Inadequate landscape drainage commonly leads to water pooling, soil erosion, and foundation damage. When water saturates the soil near a home, it can cause basement leaks or cracks in the foundation. Addressing these issues promptly is important because persistent standing water destabilizes the ground, damages plant life, and attracts unwanted pests. Effective drainage solutions protect both the landscape’s health and the structural integrity of the building.
Identifying the Source of Water Issues
The first step in correcting a drainage problem is understanding precisely where and why water is accumulating. Observing the yard during and immediately after a heavy rain shower is the most effective diagnostic method. This allows you to trace the exact path of water runoff and identify the low spots where pooling occurs.
A primary concern is the grading, or slope, of the ground immediately surrounding the foundation. Ideally, the soil should slope away from the home by at least six inches over the first ten feet to ensure water flows away from the structure. If the land slopes toward the house, water will press against the foundation walls, increasing the risk of seepage and damage.
You should also look for signs of soil compaction, which significantly reduces the soil’s ability to absorb water. Compaction causes water to pool on the surface or run off instead of infiltrating the ground. A simple test is to dig a hole about a foot deep, fill it with water, let it drain, and then refill it; if the second filling drains less than an inch or two per hour, the soil is likely compacted.
Simple Surface Solutions for Water Control
Many drainage problems can be resolved with non-invasive surface alterations that redirect water flow. Re-grading the area immediately around the home is often the most impactful solution, aiming to maintain the required slope away from the foundation. This involves adding or moving soil to achieve a gentle, consistent decline of at least one inch of drop for every ten feet of horizontal distance.
Creating a swale, a broad, shallow ditch, can effectively guide sheet flow runoff away from critical areas. Swales are typically grass-lined to prevent erosion and blend into the landscape while moving excess surface water to a safer discharge point. Conversely, a berm, a raised mound of soil, can be constructed to intercept and divert water flow before it reaches a sensitive area, such as the home’s foundation.
Managing roof runoff is another important surface correction. Downspouts should be extended so that the water they collect is released at least six feet away from the foundation. Splash blocks, simple pieces of concrete or plastic, help disperse the water’s force, preventing runoff from eroding the soil at the base of the house.
Dry Wells
For localized, minor pooling, a small dry well can be installed. This involves digging a shallow pit, lining it with filter fabric, and filling it with gravel to temporarily store and slowly release water into the surrounding soil.
Installing Underground Drainage Systems
For larger volumes of water or persistent subsurface issues, installing an underground drainage system becomes necessary. The French drain is a common solution, designed to collect both surface water and shallow groundwater before it reaches a foundation or saturated area. This system consists of a trench lined with geotextile fabric, a layer of coarse gravel, and a perforated pipe placed inside the trench.
The perforated pipe is laid with its holes facing down to collect water that filters through the gravel and fabric. The entire system must be installed with a consistent downhill slope, generally one inch of drop for every eight to ten feet of length, to ensure gravity pulls the water toward the discharge point. The filter fabric is then wrapped completely around the gravel and pipe to prevent fine soil particles and roots from entering and clogging the system.
Catch Basins and Trench Drains
In areas with hard, non-permeable surfaces like driveways or patios, specialized components are needed to capture runoff. Catch basins are containers with grates placed at low points to intercept concentrated surface flow. Trench drains are long, narrow channels with removable grates that collect water across a broader path. Both are connected to solid, non-perforated drain pipes that carry the collected water to a safe discharge location away from the property.
Discharge Options
The final element of any underground system is the discharge, which must be routed to an appropriate area to avoid transferring the problem elsewhere. Options include directing the water to a street curb, a storm sewer system (which often requires local permits), or a large, deep dry well designed to handle the system’s output. Alternatively, water can be discharged through daylighting, where the pipe emerges from the ground at a lower elevation to release water onto a stable, sloped area of the yard.