Title

Draft Environmental Assessment of San Bernardino County Department of Public Works for the Desert Knolls Wash Phase III Construction Channel Project

Document Number

N2024030

Document Type

EA/FONSI

Project Description

The Proposed Action will take place in the Town of Apple Valley in San Bernardino County, California. The Proposed Action consists of bank and invert stabilization improvements along an existing 0.6-mile segment of the wash. The wash side slopes will be graded to a 2:1 slope and grouted and ungrouted rock will be installed to protect the slope. The channel bottom will vary from 30 to 150 feet wide. The wash invert will mainly be earthen. Rock inverts will be constructed at sections of expected high erosion. The grouted rock side slope revetment and grade stabilization structures will extend below grade at the toe to below the anticipated scour depth. The channel will then discharge flows back into their natural flowpath with a 25-foot wide embedded scour control structure spanning the width of the channel as it exits. Construction of a paved and partially fenced continuous access road along the southern side of the wash will facilitate maintenance and access. The access road will also cross over the wash in the northern end of the Proposed Action area, requiring the construction of a concrete box or arch in the northern section of the wash.

EPA Region/Headquarters Office

9

State or Territory

CA

Point of Contact

Elizabeth Borowiec
415-972-3419
Borowiec.Elizabeth@epa.gov

Date of Issuance

2024-01-31 00:00:00.0

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