Oregon Hikers

Koda wrote:The only event within the BOW was the last forest fire.

Are you saying there were no slides in the BOW Wilderness portion back on the 11/12th? I think not. Just wanted to check. But if you are, how does lidar show that?

mcds wrote:

Koda wrote:The only event within the BOW was the last forest fire.

Are you saying there were no slides in the BOW Wilderness portion back on the 11/12th? I think not. Just wanted to check. But if you are, how does lidar show that?

I don’t have any way to view or know if any landslides occurred within BOW prior to 2/13/2014 (Date of photo), no that’s not what I am saying just the forest fire a couple summers ago...


I have to backpedal a bit on the lidar statement, I should have said Google Terrain shows no roadbeds. I assume that the Google Terrain feature uses lidar technology but I have never confirmed that….

I know there used to be a road to first swampy area with the log crossing on Dickey creek trail. Not sure about any others.

mcds wrote:Assuming the road density in the upstream watershed of the Clackamas is similar to the road density in the Collawash watershed, then mkrochta's photo shows that forest roads don't necessarily destabilize the terrain to a critical extent. It could be that the road contractor for the Collawash goofed, or skimped. Or it could be the Collawash roads were built in a different year under different best-practices. Or ....

I just want to jump in for a sec, and then try to respond to some earlier posts when I'm back on Friday. Not the best internet connection so here goes...

I wanted to share another resource on subwatersheds in the MHNF that seems to be relevant to this conversation:http://www.fs.usda.gov/Internet/FSE_DOC ... 036592.pdf. This, along with the Collawash WA that I linked earlier on, contains some great information on how the Collawash fairs aquatically compared to other subwatersheds in the forest. If folks are looking for turbidity data specifically, I suggest visiting the DEQ website.

Below are the criteria the USFS uses to score aquatic risks in subwatersheds, along with a graph that then ranks to top subwatersheds in MHNF in regards to their aquatic risk.

Also, I just want to flag that at the Estacada meeting tonight, the USFS's map of roads in the Collawash they plan to remove, or have removed already, did not differ significantly from mine (I retained the road to Whetstone and other trailheads). They based these removals primarily on the aquatic risk the roads pose.
So please participate in the TAP! http://www.fs.usda.gov/detail/mthood/ho ... RD3818668

mcds, I accept your point on weighting flows from sources. I also accept your point on the possibility of a one time event affecting the rivers. But the two offset in terms of probabilities. That is, the Clackamas with a larger drainage area has a higher probability of a one time event than the Collawash does, other things equal. Still, that's probabilistic, not evidence of sources on a particular day.

I stick with my point that large events are what sedimentation is about -- not low flow rate days. High flows carry loads.

I was sort of bummed they decommissioned the road that went be Riley Campground on the way to the Ramona Falls and Burnt Lake trailheads. I used to walk on that in the winter. Nice loop with the Horseshoe Ridge trail. Nice cross country ski route. But there was some abuse by people in vehicles.

Yeah, seems kind of expensive. They could just decommission the first part so it's impossible for any motor vehicles, and any stream crossings that might hurt fish. They could do a partial decommission on a number of roads for the same cost as a complete decommission of one road.

Do you recall when that road was decommissioned? It is still shown on many maps.