Dry Wells in Jacksonville, FL: Subsurface Retention When Daylight Discharge Isn't Available
Dry wells (also called soakaway pits or seepage pits) are subsurface chambers that retain stormwater and release it slowly into surrounding native soil. They're the right answer when your lot has no daylight discharge available, when municipal stormwater tie-in isn't possible, or when site grading won't allow pop-up emitters to function. Gutter Pro installs engineered dry well systems — properly sized to expected storm volume, with engineered infiltration math, not "dig a hole and fill with rocks."
Quick answer: do you need a dry well?
Yes if:
- Your lot has no lower discharge point available (no slope to daylight, no street tie-in, no neighbor's swale option)
- Municipal stormwater regulations require on-site retention
- Pop-up emitters won't function because grade is too flat
- You're routing drainage that exceeds what a single pop-up emitter can handle
- HOA or community restrictions prohibit surface discharge to common areas
You don't need one if you have a viable daylight discharge or pop-up emitter location and the soil percolates well.
Dry well vs the alternatives
| Situation | Right system | Why |
|---|---|---|
| Lower point on the lot or street tie-in available | Daylight discharge via Schedule 40 PVC | Gravity discharge is simpler, cheaper, more reliable than retention |
| Slight grade available but no daylight | Pop-up emitter at the lowest accessible elevation | Releases at surface when pressurized, hidden when not |
| Flat lot, no discharge option, modest volume | Dry well sized to storm volume | Subsurface retention; releases slowly into native soil |
| Flat lot, no discharge option, high volume + crawlspace water | Sump pump system with PVC pumped discharge | Active pumping when gravity and retention aren't sufficient |
| Lot near marsh, intracoastal, or high water table | Sump pump system, not dry well | Dry well won't infiltrate when the water table is at or near the chamber depth |
What we install
Pre-cast concrete chamber
Cast concrete cylindrical or rectangular chamber with perforated walls, sized by required retention volume. Long service life (30+ years), highest load rating.
Modular plastic chambers
Polypropylene or HDPE chambers (Atlantis, Stormtech, or equivalent) stacked to achieve required volume. Lighter, faster to install, ideal where concrete crane access is limited.
Stone-filled trench dry well
Larger excavation filled with #57 stone, wrapped in geotextile fabric. Lower cost, suitable for smaller residential applications and where chamber installation isn't practical.
Inlet plumbing
Virgin-HDPE perforated pipe or Schedule 40 PVC feeds the chamber from the drainage system source (French drain, downspout, channel drain).
Overflow / emergency outlet
Pop-up emitter or secondary discharge for storm events that exceed chamber capacity. Prevents backup into the feeder system.
Cleanout access
Inspection port at grade for maintenance and verification of infiltration performance over time.
Why engineered sizing matters
"Dig a hole and fill with rocks" isn't a dry well — it's a hole that will fill with water and stay full. A properly engineered dry well requires soil infiltration testing, storm volume calculation, and chamber sizing based on the contributing watershed area.
NDS Certified installers verify the soil percolation rate, calculate the storm-event volume the system must hold, and size the chamber and overflow to handle both the design storm and the next-storm condition (when previous water hasn't fully infiltrated). Without that math, a dry well clogs or overflows the second time it's tested.
Cost guidelines
Dry well systems in Jacksonville typically run $2,000 to $10,000 installed depending on:
- Chamber type (stone-filled trench at low end, pre-cast concrete at premium)
- Required retention volume (driven by contributing watershed area and rainfall intensity)
- Excavation depth and complexity
- Soil infiltration testing requirements
- Permitting if municipal code requires it
Combined dry well + French drain feeder systems run $5,000 to $15,000. Final pricing locked after on-site walkthrough and soil testing.
