Wednesday, March 21, 2012

Why You Shouldn't Build Trails Close to Water

Streams and rivers are beautiful and they are a natural point of attraction along trails.  In fact on longer trails, it is important to bring the trail close to running water to provide drinking water for backpackers, pets, or pack animals.  Given all this, it is perfectly understandable that trail designers often want to place their trail right along a creek, but it turns out that is a horrible idea.  In honor of this week's large amount of rainfall, here are some reasons why you shouldn't place your trails too close to a stream or river.

Trail in Golden Colorado Closed due to Flooding. Photo by Jess Daniel
1.  Money - If you build too close, you will lose your trail after one or two flood events.  The
University of Arkansas learned that lesson when they lost a section of trail that was built along the normally tiny and calm Mullin's Branch.  I cited this and other examples when advising UALR not to build the Coleman Creek Greenway too close to the creek.  The photo below shows another example of costly damage resulting from placing a bike/pedestrian trail too close to a creek.

Be sure to look for evidence of rapid bank erosion and find out how large the floodplain is where you are building your trail.  Seemingly tiny creeks can easily rise 6 or 10 feet following a large rainstorm.

2.  Safety and Usability - No one can use a trail when it is 3 feet underwater.  Placing a trail just 10-15 feet away from the creek might mean it can be used 10 more days of the year.

3.  Time and Effort - In addition to money, it takes a lot of time to rebuild sections of trail that get washed away.  Even if your trail doesn't get washed away, it takes time and effort to clear mud, sticks, rocks, and other debris deposited by a flood.  The trail below has been damaged for nearly a year and has yet to be repaired.

4.  Habitat and Water Quality Protection - Building a trail, paved or unpaved, along a stream edge can damage vegetation and encourage streambank erosion.  Increased bank erosion harms water quality and destroys habitat for many species of fish and other aquatic organisms.

If you want to avoid these issues, simply place your trail a reasonable distance away from the stream and either add short spurs to the water or occasionally bring the trail closer where the bank is a little higher or looks most stable (see examples below,  Red=Bad  Green=Good).

For more information on how to save time, money, and energy on trail maintenance, visit my Building Trails page.

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