Replacing a Grass Sports Field with Synthetic Turf

Last Updated on October 19, 2026 by UDC Sports

In a single week, a stadium or sports field might host Friday night football, weeknight soccer, marching band rehearsals, and a full schedule of PE classes. On natural grass, all of that use starts to show up as thin spots between the hashes, and a heavy storm can leave the end zones soft for days afterward. Converting a grass field to artificial turf can allow it to handle a lot more hours of use, as well as let it reopen much sooner after the rain stops.

From the bleachers, the completed project might look like one green surface swapped for another. Most of the work happens below grade, since natural grass and turf installations move water in very different ways. At many American schools the athletic field also sits inside a running track, and as our guide to track and field construction explains, the track and the field can share a subgrade and a drainage system, so a new turf field typically has to be designed around the running track that’s already there.

How Grass & Turf Sports Fields Drain

A natural grass football field is often “crowned,” which means it’s built a little higher along its center and slopes gently down toward each sideline. When it rains, water runs across the surface and off the sides of the field, while the soil soaks up what it can. For reference, the soccer field diagram published by the National Federation of State High School Associations (NFHS) calls for at least a 1.5% slope, measured from center to side, on a natural grass field that relies on surface drainage.¹

A synthetic field, on the other hand, drains downward. Water passes through small openings in the turf backing, filters into a layer of crushed stone, and then flows out through perforated pipes beneath the stone.

Since the base is doing most of the work, the surface itself can be built much flatter. In fact, the same NFHS diagram sets the minimum slope for a synthetic field with subsurface drainage at just 0.5%.¹

Feature	Natural Grass Field	Synthetic Turf Field
Main drainage path	Across the surface toward the sidelines	Down through the turf and into the stone base
Surface shape	Crowned, with a steeper slope from center to side	Flatter, with a shallow crown or a single plane
Below the surface	Topsoil or a sand-based rootzone over native soil	Compacted crushed stone over graded, compacted soil
Subsurface pipe	Present on some fields	A pipe network beneath the base
Routine care	Mowing, irrigation, fertilizing, and rest periods	Grooming, infill top-ups, and periodic testing

As the table above shows, converting a stadium field changes just about the whole profile. The crown comes down, the subgrade gets reshaped, and a subsurface drainage system goes in where the grass field may have had little or none. And all of that happens inside a fixed footprint, since the track around the field stays right where it is.

Converting a Sports Field from Grass to Artificial Turf

Planning usually starts with a good record of what’s on the site today. For example, a topographic survey captures the field’s existing grades, along with the elevations of the track’s inside edge, which the new field will need to meet.

Soil testing can help show how the native ground will hold up under a stone base. Utility locating then finds the irrigation lines, conduit, and any older drain pipe running beneath the grass.

From there, the design works out the details of the new field. That includes which sports get permanent inlaid lines, whether the system will have a shock pad (a cushioning layer between the stone and the turf), what type of infill goes in, and which existing features can stay, like goalposts, fencing, and lighting.

How Much of the Infield to Turf?

The playing field itself is the first piece, but the infield inside a track also includes the strips along each sideline, and the curved D-zones past each end zone.

A school can choose to carry the synthetic surface all the way out to the track’s inside edge, or it can turf the field and keep grass in some of the areas around it.

Turfing all the way to the track gets rid of those narrow bands of grass along the curb that still need mowing and watering, and it gives teams one consistent surface across the sideline areas. Keeping grass in the D-zones reduces the synthetic area. Those zones stay on the maintenance schedule, though, and the irrigation lines have to be rerouted around the new field. If any field event areas sit in the D-zones, their surfaces get planned right alongside the turf layout.

Stormwater Review

Changing a field’s surface can bring a stormwater review along with it. Agencies don’t all classify synthetic turf the same way. It can vary from one state to the next, and sometimes between a city and the county right next door. In some areas, a turf field may be considered an impervious area, in the same category as pavement. In other areas, they may give credit for all the water the stone base can store or let soak into the ground below, which can reduce the separate stormwater measures a site needs.² The stone has a good bit of open space between the rocks, so it can hold rainwater and let it out slowly to the drains.

