# Underground downspout drainage in Plano, TX > Underground downspout drainage in Plano, TX: we carry roof water in buried solid pipe past the beds and slab to a pop-up emitter or the curb. Get an estimate. URL: https://clayplanodrainagecompany.com/downspout-drainage/ Buried solid pipe that takes roof water from each downspout past the beds and the slab to a pop-up emitter, an existing line or a permitted curb outlet. Last Updated: November 11, 2026 - **Catch:** downspouts, low spots, side swales - **Carry:** solid pipe at a steady fall - **Release:** to the street, never the neighbor ## Water pooling where the downspouts let out? A downspout gathers rain from a big slice of roof and drops all of it in one place, usually right beside the foundation. A buried line carries it away before it can soak the soil along the slab or pool in the beds. [Clay Plano Drainage Company](https://clayplanodrainagecompany.com/) installs underground downspout drainage in Plano and nearby cities. We route each line in solid pipe to a place your lot can legally release water, which in Plano means toward the street. ## What happens on the first visit We follow each downspout from the gutter to wherever its water ends up today. A short video during a heavy rain shows which ones overflow and where the water runs. - **Roof area.** How much roof feeds each downspout. A corner that drains two roof planes carries far more than a single run of gutter. - **Where it goes now.** Splash blocks, flexible extensions, an old buried line, or a pipe that simply ends in the lawn. - **Old lines.** If a line is already buried, we run a hose into it to see whether it still flows. - **Route and crossings.** Walks, the driveway, beds and the AC pad between the downspout and the outlet. - **The outlet.** Room and fall for a pop-up emitter, or a curb outlet the city permits. The written estimate lists every line with its length, outlet and restoration. ## How much water one downspout carries More than most people expect. Every inch of rain on 1,000 square feet of roof sheds about 620 gallons, and the downspout delivers it in the time the storm lasts. The Richardson weather station, next to south Plano, records about 14 days a year with an inch of rain or more. On each of those days, a splash block puts that whole load within a few feet of the beam. - **At the slab.** Clay beside the foundation swells as it wets and shrinks as it dries, and one corner soaked over and over wets unevenly. - **In the beds.** Water poured on one spot cuts a channel and washes mulch onto the lawn. - **On paving.** A patio or walk beside the house adds its own runoff to the same corner. Keeping water off the slab is the whole point of [foundation drainage](https://clayplanodrainagecompany.com/foundation-drainage/), and downspout lines are usually its first step. ## Solid pipe, not perforated Roof water belongs in solid pipe from the downspout to the outlet. Perforated pipe leaks it into the soil along the way, and that soil is usually the strip beside the house you’re trying to keep dry. Where a line ends matters too. A downspout emptied into a French drain’s stone fills the trench with roof water before it can collect the soil water it was built for. We run downspout lines on their own and join them to a [French drain](https://clayplanodrainagecompany.com/french-drain-installation/) outlet only through solid fittings. ### That black pipe that ends in the lawn An older downspout line is sometimes corrugated pipe run a few yards out and left open or capped in the grass. The soggy spot at its end is where the line lets go of everything it carries. We replace it with solid pipe, or extend it to a real outlet if the old pipe is sound. An old corrugated line that ends in the lawn, leaving its water in one soggy patch. ## Where the water leaves Each line needs an exit that lets water go without sending it to the neighbor. We choose one of three, depending on the lawn and the street. - **Pop-up emitter.** A lid at the end of the line lifts when water pushes up and drops closed afterward. It needs open lawn toward the street and a little fall. - **Existing line.** An older drain that already reaches the street, after we run water through it to prove it works. - **Curb outlet.** A pipe through the curb into the street gutter. In Plano, work in the right-of-way needs the city’s Engineering Permit. In Prosper, the town allows one curb core per lot, no more than 3 inches across. Richardson’s own guidance asks residents to let roof water cross grass or gravel before it leaves the lot, and an emitter in open lawn does exactly that. The guide to [where yard drain water can go](https://clayplanodrainagecompany.com/guide/where-can-yard-drain-water-go/) covers the outlet rules. ## How we install a downspout line The work is short, but the order still matters, because a line that loses fall in one spot holds water there. 1. **Locates.** Texas811 marks buried lines, and we mark each route in white. 2. **Trench.** A narrow trench, sod cut in strips and set aside, soil on tarps. 3. **Adapter.** At the base of the downspout, with a cleanout or removable section so gutter grit can be cleared at the top of the line, not dug out later. 4. **Pipe.** Solid pipe at a steady fall, with sweep fittings at the turns. 5. **Crossings.** A bore under the walk or driveway where the soil allows, or a narrow saw-cut and concrete patch where it doesn’t. 6. **Test.** We run a hose into the gutter and watch the outlet open. 7. **Restore.