Football drainage: it’s what’s inside that counts

By Mary Helen Sprecher

When a football field needs improvement and there’s money to sink into it, it’s likely that the owner is going to be faced with the choice of how this money gets used.

Deciding between one improvement and another isn’t easy at all. After all, some improvements are highly visible and make a field look like a showpiece. An improved entryway, a new scoreboard, upgraded lighting, Wi-Fi throughout, a press box—those are some great examples of physical improvements that add a lot to a football stadium’s aesthetic. They’re additionally valuable because they allow for recognition of sponsors, donors, alumni and other benefactors, and they look good when sportswriters see them.

But on the other end of the scale is what can be classified as largely invisible investments. They add to the playing experience, make the field work better overall but they’re just not sexy. Examples might include new irrigation equipment, better fencing and better storage buildings for maintenance equipment.

Most people would agree that it’s not as easy to put a donor’s name on a storage shed as it is to put it on a scoreboard. And let’s face it; those kinds of improvements are right up there on the excitement scale with household insulation and basement waterproofing. They’re not glamorous, but they are totally necessary.

At the top of the list of what really makes a field great (and isn’t the least attractive as an expenditure) is this: drainage. After all, even the best Wi-Fi and the coolest scoreboard won’t count for much if the field can’t be used because it’s a muddy mess. The usefulness of the field and its long-term performance, as well as the satisfaction of athletes and ultimately of the field owner, is all tied to having an effective drainage system.

Beneath the surface

Grass fields are some of the most popular, best loved facilities nationwide. But not all fields are equal. And looking at it from the surface, the average person may not be able to see what causes one field to drain well and another to be wet and unusable. That’s because in most cases, the secret is actually underneath the grass, in the soil. Here’s a quick synopsis (which, by the way, is not meant to replace the knowledge or input of a knowledgeable professional.)

There are two basic types of natural grass fields: native soil and sand-based. A native soil field may be a true native field, in which only the soil found at the site is present, or a modified native soil field, or a sand-cap field.

A sand-based system, meanwhile, is one in which the native soil is completely removed, and replaced with an under-drain system and a drainage media layer (principally stone and rootzone material that is largely sand) to improve drainage.

None of these fields is “better,” per se; however, one may be better than another in any situation. According to the book, Sports Fields: A Construction and Maintenance Manual, “The main problem with native soil fields is drainage. Most native soils absorb water quite slowly and cannot handle large amounts; therefore, without additional provision for drainage, these fields can easily become muddy, worn and/or unusable.”

So the question becomes this: do you have good drainage, or does it need some help? If you would like to see your field drain a bit better, ask the right people for advice. A knowledgeable professional can help you examine your options and decide, for example, whether you should consider amending the soil in the field. Depending upon your budget, your priorities, your weather conditions and your usage, this may (or may not) be the best option.

Amending your soil can be looked at as an investment; while it might not be the aesthetic improvement you’ve dreamed of (as would be the case with lights, scoreboards and so forth), it can pay dividends down the road in making the field drain better and thus, be playable sooner after a rain. However, it is only one part of the drainage equation.

The amount of slope your field has will also play into how well it sheds water. Fields may be crowned in the center (so that water runs to both sides) or they may be tilted to one side. Different governing bodies, such as the NCAA or the NFHS, will require varying degrees of slope for each sport. The most current version of the rules for the correct governing body should always be available.

This next tip may sound self-evident, but it’s often forgotten: The only water that gets onto the field (no matter what type of field) should be either rainwater or planned irrigation. In other words, water that comes off the bleachers or the dugout roof, drips down hillsides or comes off any other structure or slope should be intercepted and collected by perimeter drainage before it gets the chance to hit the field.

Types of drainage

It’s time to venture into a brief description of various drainage systems. The following are some popular options; however, any facility owner is advised to consult with a field builder or manager who can help evaluate the site conditions and make recommendations.

A subsurface drainage system, which takes its name from its positioning, meaning it manages water that makes its way underground) can help fields dry more quickly.

The traditional type of drainage system for a sports field has been the pipe drain which uses perforated pipe placed in the subgrade. These pipes are laid in trenches, surrounded by coarse sand or clean stone to within 4 inches of the surface of the subgrade and capped with sand. Water then drains downward through the rootzone and stops in the trench where it enters the pipe from the bottom. Drains are typically placed 3 to 10 feet apart for native soil, and 10 to 30 feet apart for sand-based fields. They are surrounded by clean stone or coarse sand.

Another type of system exists: flat drains, sometimes called strip drains, 6 to 18 inches wide and 1 to 2 inches thick, without a wrapping of filter fabric, which are placed horizontally on the subgrade during construction. They also may be trenched in and placed vertically after installation of the rootzone in either native or sand-cap fields.

In addition, say builders, there’s the least expensive (and still highly effective) sand vein system, sometimes called a sand silt system. This in particular works well in a native soil field.

The type of drainage chosen and all, or any combination of the factors listed above, including soil modification, slope and drainage installation may be considered, will depend on a variety of factors; these include:

  • Owner budget
  • Weather conditions
  • Existing slope
  • The type of soil
  • Local regulations
  • Amount of use the field receives (and whether there are other facilities that can handle games if the field needs to be rested after a heavy rain, for example)

It’s easy to spend money on visible improvements. What’s oftentimes more important, though, is knowing that even the best flagship facility isn’t going to play well if it doesn’t drain correctly. It’s an investment, rather than an expenditure, and it will pay you back for years to come.

Mary Helen Sprecher is a freelance writer associated with the American Sports Builders Association, which sponsors meetings and publishes newsletters, books and technical construction guidelines for athletic facilities. 866-501-2722 or www.sportsbuilders.org