Either way, the classification can affect the permit timeline and whether the project needs to add detention or treatment features. A detention feature is a spot to hold runoff for a while, like a pond or an underground tank, while treatment features clean the water before it leaves the property.

Protecting the Track During Construction

Every load of stone, every truck hauling soil away, and every piece of grading equipment has to get across the track to reach the field inside it.

That’s a lot of heavy traffic over a surface built for humans to run on, and loaded trucks and turning equipment can damage it. So the construction plan lays out how the oval will be protected for the length of the project, which may include steps like:

• One designated crossing point, with the fence opened up at that spot and all construction traffic routed through it
• Heavy-duty crossing mats, or layered plywood over protective sheeting, anywhere vehicles cross the lanes
• Protective covers on the inside lanes where crews are working along the edge of the field
• Regular sweeping at the crossing to keep mud and stone off the running surface

Typical Steps for Replacing Grass with Artificial Turf in a Sports Field

For the most part, a conversion follows the same order as new turf field construction, with removal and regrading added at the front end. Field work is often scheduled for the offseason so the new surface is ready by the time fall practice starts. Weather, permitting, and material deliveries can all affect how the phases line up on any given site.

Here’s a look at the phases in the order they might typically happen. Of course on some projects the steps can overlap somewhat, with drainage and curb work running at the same time on different parts of the field, just for example. The exact methods may also vary with the turf system and the design.

Where the Field Meets the Track

A track is sloped so water drains toward its inside lane, which sends runoff from the running surface to the inside edge of the oval. On a crowned grass field, water from the field heads toward that same edge, just from the other direction. After a conversion, the field’s water drains down into the stone base, while the track keeps shedding its water toward the inside edge, the same as before.

That means the drain along the edge, often a trench drain or a perforated line beside the curb, gets evaluated during design. Its condition, capacity, and elevations all help determine whether the new field’s perimeter collector ties into it or runs to the storm system on its own. If you’d like more background, our overview of sports field drainage covers how grading and subsurface systems work together.

The finished heights along that line are all set together. The top of the turf, the perimeter curb, and the track’s edge are designed to meet cleanly, without a lip that could catch a foot or a cleat. The edge detail affects routine upkeep as well, since infill that migrates off the field tends to settle right where the turf meets the curb.

Planning for Future Turf Replacements

The base and drainage built during a conversion are designed to outlast the turf on top of them. That’s helpful down the road. When the surface eventually reaches the end of its service life, the turf and infill come off, the base gets inspected, and a new system can go down on the existing base as long as it’s still in good shape. Old turf can go through sports field removal and recycling, which keeps that material out of landfills.

It’s a good idea to hold on to the as-built records from the conversion, since they can make that future project simpler to plan. Drawings that show final grades, drain pipe locations, sleeve and conduit positions, and the storm system connection give the next design team a clear starting point, without anyone having to dig to find them.

Frequently Asked Questions

Q: Does a grass field need new drainage to become a turf field?

A: Usually, yes. A synthetic field drains through its base, so it relies on a pipe network beneath the stone. Some grass fields already have drain lines, and the site survey will show whether any of them can be reused, but their depth and spacing often differ from what a turf base calls for.

Q: Does a synthetic turf field still have a crown?

A: It can. Some turf fields keep a shallow crown, but at a much lower slope than the grass field had. Others are graded as a single plane that falls gently toward one side. Which approach a site uses depends mostly on the existing grades and where the drainage outlets are.

Q: What happens to the grass and soil removed from the field?

A: That depends on the soil quality and the site plan. It’s either hauled off site or reused for grading somewhere else on the property.

Q: When should a school start planning a conversion?

A: Field construction is usually scheduled for the offseason so the turf is ready in time for fall sports. Surveying, design, stormwater review, funding approval, and public bidding all have to happen before that window opens, so it helps to work backward from the date the field needs to be ready and set the design start from there.