The headwaters of the North Fork of the Crooked River are being restored on the Ochoco National Forest east of Prineville. The watershed restoration project is designed to turn a dried-up prairie into a sponge.
Williams Prairie is about 45 miles east of Prineville at 4,700-foot elevation in the Ochoco Mountains.
Located there is the headwater of the North Fork of the Crooked River. The surrounding prairie doesn’t have a naturally high-water table anymore, so it changes the ground and the landscape.
“Exactly. You can see the drier vegetation up on the flatland and what should be wetter vegetation,” said Rob Tanner, assistant hydrologist for the Deschutes and Ochoco National Forests.
What’s the solution?
“We’ve got a plan to fill this into the brim. Basically, that’s putting the plug in the bathtub. Instead of water running off the landscape, it’s now going to be on top. That sponge of the prairie will be back,” Tanner said.
The first phase of restoration is filling in and leveling ground over four miles of deeply eroded stream gullies within the prairie.
Adding additional soil will result in restored water tables closer to the historic ground surface, which will allow for the growth of a complex riparian area and an overall healthier stream, meadow and prairie.
This kind of restoration has been done before and it works.
“It’s amazing. We did a similar project over on Deep Creek and the natural regeneration of vegetation — riparian, water-loving vegetation — came in pretty quick. The seed is here, in the soil. All it needs is water,” Tanner said. “Once we get that water back on this surface and saturate this, a lot of that is going to come back naturally. The Forest Service has also put in a request for riparian vegetation. Next spring, we will have a planting contract and we will plant some of that vegetation — sedges, rushes, willows.”
When we visited, a Youth Conservation Corps crew was planting the newly filled-in ditches, which were turning muddy before our eyes.
“You dig a hole. You use a longer bladed shovel and just stick it in. It has to cover it fully and then pack the mud around. These ones, the sedges, they like really gushy, sink right in kind of mud,” said LT, a YCC Team Leader.
They were finding plenty of muddy, gushy stuff.
“Oh yeah. It just keeps getting better by the day. A crew was out here last week, and the ground water is spreading so we get more spots to plant which is awesome,” LT said.
Once this restoration is complete, the Forest Service expects the watershed will be more resilient to a warming climate.
Benefits should include a more gradual release of cooler, naturally filtered water downstream, increased forest health, improved wildlife habit, better and higher forage production for wild and domestic animals outside of restoration areas and less invasive weeds.
“Once we filled in the downcut and degraded stream channel below here, this is Sera Spring, the water in this hole came up 3.5 feet,” Tanner said. “You can get an idea of the groundwater that’s in this system right below this spring.”
To protect the restoration efforts, temporary fencing has been constructed around the prairie and the area will not be available for livestock grazing for the next few years.
Restoration project managers use LIDAR — light detection and ranging — to determine where to fill and where to cut to restore the prairie.
“We run a transect down the middle of the valley. Off that valley transect we run multiple cross sections. Then we can figure out a geomorphic grade line we like. Come out here and ground validate it, ground truth it. Then we can come up with the elevations we want. And as you can see it’s all color coded. Then we use GPS equipment to make it really easy to know the elevations we need to hit with the equipment,” Tanner explained.
The public may encounter off-road dump trucks and equipment on forest roads in this area on the south end of the Big Summit Prairie on the Paulina Ranger District, but only brief road closures are planned.
A lot of this is going to be lush when it’s all finished.
“This is going to extend throughout this valley. We’ve done similar projects to this, and the vegetative response is quite amazing, how fast it comes back. I really think give it two to three years and you won’t even know that we were here.”