The #1 top project for Storm Water Solutions 2020 Top Projects.
After the Carr Fire in California in 2018, which burned 229,651 acres in Shasta and Trinity counties and destroyed 1,604 structures, the Western Shasta Resource Conservation District got to work on treating the high-severity burned areas.
They applied erosion control best management practices (BMPs) to 1,169 acres and 659 parcels selected for treatment. Practices included native and rice straw, hydraulic bonded fiber matrix, native perennial and annual seed, slow release fertilizer and mycorrhizae inoculant. This helped the project team reach its goals, which included reducing sediment transportation to stream systems associated with the Sacramento River and protecting waterways critical to the Sacramento River Fishery.
Following the installation of the BMPs, sediment delivery data was collected in a series of mentoring plots and stations by WSRCD and the Water Quality Control Board. They found that, overall, vegetation cover was highest on straw-treated areas (91%) followed by hydraulic treatment (74%). Untreated spots showed the least vegetation cover (33%).
Nearly 12 times more sediment was transported to downstream locations on untreated areas than areas treated with straw, seed, fertilizer and mycorrhizae. Additionally, the sediment collection data saw a reduction in the rate of erosion over four times that of untreated slopes when hydraulically treated.
“It’s quite amazing to see how the landscape can recover, especially with some assistance. The charred landscape after the fires transformed into green hillsides covered in native seeded grasses, wildflowers and resprouting shrubs,” said Sarah Seiler, project coordinator.
To treat the burned areas, two treatment strategies were implemented; a manual hand application procedure, which included either rice or native straw, and a hydraulic application, which involved hydro-seeding with bonded fiber matrix, which is made of three native grasses, one native forb and a sterile hybrid.
Crews from the California Conservation Corp. and California Correction Facility hand-applied material to 933 acres of burned areas at a rate of approximately 2 acres per day per crew, and each crew had 15 people on it.
After they hand-carried the straw bales to the site and applied the materials, they laid straw so 100% of the soil surface was covered. On the hydraulically applied approach, Selby Soil Erosion Control applied materials to 236 acres treatment areas at a rate of 6 to 7.5 acres per day (eight to 10 loads) by crews of three.
“This project is important because the scale and nature of this project made it unique and the first of its kind in Shasta County and for the Western Shasta RCD," Seiler said. "As catastrophic fires become more common in the west, projects like this can provide simple, effective solutions on how to prevent further damage to post-fire watersheds and ecosystems. This project can help inform future land managers, while providing a blueprint on how to conduct large scale, collaborative, emergency response restoration work.”
The project is now complete, though monitoring is still ongoing, and preliminary data shows there is a significant reduction in erosion and sediment transport.