Last updated: October 11, 2026. General information, not engineering advice. Local codes and soil conditions vary.
“Exterior drainage” means any system that collects water outside the house and carries it away before it reaches the foundation. It ranges from a $20 downspout extension to an excavated footing drain. The sensible approach is to work from the cheapest, most surface-level fix down to the most invasive, and stop as soon as the problem is solved.
The short answer
Madison’s flooding guidance lists the order as grading and gutters first, then exterior drainage, then interior drainage. Exterior drainage is the most expensive option but also the most effective, according to the same source, because it intercepts water before it reaches the wall. It involves excavating around the foundation and installing drain tile along the footing, leading to a sump or to daylight.
The layers of exterior drainage
| Layer | What it does | Typical fix |
|---|---|---|
| Roof water | Keeps rain from landing next to the wall | Clean gutters, extend downspouts (5 to 10 feet per Pro Builder) |
| Surface grade | Sends rain away across the soil | Regrade to about 6 inches of fall over 10 feet |
| Surface collection | Captures water that pools | Swales or gravel-filled area drains piped away (Pro Builder) |
| Shallow subsurface | Intercepts water in the yard | Yard French drain; LawnStarter lists $10 to $65 per foot |
| Footing drain | Drains water at the base of the foundation | Excavated drain tile along the footing, to a sump or daylight (Madison) |
Surface fixes
Fixr lists gutters and downspouts at roughly $3 to $30 per linear foot, which is a small fraction of the cost of drain tile. If water is ponding near the house, a swale or an area drain may solve it without any digging near the foundation.
Yard French drains
A yard French drain is a trench filled with gravel and a perforated pipe, which collects water and carries it somewhere safe. LawnStarter puts exterior drains at $10 to $65 per linear foot, with shallow drains costing less than footing drains, which sit at least a foot deep. It also notes that soil type, access, pipe and gravel, permits and add-ons such as dry wells change the price. A yard drain helps when surface and shallow groundwater is the issue, and it needs a place to discharge. A shallow, soil-covered version placed between the water source and the house is often called a curtain drain; see curtain drain vs. French drain for how the terms differ.
Footing drains
A footing drain sits at the bottom of the foundation wall and carries away water that reaches the base. Installing one on an existing home usually means excavating to the footing, which is why it is the expensive end of exterior drainage. Madison describes the drain tile as backfilled with gravel or sand, or with a drainage mat and on-site soil, and says the drains must lead to a sump. Pro Builder lists letting dirt wash into footing drain gravel as a recurring mistake, so good backfill and filter fabric matter.
Where the water goes
- Daylight. The pipe ends in a lower part of the yard where water can flow out by gravity.
- A sump pit and pump. Needed when gravity cannot carry the water away (LawnStarter). See our sump pump buyer’s guide.
- Storm sewer or street. Madison notes curb or storm inlet discharges require an excavation permit and a pre-qualified contractor. Check local rules.
When exterior drainage is worth it
- Water arrives at the foundation from the soil side despite good grading and gutters.
- The wall itself is leaking and interior work would only collect the water after it passes through.
- You are already excavating, or the foundation is exposed.
- You plan to stay in the home a long time. This Old House recommends exterior work for persistent flooding and for homeowners planning to stay long-term, and mentions clay soils where hydrostatic pressure is a bigger issue.
When to choose something else
Exterior work is disruptive. This Old House says excavation-based work takes at least one to two weeks, compared with three to five days for interior drainage, and can mean tearing up patios, decks, driveways or irrigation. Interior drainage can be a better fit if the outside is inaccessible. Our interior vs. exterior guide weighs the two, and the French drain cost guide shows prices.
What to ask a contractor
- What is causing the water, and how did you confirm it?
- What depth and length will the drain run, and where will it discharge?
- What pipe, gravel and filter fabric are included, and how will you keep soil out of the gravel?
- Is a permit required, and who pulls it? Does the quote include utility locating?
- Does the price include restoring landscaping, concrete or sod?
- What does the warranty cover?
Compare at least three itemized quotes, and see how to hire a contractor for licensing and deposit rules that vary by state.
A worked example: water pooling beside the house
Suppose water collects along one side of the house after storms. First, fix gutters and extend downspouts, which are the cheapest steps. Then regrade so the soil falls about 6 inches over 10 feet. If it still pools, a 100-foot yard drain is in the range LawnStarter gives for exterior drains: $1,000 to $6,500, plus a permit that LawnStarter lists at about $58 to $225 where one is required. If water is entering the basement itself despite all that, you are in footing drain or interior drainage territory, which costs considerably more.
Signs your exterior drainage is not working
- Water pools next to the foundation or in the yard for a day or more after rain.
- Soil washes out around downspouts, or mulch and gravel migrate toward the wall.
- Damp or stained basement walls after storms.
- A drain outlet that stays dry during heavy rain, which may mean the pipe is clogged or broken.
- Settling soil along the foundation that creates a dip toward the house.
Related guides
How we put this guide together
This guide was drafted with AI assistance and then edited for the site against the public sources listed below. We are not engineers or contractors. Costs come from LawnStarter, Fixr and This Old House and are national figures. If you spot an error, use the contact page and we will correct it.
Sources
- City of Madison: Prevent Basement Flooding
- Pro Builder: Proper Backfilling and Grading for a Dry Foundation (March 2017)
- LawnStarter: How Much Does a French Drain Cost? (updated October 2026)
- Fixr: Basement Waterproofing Cost (updated February 2026)
- This Old House: Basement Waterproofing Cost (updated March 2026)
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