** Sod goes back, sprinkler lines get repaired and we walk you through the route. ## What a downspout line costs Our typical range for an underground downspout line is $300 to $800 per downspout. That’s one downspout with its adapter and roughly 10 to 30 feet of buried solid pipe to an emitter, a curb outlet or a working line; the estimate sets your figure. Longer runs, crossings under walks or the driveway, rock in the trench and a curb outlet push a line toward the top. Doing several downspouts on one visit spreads the setup across them. The [downspout drainage cost guide](https://clayplanodrainagecompany.com/guide/downspout-drainage-cost-plano/) has the detail. - Where downspouts drop into a narrow [side yard](https://clayplanodrainagecompany.com/side-yard-drainage/), we price the lines with the side-yard fix. - Where they feed a [catch basin](https://clayplanodrainagecompany.com/catch-basins/) or a [whole-yard system](https://clayplanodrainagecompany.com/yard-drainage/), they become branches of one route. ## Keeping downspout lines clear Most downspout lines clog from the top. Roof grit, seed pods and leaves wash straight down out of the gutters. Keep the gutters clean, check that the emitter lid lifts freely, and flush from the cleanout if water backs up at the downspout. A line that still won’t drain after flushing is a job for [drain repair and cleaning](https://clayplanodrainagecompany.com/drainage-repair/). If the pooling continues somewhere else in the yard, the [standing water](https://clayplanodrainagecompany.com/standing-water-in-yard/) page explains how we trace it. ## What's included - A site visit that traces each downspout, the roof it drains and where its water goes now - A written estimate listing each line, its run length, the outlet and restoration - Texas811 locates, with each route marked in white - A downspout adapter at the base, with a cleanout or removable section for clearing gutter debris - Buried solid pipe at steady fall, with sweep fittings at the turns - A pop-up emitter in open lawn, a tie-in to a working line, or a permitted curb outlet - A bore or narrow saw-cut under walks and driveways where a line has to cross - Water run from the gutter to the outlet before backfill - Sod set back and crossed sprinkler lines repaired ## Splash block, pop-up emitter or curb outlet? | | Splash block or short extension | Buried line to a pop-up emitter | Buried line to the curb | | --- | --- | --- | --- | | Where the water lands | A few feet from the wall | In open lawn, well clear of the slab | In the street gutter | | Fits when | The ground falls away steeply and nothing sits downhill | The front or side lawn has room and some fall | The lawn is too flat or too small for an emitter | | Watch for | Erosion and a soaked strip beside the beam | Clippings and soil holding the lid shut | The city permit for work in the right-of-way | | In a big storm | Water spreads back toward the house | The lawn around the emitter stays wet for a while | It can back up while the gutter runs full | ## Related resources - [Cost Guide**How much does underground downspout drainage cost?** What it costs to bury a downspout line in Plano clay, what the price covers from the adapter to the outlet, and how several downspouts add up.](https://clayplanodrainagecompany.com/guide/downspout-drainage-cost-plano/) ## How we run a job ### Call You tell us what you see, where it pools and when. ### Look We walk the yard, measure the fall and find a legal outlet. ### Mark We call Texas811 for locates and paint our route in white. ### Build We trench to grade and set stone, fabric, pipe and outlet. ### Test We run water through the system before any backfill. ### Restore We put back sod and beds and repair crossed sprinkler lines. ## What this work looks like Downspout adapter at the base of a brick wall feeding a solid pipe, with a removable cleanout section Narrow trench across a side lawn with a solid drain pipe laid in it, sod strips stacked beside Pop-up emitter lid lifted open in a front lawn, releasing roof water onto the grass Small hole dug beside a concrete front walk, a green drain pipe pushed through under the slab edge ## Downspout drainage: questions ### Should downspouts drain into perforated or solid pipe? Solid pipe, the whole way. Perforated pipe leaks roof water into the soil along its route, and on most lots that route runs right beside the house. Solid pipe delivers all of it to the outlet, where it can leave the lot. ### How deep does a downspout line get buried? Deep enough to stay clear of edgers, aerators and sprinkler work, and deep enough to keep a steady fall over the whole run. On a long run across a flat yard, the far end sits deeper than the start. The estimate shows the route, and the depth follows the fall. ### Can several downspouts share one line? Yes, when the shared line is sized for all of them at once and each downspout joins it through its own fitting. Two corners on the same side of the house often share a run to one outlet. A corner that drains a large roof area may need its own line. ### My neighbor says my downspouts flood their yard. What do I have to change? Texas Water Code section 11.086 bars diverting surface water in a way that damages another property, and Plano doesn't permit lot-to-lot drainage. The usual fix is to carry those downspouts in buried pipe to an outlet on your own lot that drains toward the street. ### Do you work on the gutters too? No. Gutters and gutter guards are separate work. We start at the bottom of the downspout and handle everything from there to the outlet. If a gutter overflows before water reaches the downspout, a buried line can't help with that part. ## Related services - [Service**Catch basins** A grated box set at the lowest point of a lawn, bed edge or patio that takes in surface water and sends it through solid pipe to an outlet.](https://clayplanodrainagecompany.com/catch-basins/) - [Service**Foundation drainage** Drainage work that keeps water from collecting against your slab: downspout lines, perimeter drains and grade along the beam. Not structural foundation repair.](https://clayplanodrainagecompany.com/foundation-drainage/) - [Service**Side yard drainage** Restoring or replacing the shallow swale between two houses so water from the back yard reaches the street instead of pooling along the fence and the slab.](https://clayplanodrainagecompany.com/side-yard-drainage/) ## Get an estimate for downspout drainage Tell us where the water stands and when. We walk the yard, measure the fall and send a written estimate.