Trip, Slip and Fall Hazard: Hidden Depressions in Grade

Successful landscapes require:

  • Proper grading, drainage and amended soil.
  • An automatic irrigation system achieving 100% head to head coverage.
  • Properly installed, high quality plant material.

Each of these functions may require a specific type component, installed at a specific height or location to reduce the potential of creating a site hazard that may result in an accident.  In commercial applications, landscape plans usually include details and specifications dictating type of product and how it should be installed.

Many common landscape products may be improperly installed including:

  • Pop up heads may be incorrectly set to grade against a sidewalk.
  • Valve or drainage boxes set too high or low relative to finish grade.
  • Shrub head installed on a riser adjacent to concrete improvement.
  • Hidden, obscured depressions in grade due to substandard compaction, settlement and subsidence.

    Drainage box set too low.

Improper product selection or substandard installation practices may appear obvious.  A pop up sprinkler head set above the top of  adjacent concrete sidewalk creates a trip hazard.  A drainage structure set well below the turf grade creates a trip slip and fall hazard.  Selecting and installing a spray head on a rigid riser next to a pedestrian sidewalk is a sub-standard industry practice that creates a trip and fall hazard.

Spray head on a riser next to a sidewalk creates a trip hazard.

Not all landscape hazards are visible.  Turf areas may have grade depressions or holes that are hidden by overgrown turf grass.  Depending on the cause and time period, turf grass may completely hide the depth, location and size of the depression or hole, creating a hidden hazard.

A depression, rut or hole may result from several factors.  Repeated mowing on saturated turf may  create ruts.  Overwatering may cause irrigation or utility trench settlement.  A dead tree removed from a turf area may result in a future depression if the grade is not properly backfilled and compacted.

A seven inch deep hole hidden by turf grass.

Bermuda grass is a fast horizontal spreading turf-grass used in parks and recreation facilities throughout the country.  Unless regularly aerated and de-thatched, Bermuda grass in known to grow a  thick layer of thatch.  Over time, the thatch layer can increase the turf grade several inches above adjacent sidewalk and curbs.

The backfill in utility trenches installed across pre-existing turf may settle, creating a depression in the sub-grade.  The photo depicts the edge of a trench cut across an asphalt driveway, across a turf area.  The trench backfill eventually settled, creating a trench sub-grade depression hidden by the Bermuda grass.

Thatch, hidden depression and sanded turf.

The depression resulted in a trip and fall accident.  After the accident, several hidden turf depressions were “sanded” to fill  depressions to proper grade.

Not all landscape hazards are open and obvious.  Even a perfectly installed landscape may develop hazardous conditions if not regularly inspected and maintained.

Irrigation systems should be monitored, inspected, tested and adjusted monthly.  Turf should be trimmed around utility boxes and vaults regularly, aerated and de-thatched annually to maintain optimum performance and minimize grade changes.  Drainage structures should be grade adjusted, repaired or replaced when damaged.  Valve, electrical and junction boxes should be monitored for grade changes and adjusted as required.  Bark mulch thickness should be monitored and supplemented annually to maintain proper coverage and grade.

In summary, a properly installed landscape is composed of several systems and components that require regular ongoing maintenance for optimum performance, efficiency and safety.  Pro-active landscape maintenance may reduce potential hazards, resultant accidents and lawsuits.  These actions demonstrates an Owner’s recognition of protecting the health and safety of the public, pedestrians, friends and family who may visit and use the site and may prove useful in a legal action.

Botanical Skills by Matt Ritter, Ph.D, A Great Workshop!

With the intent to continually learn new information, stay up on new industry trends, laws and practices, I attend lots of seminars, workshops and continuing education courses. Most of the seminars have been informative and useful, and for the most part, the speakers have been entertaining in presenting their material.

Lets face it, learning new information is not always fascinating or interesting, especially when the topic is technical in nature. Or, the topic might be informative but the speaker might not have the best oratory skills to keep one fully involved and listening or absorbing the message.

When I attend an industry seminar, my intent is not only to learn new information, but to hopefully gain knowledge and facts that I can integrate into my consulting practice. Typically, I manage to come away with a tidbit or two that I might be able to incorporate into my practice, sometimes more, sometimes less. After all, when a seminar is advertised, it usually comes with a schedule of speakers throughout the day, and a brief line or two about what they will present during their allotted time slot. From that brief description, you make your decision whether the speaker and seminar is worth attending.

About a year ago, I got word of seminar about Eucalyptus tree identification, taught by Matt Ritter, Ph. D., a professor of Botany at California State Polytechnic University, San Luis Obispo. Colleagues told me to not miss the opportunity to attend the seminar because Matt was an incredible, knowledgeable, and entertaining speaker and I would learn a great deal of information.

So, I signed up and attended the seminar, it was in San Diego at Balboa Park. I was astounded, blown away and extremely impressed by Matt. He presented Eucalyptus tree history, biology and identification in an easy to understand, creative and entertaining manner. He provided handouts, identification keys and practical, useful information I incorporated into my practice immediately and continue to use frequently.

About a month ago, I received an email informing me Matt would be teaching a one day workshop in botanical skills and tree identification in San Diego at Palomar College in San Marcos. I signed up immediately and attended the seminar yesterday. WOW!! Once again Matt provided a powerful workshop discussing a wide range of topics including an introduction into the history of scientific and common plant names, botanical nomenclature, how plants get their names, why plant names change, plant morphology, keys, and identification. We had mini workshops and quizzes, worked outdoors practicing tree identification using keys designed by Matt, learned online resources for plant identification, names and inventories. It was an action packed, informative, practical seminar that was presented in simple, basic terminology we could all understand.

You can really get a sense of Matt’s love of botany, trees, and plants and his enjoyment at teaching and sharing his knowledge and experience. He provides manuals and handouts that are useful, practical documents that I put to use immediately in my consulting practice. He is accessible and willing to share his information rather that horde it and not allow others to use the information he teaches, a trait not often seen in other university educators. How many speakers do you know who encourage you to contact him or her concerning tree and plant issues or tell you it is okay to take his printed information and teach it to others?

In closing, just wanted to thank Matt for providing such a great learning environment. If you are interested in trees and plants, whether a student, consultant, arborist, horticulturist, landscape architect, agency or park representative, you owe it to yourself to attend one of his seminars. You won’t be disappointed. Visit his website at Matt Ritter Website