Leveling part of a hill iwith a 25% Slope- see atttachments

[Ocean2026]

There's a hill that ascends 850 feet in height- But see attached. want to level the first 500 feet which starts from 200 ft above sea level and goes to 360 ft above sea level. The land is in Skaokawa WA and one can see the Columbia River - Vista Park at the bottom. The entire hill - mountain goes up 800 feet. It has young trees and not sure if there is a landslide risk- probably not.

1. Is this too steep to do safely say in a D2 or D4? ( How do I stop from rolling over until I end up in the river?)

2. What methods should be used to distribute the dirt relatively equally?

3 Any other tips

 

[Birdhunter1]

Your best bet might be to call an excavator and tell them they can have as much fill dirt as they want as long as this is leveled. Even at that though that is alot of hillside to move and try to level.

 

[Ocean2026]

Thanks there's plenty of dirt in that area-- I think a backhoe would be better than a dozer though.

 

[bcp]

Your best bet might be to call an excavator and tell them they can have as much fill dirt as they want as long as this is leveled. Even at that though that is alot of hillside to move and try to level.

Is the quarry just east of you still active?



Bruce

 

[RickB]

You are proposing a 160 vertical cut partway up an 850 foot slope? Am I understanding that correctly? How wide is the area you want to excavate? Sounds like a massive project to me.

 

[Rebeldad1]

big excavator... big bucks... but a great view? pics when you get up there next time.

 

[Ocean2026]

I have some great pics already . The upper part has the best views, if this doesnt upload sfischerlaw@gmail.com and I will send

Rick I basically want to somewhat level am acre mabe 60,000 square feet - would that not be doable in a solid week 7 days of work? [

 

[Ocean2026]

Bruce its still there -not sure how active.

 

[Jchonline]

With just a dozer? Why not get a quote for it from a few contractors with a good reputation so you have some idea if the time involved to do it right?

 

[ericm979]

Wow, nice views.

You're going to end up with a super steep 160ft high slope behind your new house or whatever you're going to put on the new flat space. That sounds like it could be a landslide hazard especially if you're removing material from the bottom of an existing slide. I'd want a geologist's report and maybe an engineer for the project. You'll probably need those for permits anyhow.

BTW, big earthquakes have happened in the pacific northwest. There was a 9.0 on the Cascadia fault in 1700.

 

[Egon]

Best be getting it designed by an Engineer. The slope stability is critical, both on the cut side slope and the fill side slope.

Cuts of this type will usually be started from the very top with dozers. The dirt is pushed over the side as the side slope is cut And gradually forms a flat area that gets wider as the cut gets deeper.

Forget the D2 or D4. Start at a D9 or bigger. Well maybe smaller with an angle blade to initiate the cut. The dozer works on a flat area and pushes the dirt over the downhill side. The flat area will slowly get wider as the cut depth increases. If a dozer does go over the side drop the blade, try to get facing straight down hill and make sure your seat belt is fastened. A dozer with winch may pull you out and up if the dozer is just tilted over on a soft edge.

Also consider road access.

 

[LouNY]

How far down to bed rock,
is that hill a rock upthurst.
Depending on the soil conditions it might be decent to do with a grader,
or it could require drilling and blasting.
Too many unknowns to make a judgement call.
Also if you are in an area that is so regulated that an engineer and engineered plans are required your cost just went thru the roof.

 

[Egon]

Also if you are in an area that is so regulated that an engineer and engineered plans are required your cost just went thru the roof.

The costs may also be significant if all slides down into the river.

 

[CADplans]

That much dirt moving should easily cost over $100,000,, and is WAY more than a week,,

You will be using drills, and explosives,, just to loosen the material, even if you do not hit bedrock.

I removed 4 feet of dirt off 1.5 acres (about what area you are talking about) with a TD9 IH dozer,,
that took an entire summer,, (back in the 1970s)
We were moving only clay, no sand, no rock.

Yea, I used an old dozer,, but, you want to move an awful lot MORE material than 4 feet,,,

 

[Mat4644]

If you level a 500 foot section the transition section will be steeper than before and an erosion and slide risk. You need at least professional planning to determine what is safe and LEGAL.

 

[Diggin It]

is that hill a rock upthurst.

Somebody finally got there. OP might only find a few feet of dirt that can be moved.

 

[Ocean2026]

Thanks The Washington Department of Natural Resources has a small landowner program and they are supposed to provide assistance. The Alder Trees grow so fast up there and really can only be knocked off in July and August otherwise they grow back rapidly.

I dont think moving some earth down the hill a few hundred feet would cause a landslide and the vegetation cover is thick but will check. The earth is soft.

I still don't know whether a backhoe or a bulldozer would be best.

 

[Diggin It]

I still don't know whether a backhoe or a bulldozer would be best.

You don't seem to be understanding the scale and scope of this task. A fleet of specialized earth moving machinery with a skilled crew 'would be best'. You don't move mountains with a backhoe.

 

[Citydude]

The yardage you are contemplating moving and your question of how not to roll a dozer says hire a pro.

For reference, a D10r dozer will move 400 yards of loose material an hour by slot dozing. For further reference say the dozer cut a 20 foot deep slot the width of the dozer, and pushed it 160 feet. That’s only 2400 yards. I used to operate dozers in a mining environment.

Your going to need a bigger boat.....

 

[RickB]

You don't seem to be understanding the scale and scope of this task.

Exactly. Or the potential ramifications thereof.