1. UNDERSTAND THE TERRAIN.
The upper portion of Williams Canyon, far above the steep rock walls familiar to locals, has been the source of most of the flooding problems that have plagued Manitou Springs this summer. Once thickly forested, the area was left black following the Waldo Canyon Fire.
From a mitigation standpoint, Williams presents a challenge. Its upper reaches are remote. Ideally, crews work in this area with heavy equipment that enables them to build the large structures necessary for this massive watershed. But much of this area simply isn't accessible to machines. This gully falls in the latter category, meaning all work here must be done by skilled workers whose most advanced tool is a chainsaw.
The good news is that summer rains have ushered in plenty of greenery. Plants intercept rainfall, allowing soil a better chance to absorb water. Plus, plant roots break up hydrophobic soils and hold the ground in place. Tree growth will be slower, but a walk through the forest reveals a wealth of plants, including a variety of forbs and perennial bunch grasses, as well as a rainbow of wildflowers. A few small aspens have also popped up.
Water has been so ubiquitous this season that it has transformed ephemeral streams into perennial flows in Upper Williams Canyon. Hand-workers have nevertheless slushed through the stream bed of one key area to build structures that can harness flood waters.
"There are two drainages that kind of feed Middle Williams," Rocky Mountain Field Institute Program Director Amber Shanklin explains. "... This is one of the drainages."
2. FIND BRAWN AND BRAINS.
Hand-workers with the Coalition for the Upper South Platte were busy mitigating Wellington Gulch on western Ute Pass when they agreed to relocate here, where RMFI workers were already toiling. Williams Canyon has been a priority for the two nonprofits over the summer because floods from it have caused the most damage to homes and businesses. Still, the nonprofits have other sites that also need attention. RMFI's men and women were finishing its work — at least for a little while — in Upper Williams when we toured the area.
They will be missed. While some areas affected by floods can be helped by teams of eager volunteers, most tasks in Upper Williams require skilled crews. Even the tasks that don't require heavy machinery are dangerous, grueling and technical. The crews we witnessed — mostly women — were hard-bodied, and smeared in dust, sweat and ash. One woman, we heard from Shanklin, had held a record for rock climbing a route up the famed El Capitan in Yosemite National Park.
That kind of strength and endurance is crucial to a job that requires long days in the sun, chopping trees, digging ditches, hauling logs and hammering rebar. But when it comes to handwork, brawn is worthless without the technical precision to build structures that control flood waters instead of being absorbed by them.
"The training that's required for this — I mean it's a pretty steep learning curve," Shanklin says. "... Frankly, the Forest Service doesn't want just anybody out here; they want people who know what they're doing. Because, again, you could cause a lot more damage than not doing anything."
3. SAW, SHIFT AND SEED.
One of the most basic structures that workers build in steep areas like this is the log erosion barrier, or LEB.
Trees are cut and sawed into logs. Then the logs are dug into the ground and secured in place. Grass seed is planted behind the log. When water comes down the hillside, it hits these small terraces and drops much of the mud and gravel it's carrying.
Effective and simple, LEBs have been installed in swaths of this drainage. Shanklin notes they could serve a purpose throughout these hills, provided that they have been installed properly. (Even the simple LEB must be "perfect" to do its job, and to avoid washing downhill and becoming part of a flood torrent.) But with resources limited, much of the drainage will go untreated.
"We could put LEBs all over these," Shanklin says, staring out at the hills. "It may not be as effective as working in another area."
4. LEARN FROM YOUR MISTAKES.
Sediment that isn't caught on the hills can, to an extent, be caught by structures built directly into a stream bed. Those structures are more straightforward when machines can be used, but they can be tricky when only hand tools are available.
When RMFI crews first began working in Upper Williams, they built structures similar to ones they had erected in small streams in other remote areas. But when Williams floods, it carries thousands of cubic feet of water per second. The little structures failed.
"The first couple were definitely a learning process," says RMFI field instructor Aaron Mojica. "We built one right before those early July storms and it was both good and bad that we had those storms come through, because they showed us what we were doing wrong."
The crews tweaked the structures in several ways. First, they made them bigger. Second, they made them stronger, abandoning a Lincoln Log-type construction for heavy-duty supports. Third, they borrowed design elements from a structure invented by famed hydrologist David Rosgen for large-scale, machine-built structures, then adapted it for smaller, hand-built dams.
The resulting miniature log dams, called "crib walls," proved effective in the Aug. 9 deluge.
"The bottom log is pounded into the ground like, three feet with rebar," Shanklin says of the crib walls. "Every log on top of that is nailed in with those 10-inch spikes, then they're [dug] into the banks, and then these dead-men [a type of anchor] are supposed to support them as well. They're a beefy structure."
The crib walls are working. Built in zig-zag fashion to direct water and hold back sediment, some have already filled to the top with sediment that would have otherwise flowed downstream. While those structures won't be able to contain any more sediment in the future, they will continue to create waterfalls that slow the flow of water down the canyon.
Smaller structures also serve to collect sediment and direct and slow water.
5. PICK YOUR BATTLES.
Farther down the canyon, the mitigated estuary meets a larger waterway, which has not received the volunteers' attention.
The junction bears the scars of recent floods — small canyons of gravel and sand carved by fast-moving waters, a scattering of large boulders, logs strewn like Pick Up Sticks. Some burned ponderosas show recent scars on their lower trunks, where water and debris have cut deep.
"You can clearly see the difference between this drainage that we're working on, where there's not a lot of sediment, and this drainage where it's just all sediment coming through," Shanklin says. "It's really a stark contrast."
It is. Mitigation may not actually stop a flood in Williams, but it clearly slows it down. It makes the water manageable.
Unfortunately, workers won't be able to mitigate all of Upper Williams. Machines can only reach limited areas, and in bigger confluences, handwork won't hold up to the assault from boulders shooting downstream. Also, some smaller, higher-up streams are simply too remote.
"This was — I don't want to call it low-hanging fruit, because it was very important work — but it was fairly easy access because the road is right there," Shanklin says, pointing up the side of a large, steep hill. "But that's like what we're dealing with in Queens Canyon. A lot of work could be done out there, but the access is nearly impossible."
Shanklin says the next area RMFI will target in Upper Williams requires a two- or three-hour hike in — dragging equipment, and probably camping gear. They may ask AmeriCorps to help with that project, which is considered a high priority by the Forest Service.