What is drainage?

What this means for your home project

1. Look at the ground beside the foundation and identify whether surface water flows away from the house. Source: Northern Virginia Soil and Water Conservation District, read 2026-11-06.
2. Request the footing construction drawings from the builder or local building inspection files to locate the original drainage details. Source: Northern Virginia Soil and Water Conservation District, read 2026-11-06.
3. Ask for a written drainage scope identifying the swale or drain route and its downstream outlet, such as a drywell or stormwater sewer. Source: Pacific Northwest National Laboratory, read 2026-11-06.
4. For a tight setback, ask the scope to identify the swale or drain that will carry water away where less than 10 feet is available. Source: Pacific Northwest National Laboratory, read 2026-11-06.

Why is my yard wet?

Wet yard drainage can reflect blocked flow paths or soil conditions. NVSWCD (read 2026-11-06) describes lawns still soggy "two or three days following a rain" as potentially having blocked or settled drainageways. Johnston County also lists soil compaction and high groundwater among possible causes. (source)

“If your yard, or some portion of it, remains wet and soggy for extended periods (two or three days following a rain), the natural drainageways may be blocked or have settled and do not have enough grade to drain.” (source) “These may include the amount and frequency of rain fall, naturally high water tables, soil type, proximity to wetlands or waterbodies, location in relation to a flood plain, improper grading, soil compaction, poorly maintained drainage swales, removal of trees, etc.” (source)

How can I fix a drainage problem?

Drainage repairs depend on the cause. Johnston County recommends maintaining unobstructed flow paths or regrading. For a basement that still leaks with no drain flow, NVSWCD (read 2026-11-06) says the pipe may be "plugged with earth or tree roots" and may need reopening. (source)

“This really depends on the cause of the drainage issue, but the best solution for most solvable issues is to ensure drainage swales, downspouts, culverts, and storm drain inlets are free of obstructions and properly maintained or to regrade the problematic area.” (source) “If the drain is there, but there is no flow and your basement continues to leak, the pipe may have become plugged with earth or tree roots over time.” (source) “It may require snaking-type equipment to reopen plugged drains along all or part of the length of the footing.” (source)

Who is responsible for maintaining drainage easements?

Drainage easement maintenance has a local scope: Johnston County (read 2026-11-06), North Carolina, assigns owners the recorded easement portion on their property. Its example divides a "20' drainage easement" along a property line into each owner’s 10-foot portion. That example describes Johnston County’s guidance. (source)

“Individual property owners are responsible for the maintenance of any portion of a recorded drainage easement that is located on their property.” (source) “For example, if a 20' drainage easement is located straight down a property line, each property owner is responsible for the 10' of the easement that is on his or her property.” (source)

How can I identify a drainage ditch?

A yard drainage ditch or swale can carry surface water toward the front or rear of a lot. NVSWCD (read 2026-11-06) describes a swale "between houses along the property line" and contrasts that surface route with a catch basin connected to a pipe below ground. (source)

“Most yards are originally graded so that water flows from the front to the street and from the back to a swale, ditch, or storm sewer.” (source) “A swale is also normally provided between houses along the property line to the front or rear or both.” (source) “You can also drain surface water from your backyard with a catch basin placed at a low spot.” (source) “It is connected to a subsurface pipe that carries the runoff to a waterway or a storm sewer.” (source)

How much slope is needed for proper yard drainage?

For paved surfaces, PNNL (read 2026-11-06)’s summary of IRC 2009, 2012 and 2015 specifies a "slope of 2% away from the foundation" within 10 feet. Its ENERGY STAR guidance for permeable ground, which lets water soak through, instead calls for at least 0.5 inch per foot over 10 feet. (source)

“The 2009, 2012, and 2015 International Residential Code require impervious surfaces within 10 feet of the building’s foundation to have a slope of 2% away from the foundation.” (source) “ENERGY STAR Single-Family New Homes requires permeable surfaces sloped ≥ 0.5 inch per foot away from the home for ≥ 10 feet.” (source)

What factors affect the cost of yard drainage systems?

Drainage work can become harder after construction. PNNL (read 2026-11-06) describes regrading after concrete driveways and patios are poured as a "difficult and expensive process" when slopes send water toward the home. Existing paving and the need to reshape that slope are scope factors to discuss in a drainage bid. (source)

“Once a home has been constructed and concrete driveways and patios are poured, it is a difficult and expensive process to regrade the site should water issues arise due to negative slope on one or more sides of the home.” (source)

Sources

• Soils and Drainage — You and Your Land — Northern Virginia Soil and Water Conservation District; read 2026-11-06.
• Stormwater, Erosion, and Riparian Buffer Program — FAQs — Johnston County, North Carolina, Public Utilities; read 2026-11-06.
• Final Grade Slopes Away from Foundation — Building America Solution Center — Pacific Northwest National Laboratory; read 2026-11-06.