Additional Project Facts
While it is expected that people may disagree with the necessity and merits of the ongoing flood recovery work along South St. Vrain Creek, Boulder County Parks & Open Space staff would like to clarify and correct some of the assumptions and misinformation appearing in the local papers and on social media.
While it is true that some trees were removed during the project, including a line of smaller, highly visible trees opposite the Hall Ranch trailhead, the vast majority, over 200, of the large trees and root wads that have been visible on site were hauled in from other locations. Most were trees that were salvaged along the St. Vrain immediately after the flood, and have been stockpiled north of Hwy. 66 near Lake McIntosh. Additional trees came from the Little Thompson, also salvaged after the flood, from a reservoir project near Lagerman Reservoir, and from the Town of Lyons stream work just east of the Old St. Vrain Road bridge. All dead trees were left standing where possible as we realize their role in providing wildlife habitat.
The trees cut along the Readmond farm were not part of the Boulder County project, but were cut by Poudre Valley REA as part of clearing efforts along their power lines.
No trees have been hauled to the Lyons Quarry, only sand and rock as part of our agreement with Aggregate Industries, which is also helping with the reclamation efforts that the mining company will be responsible for over the coming years. The new bridge will, in part, facilitate their access to the quarry so they don’t have to travel Old St. Vrain Road
With the exception of a few recent truckloads, all of the boulders and rock seen piled on the site were excavated from on site. The large boulders came out of old berms along the river, while the round river rock has been sorted and screened during the removal of sediment. Large areas of the meadow were filled after the 1969 flood, as is evident in the red soil and angular rock uncovered, which was hauled down from the andesite quarry.
The project has followed best management practices for erosion and sediment control in its storm water management plan, which includes placing erosion control logs to prevent sediment moving from the disturbed areas and construction fencing to protect existing vegetation. Construction of in-stream structures causes unavoidable, but short-term, sediment movement. Seeding and planting following construction will facilitate vegetation regrowth to further reduce erosion from disturbed areas.
While it is true that some areas rebounded with vegetation in the last few years, most of the areas being graded were still mostly bare sand and gravel, or were channels left over by the flood as of this year.
We have May 2017 drone flight footage that shows the extent of still bare areas. All efforts were made to save areas of vegetation, especially the large wetland area on the east end, while still meeting the design parameters allowing for increased conveyance, sediment capture, and infrastructure protection. Starting in October we will be planting over 4,000 trees and shrubs, over 9,000 willows, and 7,600 perennial wetland plants, as well as seeding with native seed mixes and mulching the entire area. With a lowered floodplain, plants will be that much closer to groundwater, and we expect areas that were high and dry will now be able to sustain a more vigorous and expanded riparian area.
The project has followed all federal and state guidelines for protection of breeding birds and raptors. August is typically the end of breeding bird season, and the contractor and county ensured that surveys were done weekly through the end of the month for breeding birds, as part of the federally mandated Migratory Bird Treaty Act. A few nests were found—swallow, warbler, and lazuli bunting—flagged, fenced off, and avoided until the birds fledged.