Feature Article - October 2009
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Blazing a Trail

Designing & Maintaining Trails for Today's Users

By Kelli Anderson

Watershed Moments

Without a doubt, however, the biggest design flaw comes down to one word: water. No matter how scenic or creative a trail system might be, if trails are not built to shed water properly, the result will be wasted time, wasted money and needless safety hazards.

It starts from the bottom up. When soils are not properly understood, gradients too low or trails insufficiently outsloped, trails become waterways eroding into gullies, creating impassable trenches and exposing hazardous roots and rocks. "The key is angles and drainage," Mittenthall said. "It's about tilt and reverse grade. We just have dirt and clay—it hardens if you keep the water off. In bottom soils we use a textile with gravel to fill in. As long as you keep water off, you can get soil to mineralize like cement. You can walk on my trails when it's raining because of the tilt."

With a 10 percent gradient considered a good standard (except for highly erosive sandy soils) and cross-slopes of 3 to 4 percent to quickly shed water, trails stand a much better chance of standing up to the watery elements and reducing the need for labor-intensive maintenance and repairs.

Scratching the Surface

"In general too much energy in a budget goes above ground and not enough goes to the surface," said Jim Dobmeier, president of a rubberized surfacing manufacturing company. "It can make all the difference in the world. Some surfaces even attract people—they'll drive out of their way to enjoy that kind of experience. It's a mistake not enough attention is paid to it."

Trail surfaces come in many varieties; choosing the right one depends on its purpose and the natural environment. In the midwest, for example, clay soils—the bane of the farmer and gardener—are the darling of the trail-forger, hardening its mineral-packed soil like cement when exposed to the sun. In the northwest where trees are abundant, wood chips are a renewable resource and a comfortable surface material that reduces soil compaction. In the northeast, lush greenways of grasses and low-growing ground covers reduce erosion and retain snow coverings for cross-country skiing and snowmobiling.

Solid surfaces such as asphalt, stone dust and increasingly popular rubberized surfaces, are ideal for many uses and greatly reduce the need for maintenance. They are also the best solution for high-traffic areas and for accessibility.

Another solid surface treatment is boardwalks. "In areas of poor soils and in wetlands we typically use a boardwalk system," Burch said. "Solid surfaces are suitable for a variety of seasonal uses, easy to maintain and offer a durable, accessible and cost-effective surface."

And while "cost effective" may not be the first thing people tend to associate with solid surface trails, the term begins to make more sense when the annual costs of maintenance materials and manpower for their natural surface counterparts are factored into the equation.