WHY ARE THE TRAILS CLOSED?
On October 30, Friedrich Wilderness Park (FWP) received over 7” of rain in less than 24 hours. Not only was the Water Trail spring gushing, but springs and waterfalls appeared where they had never been seen before. The result was significant flooding that washed out trails, scoured hillsides, and left debris everywhere. This was followed by more rain on October 31, which made it impossible for the trails to begin drying. The wet weather continues, and so the trails cannot dry, and we are limited in what repairs we can make.
There are several factors that contribute to the magnitude of the impact of rain on FWP trails. The terrain is hilly with many steep slopes and the soils are thin. Moreover, most of the trails are more than 30 yrs. old, heavily used, and already significantly eroded. Some trails run straight up/down hills, so-called fall line trails. Water naturally follows the path of least resistance, so when it rains, these fall line trails become little streams. Even where the trails are built into the contours, there is still water that flows down the slope and across the trail, leaving debris berms that disrupt sheet flow.
Sustainable or not, all trails are impacted by traffic, and the impact on natural-surfaced trails is magnified when they are wet. It is just a law of physics that people (and animals) leave depressions and ruts on wet trails. These ruts, like the berms on the trail edges, impede sheet flow so that the trails become conduits for water. Instead of water flowing across the slope and down the hill, the water is essentially trapped on the trail. The result is erosion and debris berms.
Slips and slides, exacerbated by slick trails, result in trail widening, and clumps of soil that stick on shoes essentially “walk out” of the park. Moreover, staff cannot work on wet trails without the danger of doing additional damage.
Best management practices as well as a concern for patron safety require that trails be closed when they are wet. Friedrich Wilderness Park is joining the San Antonio River Authority, Government Canyon State Natural Area, and other state and national parks, in implementing a policy of closing wet trails. In an effort to make this as easy as possible on patrons, we are leaving the Water and Forest Range trails open. We will reopen all the trails as soon as we can. Meanwhile, please help limit trail damage by obeying trail closure signs.
If you have questions, feel free to contact Natural Areas Assistant Manager Robert Rinn (210.207.3718, Robert.Rinn @sanantonio.gov).