Excavation of the stream channel on Reach B is nearing completion and initial revegetation work is underway
Its been an exciting and fast-moving month since the last post. Open Space staff has been meeting with the contractors weekly throughout the construction phase, to review progress and give input. We also led a field trip with project partners from Colorado Parks and Wildlife, as well as the US Fish and Wildlife Service. It has been great to share the results of our work and fruits of our labor with our partners, which aligns with the goal to create an example for other restoration projects to follow and build off.
The team at Ecological Resource Consultants and Tezak Heavy Equipment has been doing some incredible work on Reach B of the Swan River and the results are easy to see. Work has not only progressed quickly, but has also included some tremendous improvements over Reach A through alternative bank stabilization, incorporation of local transplants, variation in stream width and depth, and the installation of side channels and islands, as well as step pool wetlands. In this post, I will walk you through the construction process and show examples of the work in progress, as well as the final product.
The first step towards creating a functional stream is excavating the channel and giving the water a place to flow. This initial "roughed in" channel included all the basic shaping and placement of the channel, as well as mass grading and soil placement adjacent to the new channel. This channel excavation phase also included the installation of a run down channel on the upstream end of the new channel to collect surface flows during spring runoff. Our contractors started work on this phase in Late July and early August and the new channel is now fully in place.
08/14/21 - Initial Excavation of the stream channel along Reach B. The first step towards creating a functional stream is "roughing in" the channel.
08/20/21 - Initial Excavation of the stream channel along Reach B. Following the "rough work", the contractors staged soil, cobbles, and boulder features for habitat installation and fine grading at the later stages.
08/26/21 - Aerial images of the site showing completed (top, right) and in-progress stream excavation (bottom, left).
09/14/21 - The new run-down channel to collect surface water from the upstream reaches. Ground water and surface flows will fill the newly created channel.
Bank Stabilization and Habitat Feature Placement
Following stream excavation, bank stabilization and habitat feature installation were completed next. Over the past month, the stabilization and in-stream habitat features of the river were installed including large woody debris, boulders, islands, and willow transplants, as well as the riffle-pool-glide sequences which give the stream channel variability in depth, velocity, and general morphology, mimicking natural stream systems in similar substrate types. Once these features were installed, final grading and soil placement along the channel were completed and the site was ready for initial revegetation and erosion control work.
09/14/21 - Installing in-stream riffle-pool-glide and boulder habitat features in the upstream portion of the new channel.
09/20/21 - Large woody debris staged for bank stabilization. All wood used in outside bend features was collected on site.
09/20/21 - Completed outside bend with large woody debris bank stabilization. This technique provides complex habitat features that serve as fish refuges.
09/26/21 - Transplanting willows to outside banks. Mature willows harvested at the site will help stabilize the banks during spring runoff and provide shade for aquatic species.
09/26/21 - Completed habitat and stream features include bank stabilization, willow transplants, islands, and wetland features.
The final phase of construction occurring in 2021 is the initial revegetation of the site and placement of erosion control devices to help keep everything in place. The team at Western States Restoration is progressing this work, as I write. Initial revegetation consists of; fertilization of the site to ensure adequate nutrient availability for establishing plant communities, planting the entire restored area with the appropriate riparian (near stream), transitional, and upland seed mixes, and installing biodegradable erosion control fabric and straw logs.
09/26/21 - Erosion control blankets were installed along the rundown channel and in the near-stream riparian areas, following fertilization and seeding
10/01/21 - An outside bend nearing completion. Habitat features, willow transplants, seeding and erosion control are finished and planting pockets will be added in 2022.
Reach B work to continue into 2022 and beyond
Next season, we anticipate completing the restoration of Reach B, which will conclude the large-scale restoration efforts on the publicly-owned portions of the Swan River. Work in 2022 will include reclamation of the gravel stockpile site (about 5 acres) including ripping, contouring, soil placement, and revegetation of that area. In the areas currently being restored as well as the stockpile area, large scale planting of trees and shrubs will take place in 108 "planting pockets" across the site. These pockets will consist of densely planted clumps of trees and shrubs located in small depressions which are back filled with top soil and finished with a layer of mulch. By planting vegetation in theses clumps, or pockets, the moisture and nutrient retention in these planting areas will be maximized by diverting water to the depressions, minimizing evaporative losses by creating shaded areas and adding mulch, and creating a natural, nutrient-cycling dynamic within each pocket. After we conclude the installation and construction phase on Reach B, 5 years of US Army Corps of Engineers monitoring will be required, along with additional monitoring done by the County and its partners, including vegetation monitoring, cross sections of the stream channel, and fish population assessments through electrofishing surveys.
Updates on Reach A
2021 is the last year of Army Corps required monitoring on Reach A. We will continue to keep monitoring this stretch of river through observations by staff, as well as fisheries surveys performed in conjunction with Colorado Parks and Wildlife. We are constantly looking for ways to improve Reach A. The Open Space and Trails Department has engaged volunteers from the Blue River Watershed Group and the Sierra Club to collect and redistribute native seed on the Reach A site, focusing on areas where vegetation is sparse. Along with collecting and distributing seed, these volunteers have added top soil and compost to these areas to encourage the establishment of additional vegetation.
Open Space staff is also working to form a new partnership with American Forests to install planting pockets on Reach A, similar to what will be installed on Reach B. By increasing the diversity of vegetation species and density on Reach A, the opportunity for new habitat types to establish is also increased. These pockets would be planted with aspen, blue spruce, Engelmann spruce, and bristlecone pine, as well as big sagebrush, antelope bitter brush, and wax current. We will continue to provide updates on any new work occurring on Reach A and give volunteers the opportunity to contribute to this amazing work!
For more information and to sign up for volunteer opportunity notification, please email Jordan Mead, Resource Specialist at firstname.lastname@example.org or give me a call at (970) 668-4065.