The proposed project will install a new 6'-3" by 20'-8" corrugated steel pipe arch culvert under South Norma Street in accordance with the City's Master Drainage Plan for Bowman Channel. Bowman Channel, originally constructed by the City, carries storm water flows from west to east from approximately S. Downs Street to SR 178. The channel is not hydrologically connected to any natural waterway, and South Norma Street blocks flows from the west to the east. As a result, storm flows ponds on the west side of South Norma Street, and accumulate sediment has created a flat area in the eastern downstream channel segments under South Norma Street. to allow storm flows to flow down stream within the channel.
The eastern segment of Bowman Channel receives storm flows via two (2) 24-inch culverts that are located on the immediate northeast corner of South Norma Street and Bowman Road.
In addition to the culvert installation, the channel will be re-graded to conform to the original design grade, riprap rock will be placed along the channel, and "check structures" will be placed across the channel bed to reduce the water flow force and to trap sediment, protecting the culvert from early failure.
The habitat assessment performed for the project (ELMT Consulting, 2020) indicates that there is approximately 0.47 acre, comprising 2,065 linear feet, of jurisdictional "waters of the State" in the project footprint, and that 0.003acre/26linear feet would be permanently impacted (see figure 2 below). The City will submit a Clean Water Act Section 401 WDR (water dredge-fill) application to the Lahontan Regional Water Quality Control Board, and a Lake and Streambed Alteration notification to the California Department of Fish and Wildlife to determine if permits are required. The habitat/jurisdictional waters report is available on request from the City of Ridgecrest, Department of Public Works; contact information provided above.
The project has independent utility and will not require future construction to function. The project does not require new right-of-way for construction. The project does not involve landscaping activities that use known invasive plant species. All work is within operational right-of-way.
Setting: Norma Street is bordered by residential, commercial and institutional land uses. There is no natural habitat within or immediately adjacent to the project boundaries. The habitat assessment performed for the project concluded that there is minimal to no habitat value in the engineered channel bed, and found no evidence of protected plant or animal species. See Project Location aerial view (Figure 2) below.
Beneficiaries: The general public will benefit from improved floodwater management, including reduced ponding in the channel. Reducing ponding will minimize the need for vector control in the channel.