12d • General discussion
Grading a subdivision: What your dirt contractor will not tell you
Grading is the first thing that happens on site and the last thing most developers understand.
Here is what you need to know.
When you grade a subdivision, you are doing three things at once:
1. Setting your road profile (finished grade of the street)
2. Establishing lot pad elevations (where homes will sit)
3. Creating your drainage pattern (where water goes when it rains)
If you get any one of those wrong, the other two break.
Real example: On the Conway Mile3 project, earthwork came in at $95,000. That is for 9 acres of relatively flat South Texas land. The site had maybe 3 feet of elevation change across the entire property.
Why so much? Because flat land is actually harder to grade than sloped land. You need to CREATE slope where none exists. Every road needs at least 0.5% longitudinal grade to drain. Every lot needs to slope away from the house toward the street or a swale.
Common grading mistakes:
Not balancing cut and fill. If you haul in or haul out dirt, that is $15 to $25 per cubic yard of hauling cost on top of the earthwork. A good engineer designs the grading plan so you use the dirt you cut to fill the low spots.
Ignoring existing drainage patterns. Water has been flowing across this land for decades. If you block a natural drainage path without providing an alternative, you will flood someone downstream and get sued.
Not compacting properly. Your compaction spec is usually 95% Standard Proctor for road subgrade. If your contractor is not testing every lift, you are gambling on your road holding up.
The takeaway: grading drives everything. Get it right first.
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Grading a subdivision: What your dirt contractor will not tell you
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Raw dirt to shovel ready. A licensed Civil Engineer breaks down real projects, real numbers, and lessons from the field. www.ferest.dev
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