Valley Creek Ravine 2E Stabilization Project

In 2019, Valley Branch Watershed District (VBWD) received a $405,000 Clean Water Fund (CWF) grant for the Valley Creek Ravine stabilization project. This project will continue to protect and improve Valley Creek, a world-class trout stream in the VBWD. Stabilizing Ravine 2E, which conveys runoff from a 150-acre watershed directly into the main stem of Valley Creek, will prevent approximately 7.8 tons annually of sediment from depositing in the creek and silting over trout spawning sites. It will also reduce the annual total phosphorus load to Valley Creek and the nutrient-impaired Lake St. Croix by approximately 52 pounds per year.

This project, located on three private properties, north of Valley Creek Trail and east of Neal Avenue South in Afton, was initially identified in the VBWD 2005 Valley Creek Erosion Inventory Study that identified and prioritized projects watershed-wide to improve the water quality and habitat of Valley Creek. The site was revisited in 2008/2009 and again in 2018 when VBWD pursued the CWF grant. Ravine 2E is typically dry. It is a steep ravine with exposed bedrock along much of the channel bottom. There are three actively eroding head cuts along the flow path: one along the drainage path in an open field upstream of the ravine (~3–4 feet deep), a second in the upper ravine (~3–4 feet deep), and a third in the lower ravine (~2–3 feet deep). The CWF grant project will provide rate control into the ravine, repair and stabilize the actively eroding head cuts, and stabilize a steep actively eroding bank at the lower ravine site.

The project includes the construction of a runoff rate-control/infiltration basin at the head of Ravine 2E that will allow infiltration of runoff, address existing head cutting, and control peak discharges into the ravine. This area will be restored as mesic prairie, similar to the vegetation within the existing drainage way. The project also includes using riprap to stabilize the head cutting at the upper ravine site and vegetation in areas disturbed by the riprap installation. At the lower ravine site, riprap will be used to stabilize the head cutting and the toe of the ravine’s east bank, where runoff is beginning to undercut the bank. On the west bank, where the slope is actively eroding, the construction plans involve grading back to a shallower slope and establishing riparian vegetation to stabilize the graded slopes and disturbed areas within the ravine.

Since the CWF grant was secured, the VBWD was also approached by the owners of the property to the east of the proposed basin. They identified a small area of erosion on the boundary between the properties along an existing drainage way. This area is easily accessible from the basin, and the project plans include placing some excavated material and stabilizing and restoring this small area. 

The CWF Grant project is in the process of securing easements with the private property owners.  Additionally, the project is in the process of being publicly bid, with project bid opening on July 9, 2021.  Project construction is anticipated to begin in August 2021 with substantial completion by October 31, 2021.

The following table summarizes the CWF amount, the VBWD local match funds, and the total project budget through May 21, 2021:

Funds

Budgeted Amount

Budget Spent

% of Budget Spent

Clean Water Grant1

$405,000

$61,298.12

15%

VBWD Match Funds2

$112,000

$6,249.50

6%

Total Project Budget

$517,000

$67,547.62

13%

1 – Includes project design, permitting, construction oversight, and construction cost.  Planning level construction cost is $300,000.

2 – Includes easement coordination and acquisition costs

 

View a map of the project area (.PDF)

Project Details (.PDF)





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