Watershed crew builds road crossing in Warpath Valley
by Leanna Cox, Watershed Summer Intern
This June, the Tó Nizhóní Ání (TNA) crews spent the week working alongside engineers from natural channel designs in Warpath Valley, Kits’iili, building restoration structures and preparing the watershed for the summer monsoon season. One project stood out from the rest this session: a road crossing utilizing wool as geo-textile matting designed to help reinforce a section of road while using materials sourced directly from the community.
Road crossings can be some of the most challenging places to protect. During flooding events, water rushes through washes, cutting deeper channels into the roads that stand in the way of floodwaters. Over time, crossings become increasingly more difficult to access and more vulnerable to damage.
To address this issue, the crew and engineers worked together to design and build a road crossing using donated wool as a natural geotextile to help the structure stay stabilized by acting as a layer to soak up and slow water during flow periods. While many restoration projects rely on synthetic geotextile fabrics that are generally made from plastic, TNA’s Watershed Restoration Project has been taking a different approach in their work. Local sheep owners have donated wool that would have otherwise gone to waste that can now be repurposed in watershed work in many ways, sheep’s wool has helped the crew build crossings, dams, bowls, and reinforce many of the different structures in the watershed.
The biodegradable wool will never need to be dug up and removed; it will eventually break down and return to the land rather than remaining and posing unnecessary ecological harm. Some wool infused features have been proven to stay in the ground and work effectively for 20+ years!
The crew from Channel Designs also recommended incorporating a cross-vein weir into the downstream side of the crossing. The team was able to move massive, heavy boulders with the help of a tractor to make the weirs foundation extra fortified and stable. The utilization of the weir helps to create a road where water can flow over the surface in a flood event without cutting into the dirt too dramatically and erode it away. This structure, with the leveling and stabilization of the road, and several One Rock Dam’s placed upstream is sure to show promising resilience in the event of a flood.
As monsoon season approaches, the crossing stands ready for its first test. Whether the rains arrive tomorrow or later in the season, the work completed in Warpath Valley reflects TNA’s commitment to restoring Kits’iili’s watersheds.
