The short answer
- Send downspout water at least 4 to 6 feet from the foundation. 10 feet is better on a flat lot.
- Good spots: a lawn that slopes away, a driveway that drains to the street, a rain garden or a rain barrel.
- Never toward the foundation, under a raised house, a neighbor’s lot or a sewer cleanout.
- Many homes do better with 3×4 downspouts than 2×3.
Downspout drainage in New Orleans decides where all that roof water lands. Your gutters catch the rain. However, the downspouts decide whether it ends up in the street or under your house. In a city that sits low and gets heavy storms, that last few feet matters a lot.
This guide explains where downspout water should go on a New Orleans lot. It also covers how far to extend it and what changes on raised and slab homes. Finally, it shows when a fix is a quick job.
Why downspout drainage in New Orleans is different
New Orleans gets more than 60 inches of rain in a typical year. For example, summer thunderstorms can drop an inch or more in a single hour. You can check local rainfall records with the National Weather Service office for New Orleans.
Now do the roof math. One inch of rain on 1,000 square feet of roof makes about 620 gallons of water. As a result, a 2,000-square-foot roof can send over 1,200 gallons to your downspouts in one storm.
On top of that, the ground here makes things harder. Much of the city sits at or below sea level. Also, the soil is soft and clay-heavy, so it drains slowly. That’s why water that pools near a house tends to stay there.
What bad drainage does to a New Orleans home
- Water pools under raised homes and keeps the crawl space damp.
- Soil next to slab foundations swells when wet and shrinks when dry.
- Splashing water rots the bottom of siding, trim and porch posts.
- Standing water near the house invites mosquitoes and termites.
- Flower beds wash out and mulch ends up on the driveway.
Where should downspout water go?
The goal is simple. In short, move the water away from the house and toward a spot that can take it. First, look at where your yard slopes. Next, find where water already flows after a storm. Finally, pick an outlet that follows that path.
Good places for downspout water
- A lawn area that slopes away from the house. Grass soaks up some water and slows the rest.
- The driveway or a paved path. This works well when the paving drains to the street.
- A rain garden or rain barrel. These hold water during the storm and release it slowly.
- An underground pipe to a proper outlet. This is cleaner, but it needs care in a high water table.
Places to avoid
- Right at the foundation or under a raised house.
- Toward a neighbor’s lot, fence line or shared driveway.
- Into a sanitary sewer cleanout. Never tie a downspout into a sewer line.
- Onto steps or walkways, where the constant damp grows slick algae.
Before you connect anything to a street drain or curb, check the rules first. In Orleans Parish, ask the Sewerage & Water Board. In Metairie, Kenner and the rest of Jefferson Parish, ask the parish drainage department.
How far should a downspout extend?
A common rule is at least 4 to 6 feet from the foundation. However, 10 feet is better when your yard has the room. The extra distance matters most on flat lots, and many New Orleans lots are very flat.
For example, a short elbow that drops water 12 inches from the wall does very little. The water soaks in and runs right back toward the house. In contrast, a longer extension or a splash block on a slope moves it past the problem zone.
Simple ways to extend a downspout
- Aluminum extensions. They match the downspout and hold up well in the sun.
- Hinged or flip-up extensions. These lift out of the way when you mow or park.
- Splash blocks. They stop erosion, but they only work if the ground slopes away.
- Buried pipe. It hides the water path, but it needs a clean outlet and a slope.
Raised homes vs slab homes
New Orleans has two main house types, and each one needs a different plan.
Raised homes on piers
Shotguns, camelbacks and raised center-halls are common in Uptown, Mid-City, the Marigny and Bywater. Water that drains under these homes keeps the crawl space wet. As a result, wood sills and floor joists stay damp for days.
On these homes, every downspout should end past the drip line of the house. Also, check that the ground under the house is not lower than the yard. If it is, water will flow under the house no matter where the downspout ends.
