When rainwater runs off roofs, driveways, and yards, where does it actually go? Many homeowners are surprised to learn that managing stormwater properly is one of the most important parts of protecting their property, preventing drainage problems, and preparing for construction projects. Choosing the right stormwater practice controls runoff, reduces erosion, and protects neighboring properties from water damage.
For residential properties, selecting and sizing the right stormwater solution requires you to consider several factors that affect how water flows across the land. This is where experienced civil engineers can make a major difference.
Engineers select residential stormwater practices by evaluating how water moves. Factors such as soil type, slope, surface area, and runoff volume determine the best solution for your property. Common options include rain gardens, dry wells, and infiltration trenches designed to absorb or slow water before it leaves the property.
Why Stormwater Planning Matters for Homeowners
Stormwater management is about more than preventing puddles in the yard. Poor drainage may lead to several issues you may not immediately connect to runoff. These issues include:
- Soil erosion destroying garden beds
- Water damaging your foundation
- Sudden basement or yard flooding after installing a driveway
That is why thoughtful planning helps ensure water is directed, absorbed, or slowed in ways that protect the property long term.
How to Plan for Stormwater
Starting with the Soil
The first step is usually investigating the soil. The soil composition of your property impacts how water flows and absorbs into the land. Based on your site and project, we select locations best suited for testing. From there, an excavator and our soils professional perform a soil probe.
A soil probe is an excavation of the soils to find limiting zones and soil features. Limiting zones include groundwater, bedrock, and redoximorphic features. These limiting zone depths will dictate the type of practice and the depth to the bottom of the practice.
Which Stormwater Practice Fits Your Property?
In residential applications the limiting zones usually lead to one of three practices. A rain garden, an exposed infiltration trench, or a subsurface infiltration bed.
| Your Limiting Zones | Stormwater Practice | How This Practice Helps |
| Shallow zones, setting the infiltration invert close to the surface | Rain Garden | Uses plants and soil to absorb runoff naturally |
| Small areas with deep zones | Subsurface Infiltration Bed | Stores water underground and allows it to slowly infiltrate |
| Areas near patios or pools | Exposed Infiltration Trench | Slows runoff and filters water through stone and soil |
These systems are designed to reduce runoff while allowing water to return to the ground in a controlled way.
Sizing a Stormwater Practice
Once the practice type is selected, we must determine its size. There are three primary contributing factors. They are discharge rate, infiltration volume and water quality volume. These requirements are set by municipal ordinances, and the goal is to reduce flooding, promote groundwater recharge and improve the quality of water leaving the property.
Why do ordinances have to control these things? New construction increases impervious surface. This in turn increases the rate of discharge and decreases infiltration and water quality. To meet local rate requirements, the stormwater facility must impound runoff. Thereby, releasing it at the same or slower rate than before construction.
Next, the basin must capture runoff to offset the extra volume generated. This extra volume occurs because new surfaces absorb less runoff than natural ground. Thus, a facility must infiltrate runoff back into the ground. This usually must occur within seventy-two hours. This infiltration rate comes from a soil percolation test. We perform this test at the invert of the facility, as set by the soil probe.
What Do Homeowners Need to Know?
As the owner of a property, the most important thing to understand is maintenance. No practice is maintenance free, but most practices are not maintenance intensive either. The most important thing to remember is that stormwater systems are not “set it and forget it.”
What Maintenance Does Your Stormwater Practice Need?
- Rain Gardens – Regular landscape care such as weeding, mulching, pruning, and removing debris as needed.
- Exposed Infiltration Trenches – Removing debris and preventing clogging is key. Occasionally remove, clean, and reinstall the stones.
- Subsurface Beds – Similar maintenance to the exposed trench, although you can reduce the amount of maintenance by incorporating filters.
Planning a Stormwater Solution for Your Property
Managing stormwater effectively protects your property and helps prevent long-term drainage issues. Because every property is different, selecting the right stormwater practice often requires professional evaluation.
The engineers at All County & Associates specialize in surveying, civil engineering, and environmental engineering services that help homeowners and property developers understand how water moves across their land and how to manage it properly.
Contact All County & Associates today to evaluate your property and design a stormwater solution that works for your home and landscape.
Residential Stormwater FAQs
What stormwater solution works best for most homes?
There is no single solution that works for every property. Rain gardens, dry wells, and infiltration trenches are commonly used, but the right choice depends on site conditions and runoff volume. Consult a professional about your property’s specific needs.
Can stormwater systems improve yard drainage?
Yes. Stormwater systems help capture and slow water before it spreads across the yard, which can reduce soggy areas, and improve overall drainage.
When should I consult an engineer about stormwater?
It is best to consult an engineer when planning construction projects like pools, patios, additions, and driveways, or when experiencing persistent drainage problems.
To learn more about stormwater management, review our Homeowner’s Stormwater Management Guide.
Who is ACA?
Started in 1992 and located in Chester County, PA ACA has grown to become a full-service civil engineering firm. Today, we merge professional services with practical knowledge for residential and commercial projects. No matter the scale, from installing a fence, to building a structure or developing land, you need permits. Because the approval process includes many permits and agencies, it can be a headache. Working with ACA’s full-service team saves you time, money, and headaches. Every step of the way, we are here to support you and educate you about the process. Here are some of the basic services we provide:
Construction Management | Civil Engineering | Environmental Permitting | Septic System Testing and Design | Land Surveying | Wetland Delineations and Mitigation
Please feel free to browse our website or if working on a project or need help, contact us at (610) 469-3830.
Also, join the conversation on: Facebook | LinkedIn
Share this post:
