How to Plan an Underground Drainage System for Your Massachusetts Property

Quick Answer

To plan an underground drainage system, first identify where the water comes from and where it collects. Next, survey the property elevations, check soil and groundwater conditions, calculate the expected runoff, and choose a safe outlet. The final system may use catch basins, underground pipes, French drains, trench drains, or dry wells. Local permits and utility locations should also be checked before digging.

Why Is Proper Drainage Important?

Rainwater that cannot soak into the ground becomes stormwater runoff. According to the U.S. Environmental Protection Agency, runoff can collect pollutants such as sediment, oil, chemicals, and debris before flowing into local waterways. Too much uncontrolled runoff can also contribute to flooding and erosion.

A well-planned underground drainage system helps manage water closer to where it falls. It can reduce standing water, protect landscaped areas, limit erosion, and direct runoff away from buildings. Proper design also helps avoid moving the problem onto a neighboring property or public roadway.

Source: U.S. Environmental Protection Agency, Urbanization and Stormwater Runoff

Step 1: Identify the Water Problem

Inspect the property during a rainstorm or shortly afterward. Look for standing water, wet lawn areas, soil erosion, overflowing gutters, and runoff moving toward the building.

Common warning signs include:

• Puddles that remain well after a storm
• Water collecting near a foundation
• Wet areas around patios and walkways
• Erosion along slopes
• Ice forming on driveways during winter
• Water entering a basement or crawl space

The location of the puddle may not be the source of the problem. Water might be coming from a roof, driveway, uphill property, or area of compacted soil. Groundwater and plumbing leaks can cause similar problems too, so it is important to identify the actual source.

Step 2: Survey the Property Elevations

Most drainage systems depend on gravity. Because of this, small differences in elevation can have a major effect on the system.

A topographic survey can identify:

• High and low points
• Building and foundation elevations
• Driveway and roadway elevations
• Existing drainage structures
• Property lines and easements
• Wetlands and nearby water features
• Possible drainage outlets

A pipe may appear to slope correctly but still be too flat to drain. In some cases, the proposed outlet is not low enough for a gravity system. Accurate survey information helps prevent these issues before construction starts.

Step 3: Check the Soil and Groundwater

Soil conditions determine how quickly water can soak into the ground. Sandy and gravelly soils often drain faster than dense or clay-rich soils.

Before installing a dry well or infiltration system, the site may need to be checked for:

• Soil type
• Seasonal high groundwater
• Bedrock
• Existing fill
• Infiltration rate
• Distance from foundations, wells, and septic systems

A dry well will not work properly if the surrounding soil drains too slowly or the groundwater is too high. It could remain full when the next storm arrives.

Step 4: Estimate the Runoff

The system needs enough capacity for the area draining into it. Roofs, driveways, parking areas, and patios produce more runoff than lawns because water cannot easily soak through them.

Drainage calculations usually consider the size of the contributing area, surface type, rainfall intensity, available storage, and allowed discharge rate.

An undersized system may overflow during heavy rain. An oversized system may cost more than necessary. A civil engineer can use site information and local standards to determine suitable pipe and storage sizes.

Step 5: Select a Safe Outlet

Every underground drainage system needs somewhere for the collected water to go. Depending on the property, that outlet might be:

• A dry well or infiltration area
• A landscaped area that can safely receive runoff
• An existing private drainage system
• A municipal storm drain with approval
• Another legally permitted discharge point

Water should not be redirected onto a neighboring property or into the street without authorization. Stormwater should never be connected to a sanitary sewer or septic system.

In North Attleboro and other Massachusetts communities, drainage work may need review from the local engineering, public works, building, or conservation department.

Step 6: Choose the Right Components

The correct system depends on the source of the water and the conditions on the property.

Catch Basins

Catch basins collect surface water at low points. They can also hold some sediment before it enters the drainage pipe.

Solid Drainage Pipe

Solid pipe moves water from one location to another. It is commonly used for roof downspouts and catch basin connections.

Perforated Pipe and French Drains

Perforated pipe allows water to enter through openings along the pipe. In a French drain, the pipe is usually surrounded by washed stone and filter fabric. French drains can collect shallow groundwater, but they are not the right answer for every drainage problem.

Trench Drains

Trench drains collect water across a wider surface. They are often placed near garage doors, patios, and driveway entrances.

Dry Wells

Dry wells store runoff underground and let it soak into the surrounding soil. Soil testing and groundwater information are important before choosing this option.

Cleanouts

Cleanouts provide access to the pipe for inspection and maintenance. Leaving them out can make future repairs much harder.

Step 7: Check Utilities, Boundaries, and Permits

Before excavation, underground utilities must be located through the proper utility notification service. Some private utilities may require a separate locating company.

The drainage layout should also be reviewed for conflicts with:

• Water and sewer services
• Gas and electric lines
• Septic systems
• Irrigation pipes
• Property boundaries
• Drainage and utility easements

Projects near wetlands, streams, floodplains, or public roads may require added permits. Checking early can save time and prevent the system from being redesigned after construction has started.

Step 8: Install and Maintain the System

During installation, the contractor should follow the designed pipe slopes and elevations. Pipes need suitable bedding and backfill so they do not settle or become crushed. Catch basins, outlets, and cleanouts should remain accessible.

After installation, maintenance may include:

• Cleaning gutters and downspouts
• Removing leaves from drain grates
• Checking catch basins for sediment
• Inspecting the outlet for blockage or erosion
• Flushing accessible pipes when needed
• Inspecting the system after major storms

Even a well-designed system can clog when it is not maintained.

When Should You Call a Civil Engineer or Surveyor?

Professional help may be needed when water is affecting a basement or foundation, there is no clear outlet, the property has very little slope, or a dry well is being considered. It is also worth getting help when drainage approaches a property line, connects to public infrastructure, or requires municipal approval.

A professional land surveyor can document property elevations, boundaries, and existing drainage features. A civil engineer can calculate runoff and design a system that fits the site.

Get Help With Your Drainage Project

Risser Engineering provides civil engineering and professional land surveying services in North Attleboro, Massachusetts, and nearby communities. If your property has standing water, erosion, or ongoing runoff problems, Risser Engineering can help evaluate the site and determine what information may be needed for a practical drainage plan.

This article is for general information. Drainage systems should be designed for the actual property conditions and applicable local requirements.