Slab homes
Ranch-style slab homes are common in Metairie, Lakeview, Gentilly, New Orleans East and Kenner. Here, the risk is soil movement next to the slab. Wet soil swells and dry soil shrinks. In addition, repeated cycles can stress the slab edge and the driveway joint.
That’s why slab homes need steady drainage. In other words, the water should leave the slab edge on every side, not just the front.
Is your downspout sized right?
Many older homes still have small 2×3 downspouts. A 3×4 downspout has about twice the opening of a 2×3. Because of that, it can keep up much better during a hard summer storm.
In addition, spacing matters. A common rule of thumb is one downspout for every 30 to 40 feet of gutter. Also, long runs that drain to a single corner tend to overflow in the middle.
Signs your downspouts can’t keep up
- Water sheets over the front of the gutter during heavy rain.
- You see stripes or stains on the siding under the gutter.
- The ground has a trench or bare spot under the gutter edge.
- Water gushes out of the downspout seams instead of the bottom.
- The downspout gurgles or backs up after a storm.
Clogs: the most common downspout problem here
Live oaks shed most of their old leaves in late winter and spring. Also, many yards have pines, magnolias and crape myrtles that drop debris all year. As a result, the elbow at the top of the downspout clogs fast.
In fact, a clogged downspout is worse than no downspout. The gutter fills, gets heavy and starts to pull away from the fascia. Next, the water spills over the edge right next to the house.
To check a downspout, run a garden hose into the gutter. Then watch the outlet. If the flow is weak or slow, there is a clog. For regular care, our guide on how often gutters should be cleaned explains the timing. You can also book gutter cleaning with our crew.
Underground downspout drains: worth it?
At first glance, buried drains look clean and keep the yard clear. However, they have trade-offs in New Orleans.
- The water table is high, so a buried pipe may sit in water.
- Silt and roots can clog a pipe, and you can’t see the clog.
- Flat lots make it hard to get enough slope to the outlet.
If you choose a buried drain, add a clean-out at the top. Also, make sure the outlet is lower than the inlet and stays clear. Call 811 before anyone digs, so buried utility lines get marked first.
The City’s NOLA Ready green infrastructure guide also covers rain gardens and rain barrels. These options slow water down instead of pushing it to the street.
When to call a gutter crew
Some fixes are easy weekend jobs. For example, you can add an extension or clear an elbow on a one-story house. Other jobs need a ladder, the right tools and some experience.
Call a pro when:
- The gutter pulls away from the house or sags between hangers.
- Downspouts leak at the seams or come loose from the wall.
- Your home needs more downspouts or bigger ones.
- The fascia behind the gutter feels soft or looks dark.
- The house is two stories or the roof is steep.
Our team handles gutter repair in New Orleans, including downspouts, leaks and sagging runs. Is the system old or too small? In that case, we can also install new gutters in New Orleans with the right downspout plan. Gutters Tech has served New Orleans and Metairie homeowners since 2006.
FAQ: downspout drainage in New Orleans
How far should downspouts drain from the house?
Aim for at least 4 to 6 feet from the foundation. However, 10 feet is better on flat lots, and many New Orleans lots are flat.
Can I connect my downspout to the street drain?
Check first. In Orleans Parish, ask the Sewerage & Water Board. In Jefferson Parish, ask the parish drainage department. Never connect a downspout to a sewer line.
Do raised houses need downspout extensions?
Yes. Water that lands under a raised house keeps the crawl space damp. As a result, wood under the house can stay wet for days.
What size downspout is right for New Orleans rain?
Many homes do better with 3×4 downspouts than 2×3. A 3×4 has about twice the opening, so it handles hard storms better.
How often should I check my downspouts?
Check them after big storms and at least twice a year. Also, check more often in spring, when live oaks drop their leaves.
Are rain barrels a good idea here?
They can help. A rain barrel holds some water during a storm. However, you still need an overflow that sends extra water away from the house.
Not sure where your downspouts should drain? Call (504) 305-0325 for a free estimate.
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