# Is it a floodplain or a yard drainage problem? > Is the water in your yard rain collecting on the lot, or a creek rising? How to tell, how to check FEMA flood maps, and what a yard drain cannot do for you. URL: https://reinirvingdrainagecompany.com/guide/floodplain-or-drainage-problem/ Guide The same muddy back yard can have two very different causes. One can be fixed on the lot. The other belongs to the creek, the city and, often, a flood policy. ## Key takeaways - Rain that lands on your lot and collects is a drainage problem; water that rises out of a creek or channel is a floodplain problem. - FEMA flood maps, and the FEMA flood-zone layer on the county appraisal district map, show whether a lot sits in the 1% annual chance floodplain. - A yard drain needs a lower outlet. When the creek is high, the outlet is under water and the drain cannot help. - In Dallas, the Floodplain Management section (214-671-2219) makes site visits for flooding, drainage and erosion problems. Watch where the water comes from. If rain falls on your lot and its neighbors and collects in a low spot, it is a drainage problem that grading, basins or drains can fix. If water rises out of a creek, channel or the Trinity and spreads across the yard, it is a floodplain problem that no yard drain can stop. [Rein Irving Drainage Company](https://reinirvingdrainagecompany.com/) works on the first kind. ## The clearest test: which way the water moves | Clue | Points to a lot drainage problem | Points to a floodplain problem | | --- | --- | --- | | Where water enters | From the roof, the lawn, a neighbor’s lot or the street | From the direction of a creek, channel or river | | When it peaks | During or just after the heaviest rain | Hours later, as the channel rises from rain upstream | | How it leaves | Sits in a low spot and soaks in slowly | Recedes as the channel drops, often all at once | | What it leaves behind | Puddles, soft ground, bare patches | A debris line, silt or trash carried in from the channel | | Who else is affected | Mostly your lot, maybe one neighbor | A whole row of houses along the same creek | Photos and the time of each one, taken during a storm, settle most cases. A video showing water flowing in from the creek side is better than any description. ## How to check flood maps FEMA publishes Flood Insurance Rate Maps showing the regulatory floodplain, including the 1% annual chance floodplain. You can look an address up on FEMA’s Flood Map Service Center. In Dallas County, the appraisal district map also has a FEMA flood-zone layer, which is often the quicker way to see a specific lot. Dallas’s own zoning map shows it too. Two cautions. A map line is not a wall: lots just outside it can still flood, and older maps can miss newer development upstream. And a lot partly inside the line is treated as in it for any earthwork on that part. ## What the ground tells you Low ground near creeks has its own soils. The USDA soil survey maps Ovan clay, frequently flooded, at a north Irving sample point, and Frio silty clay, frequently flooded, at a south Irving point and in north Grand Prairie. “Frequently flooded” is the survey’s own flood class for those soils. These are sample points, not every lot, but if a yard sits on that kind of ground, two things follow: water drains slowly through the clay, and any outlet nearby may sit higher than the yard when the creek is up. ## What a yard drain cannot do Every gravity drain depends on a lower outlet. When a creek or the storm system is full, that outlet is under water and the drain backs up. A [sump pump](https://reinirvingdrainagecompany.com/sump-pump-drainage/) can lift rain that collects on a lot to a higher outlet, but it cannot pump down a rising creek. Raising the yard with fill is not a simple fix either: in a mapped floodplain, fill can push water onto others, and cities review it. In Dallas, earthwork within the 1% annual chance floodplain is reviewed before construction is permitted. What drainage can still do on a floodplain lot: - Handle the rain that falls on the lot itself, so it does not add to the problem. - Keep [roof water](https://reinirvingdrainagecompany.com/downspout-drainage/) away from the house between flood events. - Use drains that do not change ground levels, such as a flush [catch basin](https://reinirvingdrainagecompany.com/catch-basins/), where the outlet is allowed. ## Who handles creek and channel problems Creeks and major channels are public drainage, and cities manage them. - **Dallas.** The Floodplain Management section, at 214-671-2219, makes site visits for flooding, drainage and erosion problems. - **Irving.** The city is carrying out a West Irving Creek channel project, funded in part by a drainage utility rate increase and a Texas Water Development Board grant. It has also built public fixes elsewhere, including a subdrain on Wingren Drive in Las Colinas for groundwater (2022) and a 900-foot flume on Campus Circle. For a specific Irving address, we confirm the rule per address, and the city’s drainage staff are the people to ask about a creek. - **Other cities.** Each has its own stormwater or engineering office; the [drainage permits guide](https://reinirvingdrainagecompany.com/guide/drainage-permits-irving-dallas/) lists rules for the nearby cities. ## When it is both Many creekside lots have both problems: they flood from the channel a few times in a decade and stay soggy after every ordinary rain. The ordinary wetness is usually a [yard drainage](https://reinirvingdrainagecompany.com/yard-drainage/) job. The flooding is a matter for flood insurance and the city. The [insurance guide](https://reinirvingdrainagecompany.com/guide/does-insurance-cover-yard-flooding/) explains why the two are treated so differently. ## A practical next step Look the lot up on the FEMA map, then take photos during the next storm showing where water enters. If it comes from the lot, the roof or the street, the [step-by-step guide](https://reinirvingdrainagecompany.com/guide/how-to-fix-yard-drainage-problems/) explains the fix, or [send the photos to us](https://reinirvingdrainagecompany.com/contact/). ## Questions people ask ### What does the 1% annual chance floodplain mean? It is the area FEMA maps as having a 1 in 100 chance of flooding in any given year, often called the 100-year floodplain. Over a 30-year mortgage, that adds up to a meaningful chance of at least one flood. ### Can I fill my yard to get it out of the floodplain? Not without approval. Fill in a mapped floodplain can push water onto other properties, so cities review it. In Dallas, earthwork within the 1% annual chance floodplain is reviewed before construction is permitted. ### Why does my yard drain back up when the creek is high? Because its outlet is lower than the water in the creek or storm system. Water cannot flow downhill into a channel that is already full, so it backs up the pipe until the creek drops. ## Get an estimate Tell us where the water stands and send a photo. After a site visit, you get a written price. [(469) 680-8773](tel:+14696808773) ## Related service [Yard drainage systems](https://reinirvingdrainagecompany.com/yard-drainage/) ## Related services - [Yard drainage systems](https://reinirvingdrainagecompany.com/yard-drainage/) - [Sump pump drainage](https://reinirvingdrainagecompany.com/sump-pump-drainage/) - [Standing water in the yard](https://reinirvingdrainagecompany.com/standing-water-in-yard/) ## Guides - [Insurance and yard flooding](https://reinirvingdrainagecompany.com/guide/does-insurance-cover-yard-flooding/) - [Drainage permits in Irving and Dallas](https://reinirvingdrainagecompany.com/guide/drainage-permits-irving-dallas/) - [How to fix yard drainage problems](https://reinirvingdrainagecompany.com/guide/how-to-fix-yard-drainage-problems/) - [Street water flooding a driveway](https://reinirvingdrainagecompany.com/guide/street-water-flooding-driveway/) ## Not sure where your water comes from? Send a photo during the storm and tell us how close the nearest creek or channel is.