Recommendations to shoot / determine a grade on proposed road

[JamesHW]

Our makeshift surveying setup consists of a decent sighting compass that has a built in bubble level screwed onto an old heavy duty photo tripod that has spikes in the feet. Combined with a friend a 50 foot tape and a story pole we plan to layout some fences and do a survey of a small pond area.

Used to overlay all sorts of topo maps in photoshop to get an idea how our property lines traversed a couple of ravines. Lately LiDAR imagery has become available and is a real game changer. Details of the every little change in elevation are clearly visible like for example a 3 wide x 2 deep x 20 long drainage ditch from the 30痴 put in the dry out (unsuccessfully) some low areas is clearly visible.

 

[Jim Nelson]

Same here. I have talked to staff at County Fire and they advised about a number of things - absolute minimum tank size is 2500 gallons - larger perhaps if your water production is very, very low. And said it has to be fitted with a 4 1/2 inch special outlet for connection to a fire hose, and fire trucks need to be able to get very near to it. Staff there was very helpful - willing to spend time explaining it all and making recommendations re sizes, best plumbing options etc.. We are planning on going with a 4000 to 5000 gallon tank.

There are no hydrants anywhere - nearest town is 25 miles away. I always consider County Fire staff, County staff and others as assets and resources to help me get it right. But not everyone up here agrees with that.

I truly believe that one of the best things about the state is our fire people, in my opinion they are right up there with the best in the world.

 

[pmsmechanic]

I truly believe that one of the best things about the state is our fire people, in my opinion they are right up there with the best in the world.

They get a lot of practice!

 

[quicksandfarmer]

Oh sure, now the nerds come out of the woodwork!

Without nerds there would be no GPS!

 

[beowulf]

UPDATE: Well, I found a very useful site to determine elevations. I do not know how accurate it is, but by using it to check the known elevation at the home site it is spot on there. Anyway, you can pull up an aerial shot of your property - zoom in to whatever spot you want to check and click and it will give you the elevation. Click anywhere on your property and instantly see the elevation.

Comparing the smart phone readings with those in this program: It seems the smart phone calculations were off a bit (assuming this program is accurate/more accurate)and gave slightly different readings on repeated attempts. The cell phone readings had the elevation at the starting point of the proposed driveway at between 2370 and 2380, and the elevation at the end point at between 2410 and 2420 (I found out later that my son-in-law rounded!). The program I just used has the starting point elevation at 2362 and the end point on the hill at 2432. But with the phone calcs we adjusted the top figure, i.e., took 6 feet off of the reading to accommodate the amount we estimate will be taken off the crown of the hill - so if we take that same 6' off of this programs elevation we get 2424 at the top - pretty close - and I can't say for certain we were standing on the precise same point at the top.

Then I used the distance measuring feature on google maps and it seems we had the distance about right at 540 feet - the map feature had it at 536 feet - and again, it is difficult to measure from the precise same locations.

Anyway, it seems that after deducting the 6' grading off of the crown for the pad, the rise calculated with this program is about 64 feet over a distance of about 540 feet.

BTW - the topo program I used is:

Elevation Finder - Topographic map - Altitude map - MAPLOGS

Thought I should share this - found it useful and interesting to use. Note: use the hybrid map on the program.

 

[dodge man]

That puts you just under 12%, 11.85% to be exact.

 

[Tinhack]

When I lived in Ohio, I thought my 6% grade driveway was steep in the winter. As a city-slicker, I had my Craftsman lawn tractor decked out in snow gear. It was still a tough job getting to work some days. The North Coast snow belt can be brutal during the winter months.

Be sure to include water drainage in your driveway plan.

 

[beowulf]

That puts you just under 12%, 11.85% to be exact.

Thanks Dodgeman, good to know. I am guessing that the initial part will be a bit over that with the later part under that - the contractor will have to determine all of that.
I need to learn about the % of slope calcs vs the degree calcs - at first I thought they were the same. A bit confusing until you begin to look at it.

 

[dodge man]

For % slope, just take the amount of elevation difference and divide by the distance and multiply by 100. 64/540 x 100=11.85% in your example above. You should be using the horizontal distance to, but probably in your case for rough figures you can use the slope. In your example the difference between horizontal distance and slope distance would be about 4 feet.

I believe the degree of angle is a little less than 7 degrees, I do not have a very good calculator handy. It tales a knowledge of trig functions to calculate that.

 

[beowulf]

Dodgeman, thanks again for the formula. I was aware the distance on the upslope was different (slightly longer) but was not sure by how much. Very useful information. The grading contractor wants to wait until we have some rain (dirt is hard and doubt he wants to fight the dust either) and he can't get to it anyway for a while, but at least I now know what is doable to comply with County Fire requirements.