A (very) brief analysis of North Coast stream flow data

[Dustin Revel]

Hey everyone! I haven't really posted here in a while, but stopped by and got a laugh out of the swing north thread going on below... Anyways that got me thinking about some things which led to me writing a program to find the 7 day period with the lowest flow in a year, then calculate the average during that 7 day period and save it to a file, which i opened in excel and made the a few scatter plots. the streams I ran through the program are: Smith River, Redwood Creek, and Mattole river. I picked these because they are not dammed (or are they?). long story short it appears our rivers are decreasing in summer flow (except the Smith River)... personally, I blame pot farmers, but draw your own conclusions. If you have any questions let me know.
I don't want this to turn in to a statistical piss-fest so take them for what they are and note the small R^2 value.

[Awood]

Nice work. It would be interesting to add rain totals to the graph. Is it possible the water table is decreasing due to less overall rain (global warming)?

Btw: pumping water from the system and ground has a significant impact but it's pretty hard to quantify. The Russian River is a perfect example. Massive ground water pumping to support grapes and a wine industry in complete denial.

[Dustin Revel]

Nice work. It would be interesting to add rain totals to the graph. Is it possible the water table is decreasing due to less overall rain (global warming)?

Btw: pumping water from the system and ground has a significant impact but it's pretty hard to quantify. The Russian River is a perfect example. Massive ground water pumping to support grapes and a wine industry in complete denial.

I'm sure it is possible to add rain. Ground water pumping is difficult to quantify (i believe it is a finite difference type problem), but most pot farms pump directly from streams (surface water). This has an immediate impact on flows.

We also have no idea what the flows would have been completely unaltered, before a giant reduction in forest biomass. it is possible the decline is due to an increase in forest biomass.

[jcanger]

Yes, pot farmers are contributing to the low flow problem on north coast streams. They're not the only reason; but they're not helping the situation. Their operations divert water that would otherwise make it to the rivers you plotted. Their diversions cause lower flows, and also exacerbate water quality issues within those watersheds as less water to dilute discharges to main stems. Some of the state environmental agencies are looking into the issue. But can't fault them for not wanting to issue a cease and desist order to cartel senturies guarding a couple hundred plants. Tough issue.

[Tim P]

What's this? Advancing a proposition by using actual data?

This is the steelhead forum, dangit! You are supposed to make claims without resorting to any data whatsoever in here!

I don't know the first thing about hydrology nor the specific land use changes that have occurred over time in those hydrologic units, but it seems reasonable that groundwater recharge or vegetation changes resulting from land use changes could also affect the catchment water release rates. No doubt surface water diversions will clearly alter surface water flow, but how much weed was being grown up there in the 50s?

If you can find the matching rainfall records for those HUs, that same (low-flow) data would be interesting if re-scaled to cumulative rainfall in the N-month period prior to the low flow - that would at least correct out any aliasing due to climactic changes in the source (i.e. rainfall) over the data period.

cheers

[Grassgrower]

Check the cimis.water.ca.gov site. You should find all the info you want.

I haven't been able to find rainfall data for each watershed dating back to the 1950's, but it could be out there or I might be able to create a model and extrapolate back to the 50's.
I don't know enough about hydrology to really understand why, but the Smith River is not decreasing while the mattole and redwood creek are. If the flow reduction were tied to rain, it seems like the trend should appear in all streams at least over 60 years. I can play with this more when I have time.

[Dustin Revel]

Check the cimis.water.ca.gov site. You should find all the info you want.

I don't see any data from Humboldt County. I think NOAA will be my best bet.

http://wwwcimis.water.ca.gov/cimis/f...ionListData.do

[Ben J]

Cool analysis. There's no doubt that the watersheds of Redwood Creek, the Mad, Eel, and Mattole are experiencing some very intensive marijuana cultivation that has grown exponentially. As mentioned, the Mexican cartels are no longer the main player out here. It's locals, BroBrahs from SoCal and out of state, the Hmong from Eureka/Fresno, and Russians and eastern europeans that have moved into the area and I suspect from the news that many of these groups are related to organized crime. The Trinity Pines subdivision located to the Northwest of the HWY 3 and 36 junction is really the crown jewel of outrageous growing practices. Earlier this fall there was a raid that consisted of 100+ law enforcement agents and apparently over 20 parcels raided. Word is that many people cannot even drink the groundwater because of the level of toxins. It's really hard to believe what is going on out in the hills, but nothing is surprising anymore.

http://lostcoastoutpost.com/2013/oct...rossest-busts/

Also, not related to fly fishing but there have been some truly bizarre acts of violence going on out here related to weed. The Garrett Rodriguez story is one of trimmers, murderers, and Alderpoint vigilantes seeking "Hill Country" Justice.
http://lostcoastoutpost.com/2013/dec...onfirm-connec/

If you think the Steelhead forum is crazy then don't even bother with the comment section on LOCO outpost.