Hundreds of Gallons, One Storm, Right at the Wall
Downspout
Extension
Systems in Maryland
A typical Maryland roof sheds hundreds of gallons of water in a single rainstorm, all discharged at whatever point the downspout ends.
When downspouts discharge at the foundation, all of that water saturates the soil directly against your basement wall. Underground extensions to a pop-up emitter 10 to 15 feet out are one of the highest-return drainage investments you can make.
Why Discharge Location Matters
A Few Feet Makes All
the Difference
Most basement water problems have a surface water component. Even a well-waterproofed foundation can be overwhelmed when a downspout discharges 50 gallons at grade right next to the wall after every storm. In Maryland's clay soils, that water doesn't absorb quickly, it pools, saturates the backfill zone along the foundation, and eventually finds its way through wall cracks, window wells, or the cove joint at the floor.
The standard corrugated plastic downspout extension, the accordion tube that flops across the lawn, is better than nothing, but it's often too short, gets displaced by lawnmowers, and still discharges within a few feet of the house. Underground rigid-pipe extensions connected to pop-up emitters discharge water 10 to 15 feet from the foundation and are invisible when not in use.
Underground rigid pipe replaces the surface accordion tube that gets displaced by mowing and still discharges too close
Signs Your Downspouts Are the Cause
How to Know If Downspouts Are
Contributing to Basement Problems
These signs point specifically to roof runoff as a contributing source, distinct from groundwater or a structural issue.
- Water appears in the basement during or within 30 minutes of rain
- The wet wall is on the same side as a downspout discharge point
- Downspouts terminate within 4 feet of the foundation wall
- Visible splash erosion or mulch displacement directly below a downspout
- Gutters overflow at corners, sending water directly down the wall
What's Included
OBW's Downspout
Extension Services
One of the lowest-cost, highest-return fixes in exterior drainage, done underground and out of sight.
Rigid Underground Piping
Schedule 40 or SDR-35 PVC pipe buried below grade, sloped correctly, replacing surface accordion tubing.
Pop-Up Emitters
Discharge 10 to 15 feet from the foundation, opening under pressure during rain and closing when flow stops.
Backflow & Rodent Prevention
The emitter design prevents both backflow into the line and rodent entry when the system isn't actively discharging.
Multi-Downspout Tie-Ins
Where downspouts are close together, we tie them into a single underground line to a shared discharge point.
Dry Well & Storm Drain Connections
Handled where grade doesn't allow daylight discharge, or where municipal rules permit a storm drain tie-in.
Written Workmanship Guarantee
Every downspout extension system is backed by a written workmanship guarantee. Ask your inspector for the terms that apply to your job.
The Process
How OBW Installs a
Downspout Extension System
Identify each discharge point. Trench and pipe. Set the emitter far enough out. Verify it works.
Discharge Point Assessment
OBW identifies where each downspout currently discharges and how close that point sits to the foundation.
Trenching & Pipe Installation
Rigid PVC pipe is buried below grade and sloped from each downspout toward its new discharge point.
Emitter Placement
Pop-up emitters are set at a lower elevation, 10 to 15 feet from the foundation, and tested for proper opening and closing.
Verification & Restoration
The system is tested with water flow and the trench line is restored with topsoil and seed.
Photos From the Field
Job Site Photos
A closer look at the equipment, materials, and job site conditions involved in this kind of work.
Honest Answers
Downspout Extension Questions
from Maryland Homeowners
Call (410) 879-3360 if your basement gets wet shortly after it rains. Our inspectors will check your downspout discharge points on the spot.
Why does where a downspout discharges matter so much?
Most basement water problems have a surface water component. Even a well-waterproofed foundation can be overwhelmed when a downspout discharges 50 gallons at grade right next to the wall after every storm. In Maryland's clay soils, that water doesn't absorb quickly, it pools, saturates the backfill zone along the foundation, and eventually finds its way through wall cracks, window wells, or the cove joint at the floor.
Isn't a standard corrugated downspout extension good enough?
It's better than nothing, but it's often too short, gets displaced by lawnmowers, and still discharges within a few feet of the house. Underground rigid-pipe extensions connected to pop-up emitters discharge water 10 to 15 feet from the foundation and are invisible when not in use, a meaningfully different result for the same basic idea.
What exactly does OBW install?
We connect each downspout to a rigid Schedule 40 or SDR-35 PVC pipe buried below grade, sloped to a pop-up emitter set at a lower elevation in the yard. The emitter opens under pressure during a rainstorm and closes when flow stops, preventing backflow and rodent entry. Where multiple downspouts are close together, we can tie them into a single underground line to a shared discharge point. We also handle downspout-to-dry-well connections and downspout-to-storm-drain connections where municipal rules permit.
How do I know if my downspouts are contributing to a basement problem?
Common signs: water appears in the basement during or immediately after rain (within 30 minutes), the wet wall is on the same side as a downspout discharge point, soil near the foundation stays saturated for days after rain, downspouts terminate within 4 feet of the foundation wall, you can see splash erosion or mulch displacement directly below a downspout, or your gutters overflow at corners and send water straight down the wall.
Is this usually a standalone fix or part of a bigger scope?
Downspout drainage is often the first thing OBW addresses as part of a broader waterproofing scope. It's low cost, immediately verifiable, and frequently eliminates or reduces the severity of other water intrusion problems. We assess all exterior water sources before recommending a scope. Every installation is backed by a written workmanship guarantee, terms vary by service, ask your inspector.
Why Oriole
Why Maryland Homeowners Trust
OBW with Downspout Extensions
Low Cost, High Return
Downspout drainage is one of the most cost-effective fixes OBW installs, and often reduces the severity of other water problems on its own.
Built for Maryland Clay
OBW routes discharge far enough from the foundation to matter in Maryland's slow-draining clay, not just a few feet past the wall.
No Subcontracting
OBW's own crew installs every trench, pipe, and emitter, in house, start to finish.
Family-Owned Since 1953
Founded by Frank Pirog Sr. in 1953. Amber Pirog leads the company today. Written workmanship guarantee on every installation.
Reviews
What Our Maryland Neighbors Say
Address the Source, Not Just the Symptom.
Getting Started on Your
Downspout Extension System
Downspout drainage is often part of a larger solution. We'll assess all exterior water sources before recommending a scope.
Free Inspection
OBW checks every downspout's discharge point and how close it sits to the foundation. Free, no obligation.
Written Extension Plan & Quote
You receive a written quote specifying the piping and emitter placement your home needs, before any work is scheduled.
Installation & Verification
OBW's crew trenches, pipes, and tests the system before restoring the lawn. Written workmanship guarantee issued upon completion.
Basement Gets Wet Right After It Rains?
Free inspection. We check every downspout discharge point.
Family-owned since 1953 · MHIC #4247 · Written Workmanship Guarantee