirsty, and I don’t think the volcanic soils are very prone to hydrophobicity - I didn’t see much overland flow in areas where was deeper soil, and in the harsher lavacap areas in the foothills, the water was concentrated in areas where it always runs off (hardly any soil to erode in the first place).
Cohasset has likely gotten a foot or more of rain since Wednesday, but all in all, I was surprised not to see more surface flow in the areas of hot burn. Things looked more stable than I’d been anticipating. Most of the places with runoff were places where old roads, trails, or culverts on roads farther upslope were concentrating the flow.
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I suppose with a name like Mud Creek one would not be surprised if it gets dirty
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A lot of ash colored water and debris moving down the channels. Much higher flows in the smaller streams which is indicative of a burn scar. For much of the event Big Chico creek was running higher than Butte Creek… not a normal reaction for a storm series like this one. The debris moving down the creeks is impressive and will be a long term issue for the areas downstream of the scar.
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Do you suppose as the roots in the dirt die off from the burn, that the soil will be weaker next fall leading to more slides, etc. or is that really a thing?
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Following on the @norcal74 post about the differences between runoff in unburned (since 2021 Dixie Fire) Butte Creek vs Big Chico Creek (2/3 of upper watershed burned in Park Fire):
In the hydrographs, you can really see how ‘flashy’ the runoff was in Big Chico Creek, with the peak flow responding quickly to our heavy rains on Thursday night, dropping quickly after the pulse of precip, and cresting again Friday night.
Butte Creek came up slower, stayed more steady once the rains fell off Friday, and responded slower to the next pulse of rain Friday night.
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Wanna talk about runoff, imagine is there was a legit snowpack on the ground when the warmish AR came thru last week! Am i the only one pondering the “what if’s” about a shift to periods of multiple AR storms (like what occurred Dec 2022 thru Jan 2023) and what that will do to our system/infrastructure etc? I don’t think its unreasonable to consider that those back to back to back events will happen again - especially as the planet continues on its current warming phase - and wont they will be much deeper/wetter/longer lasting than what nops just experienced?! #realitycheck
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What we see in the post fire environment is a landscape that is more susceptible to flooding caused by high intensity precip events. That is not to suggest that a lot of rain over a longer duration will not cause problems. The rain on snow events tend to really impact the larger drainages, and when you think about it the event has an impact but not perhaps as significant as we believe. Based on a 1:10 snow water equivalent we see perhaps a 25 to 50 % increase in run off from a rain on snow event. That can be impactful based on antecedent conditions but the greatest impacts on burn scars tend to be more terrain and precip intensity driven. Steep slopes, head walled canyons and narrow drainages are really susceptible to flash floods. High intensity rain on those slopes is the triggering mechanism.
Soil type is another contributing factor. Sandy loam is more prone to rapid runoff compared to clay soils.
The main situation which shouts watch out is heavy rain over a short period of time from either enhanced convection or a NCFR. The most likely scenario for the Park fire is a system which drops several inches in the watershed and then at the tail end of the storm an Narrow Cold Frontal Rain band develops and torrential rain falls on saturated soils. That would cause an extreme runoff event. What was very evident in this past system was that fire debris will be an issue for years downstream of the fire. Burned logs, branches and debris will continue to plug culverts and bridges can cause flooding.
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I’ve heard similar things about the 1997 storm - rain on snow was less of a factor than the shear volume of precip (something like 40+ inches in 6 days) up around Bucks Lake.
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There were several rain on snow events around here on the I80 corridor last couple of years and despite the dire predictions, all it did was soak into the snowpack and make it heavier. Must be a specific set of circumstances that lead to the mass melt that has sometimes happened.
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Documented tornado touchdown down in Scotts Valley, Santa Cruz Co. at approximately 1345. Multiple vehicles overturned with unreported injuries. I’m sure the social media videos will be out there.
https://kion546.com/news/2024/12/14/tornado-flips-cars-upside-down-in-scotts-valley-injuries-reported/
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I’m sure you noticed that is Calfire B1719 pickup. He was trapped inside for a bit.
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These tides are way-huge. How u train for this incident type?!
911 - “Whats your emergency”
Caller - Uhm, my restaurant just fell into ocean and so did basically a small city block!
911 - Can you repeat that please…
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