Surveyor Q..

[sleddriver]

What would you recommend for a DIY HO'er to use to record a simple topo grid in an area of say 75' x 38', for drainage purposes? (Nothing legal)

I'm exploring drainage options (regrade, install perforated pipe/then solid to daylight, dig 4' x 6' hole/well and install a flow-well, etc). Drainage needs to be corrected both parallel to concrete foundation on this side as well as perpendicular.

The low corner of the foundation is about 4" above the soil, right at a 90° corner. I need to drain this low spot to the front. I'm hoping for 1"/8' but might only get 1"/16'.

What I've done is establish a level line 68' long and make meas. every 4'. Total drop = 14"/68', but it goes up and down a few inches over a large tree root, rock walk, etc. I had to open a gate to go this distance.

Looking for something one guy can do. Have considered a water level on a yardstick and marking out a grid using sprinkler flags. I could go around corners like this as well. I'll draw it out to scale in either SketchUp or AutoCad.

How do you pro's do this? Grid size?

 

[MNgopher]

Laser Level. You'll still need to lay out the grid of points you want, but its the quickest way to get it done with one person without more expensive equipment. Usually can rent it not terribly expensively.

If you can get a buddy to help, you can do it with a hand level without too much trouble, but a tripod mounted level is (obviously) better.

If I were doing it professionally, and a one person crew, we'd be out there with a robotic total station or survey grade GPS (assuming terrain vegetation allowed it). Total station works fine if you are just working from a relative sense and don't have to tie into a benchmark for actual elevation (like "mean sea level"). Of course, we are working in AutoCAD Civil 3d, so downloading and dealing with survey data is just a normal day...

Grid size depends on what we are trying to accomplish. If you are working at a 0.5% grade (the 1"/16'), we consider that the bare minimum for a ditch grade to not get bird baths. 1% or more preferred. The flatter the grade, the denser the points need to be if you are going to tell much.

The water level will work just fine too.

 

[doitmyself]

MNgopher covered everything well.

On simple projects, I've resorted to using a string level on a few occasions. For example, on your project you could put wood grade stakes in every 10': 7 stakes in 70 feet. With a 14" total drop, that would be 2.0" inch drop on every 10' wood stake.

Google https://www.google.com/search?q=string+level&ie=utf-8&oe=utf-8 for lots of ideas.

 

[sleddriver]

Re: Laser level. Visible or no? The former would seem to be quicker than the later. With the later, if I understand correctly, at each point, I'd need to adjust the receiver up/down until it beeped, correct? Whereas with the former, I just read it off a site pole/yardstick, etc.

Re: Grade. I have the unfortunate combination of some grade sloping towards the house and being blocked by the house, from draining further down. Thus I need to intercept this water and divert it around the house.

I could go with regrading this area as it's not landscaped. Haven't yet decided though how best to integrate walkways, landscaping and drainage. Due to the native "soil" of clay, limestone and fist-sized river rocks, it's going to be tough going hand-digging. To get a BobCat in would mean taking down a section of fence, but that would be fast!

While digging a narrow trench for pipe and rock backfill could be easily done by removing the outer tines on a roto-tiller.

Re: Grid size. What would you suggest for 0.5% grade? For 1% grade?

Re: Water level. The bucket on one end, tubing on stick on the other has many advantages: One man use, no bending over, goes around corners, inexpensive to build, very reliable, no rental fee.

Coupled with a low concrete wall/curb to keep the storm runoff from the McMansion next door on his property, not mine, I'll be on my way to solving this problem.

Thanks for the response!

 

[sleddriver]

It's a bit more involved though when you have to go around a corner, out a gate and to the street. With simple things, I'll agree. Lots of bending over, meas. to ground, every 4'. Still it was a good exercise. Next I'll try a bucket water level.

 

[MNgopher]

Visible can be tough to work with outdoors - the range just isn't great under most lighting conditions.

As far as grid size, at 5 ft, your going to end up with around 140 pts for the size you described. At 10 ft, around 45 pts. If the grades are uniform enough, I'd go at 10 feet, and pick up any other breakpoints/highpoints/etc... Otherwise, you are in for a lot of work

 

[sleddriver]

OK. Good point. The more uneven the ground, the more GP's I need.

I've been reading up on Flo-wells (dry wells) and by regrading a small area and installing one of these, it could take care of surface water. Also with the soil being clay/limestone/river rock, going vertical and digging the hole about 2x the dia of the dry well shell will allow MUCH more surface area to allow the water to drain. I'll discard the clay/rock subsoil, refill with washed rock and line the pit with a tough landscaping fabric to prevent soil & fines from seeping in and clogging it up.