Undergrounding Timeline: What Happens Step-by-Step at Your House
SDG&E’s undergrounding projects move through a clear sequence — but most homeowners don’t know what actually happens or when they need to be involved.
This guide walks you through the entire process from the first markings on the street to final reconnection.
📝 1. Planning & Design Phase (You won’t see anything yet)
Before any construction starts, SDG&E and the City of San Diego spend months — sometimes years — planning:
surveying existing utilities
designing new underground routes
getting permits
coordinating with contractors
Homeowner impact: none.
You won’t see any physical activity during this stage.
🟧 2. Street Markings & Utility Locating (1–2 weeks before trenching)
Crews spray-paint lines and symbols on the street and sidewalks. These markings show the locations of:
gas lines
water lines
existing underground utilities
planned trench routes
You may also see small flags placed in yards or parkways.
Homeowner impact: minimal — this just means your block is getting close.
🚜 3. Trenching & Conduit Installation (1–5 weeks on your street)
This is when things become obvious. You’ll see:
asphalt cutting
open trenches
PVC electrical conduit being laid
steel plates covering open sections
contractor trucks and equipment
This is the noisiest and most disruptive part of the process.
Homeowner impact: street parking and access may be temporarily affected.
📦 4. Installation of Utility Vaults, Boxes & Risers (varies by neighborhood)
Crews place underground vaults or junction boxes that connect the new underground system. This includes:
concrete boxes in sidewalks or parkways
new service points
transformer pads (in some neighborhoods)
This sets the foundation for the final conversion.
Homeowner impact: low — but expect construction on sidewalks or lawns if vaults are placed nearby.
🔌 5. Pulling New Underground Lines (usually quick)
After conduits and vaults are in place, crews pull in the actual underground service cables.
This happens fast — often in a day or two per block.
Homeowner impact: none, except seeing contractor trucks and temporary equipment.
🔍 6. Home Inspections & Pre-Conversion Checks (this is where YOU matter)
Before SDG&E reconnects your home to the new underground system, they verify that your electrical equipment is:
safe
compatible
up to current standards
ready for underground conductors
If your panel is old or obsolete (Zinsco, FPE, Pushmatic), or has corrosion or clearance issues, they may require an upgrade before reconnection.
Homeowner impact:
This is the moment to have your panel inspected by an electrician so there are no surprises.
⛔ 7. Temporary Power Shutoff (same day reconnection)
On the day your home is converted:
SDG&E disconnects the old overhead lines
your power will go out
crews connect the new underground service
the meter is reinstalled
power is restored after the reconnection passes checks
Outages usually last a few hours.
Homeowner impact: short-term outage — plan to be home if possible.
🛠️ 8. Panel Upgrades (if required)
If your panel, meter socket, or grounding system fails SDG&E’s requirements, an upgrade is required before they reconnect you permanently.
Common reasons:
obsolete panels (Zinsco, FPE, Pushmatic)
insufficient amperage (60A or 100A)
rust/corrosion
clearance problems
incompatible meter socket
outdated grounding/bonding
An electrician handles the upgrade, permitting, and inspections.
🧹 9. Backfill & Street Repair (days to weeks after conversion)
Once the power conversion is complete, crews backfill trenches, patch asphalt, or pour new concrete.
This may happen:
immediately
weeks later
sometimes in multiple passes
Final resurfacing may take longer depending on city scheduling.
🏁 10. Street Restoration & Project Completion
The last stage includes:
final asphalt resurfacing
sidewalk repairs
cleanup
removal of overhead lines and poles
When the poles come down, you know the project is truly finished.
✅ Final Thoughts
Undergrounding is a long, multi-step process — but the part that affects your home directly is short and manageable as long as your electrical panel and meter setup are ready.
If you want peace of mind, you can send photos of your:
electrical panel
meter
overhead lines
panel location
…and get a quick evaluation of whether your home will pass SDG&E’s reconnection requirements.
