Magenta Drain Restoration
Summary
SCH Number
2026060020
Public Agency
City of Grass Valley
Document Title
Magenta Drain Restoration
Document Type
NOE - Notice of Exemption
Received
Posted
6/1/2026
Document Description
The Magenta Drain Restoration Project is a habitat restoration effort that will occur along an approximately 800 linear-foot segment of Magenta Drain within Memorial Park. Magenta Drain is a historically altered, artificial channel originally constructed in the mid 1800s to convey groundwater and mining discharges from the Empire Mine area. Although legacy mining contamination has been remediated, the channel remains highly degraded and ecologically impaired, characterized by a steep, uniform V-shaped profile, disturbed fill substrates, limited channel complexity, and a riparian corridor dominated by invasive plant species and nonnative ornamental trees. Existing conditions provide minimal aquatic or riparian habitat and limited ecological function.
The project will restore approximately 0.73 acre, with 0.67 acre (91%) consisting of habitat restoration activities. Restoration components include re-contouring the channel and banks in key areas totaling 0.09 acres to improve stability and hydrologic function, habitat boulder augmentation within approximately 0.08 acres to increase channel complexity and aquatic microhabitats (of this 0.08 acres, individual habitat boulders total 0.02-acres with the remaining area consisting of the existing substrate), and invasive species removal and native riparian revegetation across approximately 0.56 acres. Revegetation will utilize regionally appropriate native riparian trees, shrubs, and understory species to establish a dense canopy to improve shading and suppress reestablishment of invasive species while enhancing wildlife habitat. Approximately 0.03 acres of vegetated rock slope protection will be installed to replace an existing vertical retaining wall using bioengineered methods that stabilize banks while supporting ecological processes.
Minor recreational improvements totaling approximately 0.07 acres (9% of the project area) are included and are incidental to the habitat restoration objectives. These consist of a gravel trail (approximately 0.05 acres) and limited creek access steps and seat boulders (approximately 0.01 acres) to provide controlled public access and viewing opportunities while avoiding disturbance to restored habitats.
The project does not include new buildings, expansion of developed uses, or changes in land use designation. All work is limited to restoration and enhancement of an existing degraded drainage corridor. Upon completion, the project will result in a more stable and ecologically functional riparian ecosystem that improves habitat quality, channel stability, and ecological processes compared to existing conditions.
Contact Information
Name
Amy Wolfson
Agency Name
City of Grass Valley
Job Title
City Planner
Contact Types
Lead/Public Agency / Project Applicant / Parties Undertaking Project
Phone
Location
Coordinates
Cities
Grass Valley
Counties
Nevada
Regions
Citywide
Cross Streets
Central Avenue, Race Streets
Zip
95945
Total Acres
0.73
Jobs
4
State Highways
20/49
Railways
none
Airports
Nevada County Airport
Schools
BellHill,LymanGilmore,Scotten,MtStMarys,GVCharter,SilverSprings
Waterways
Magenta Drain, Wolf Creek, Little Wolf Creek
Township
16N
Range
8E
Section
28
Base
MDB&M
Other Location Info
Within Memorial Park, a municipally-maintained park
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
Section 15333, Class 33
Reasons for Exemption
This project consists of habitat restoration along an 800-linear-foot segment of Magenta Drain within Memorial Park to improve aquatic and riparian habitat and ecological function. The project is exempt under CEQA Guidelines Section 15333 – Small Habitat Restoration Projects. The project meets the conditions for this exemption as explained below.
Small Habitat Restoration (Class 33). Class 33 consists of projects not to exceed five acres in size to assure the maintenance, restoration, enhancement, or protection of habitat for fish, plants, or wildlife provided that:
a. There would be no significant adverse impact on endangered, rare or threatened species or their habitat pursuant to section 15065,
b. There are no hazardous materials at or around the project site that may be disturbed or removed, and
c. The project will not result in impacts that are significant when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects.
The Magenta Drain Restoration project involves restoration and ancillary recreation improvements on 0.73 acres. The restoration work will result in a more stable and ecologically functional riparian ecosystem that improves habitat quality, channel stability, and ecological processes compared to existing conditions and will not result in significant adverse effects as discussed below.
Exceptions to Use of a Categorical Exemption: As discussed below, the project does not have the potential to trigger any of the exceptions identified in CEQA Guidelines Section 15300.2 prohibiting the use of a categorical exemption.
a. Location. Classes 3, 4, 5, 6, and 11 are qualified by consideration of where the project is to be located - a project that is ordinarily insignificant in its impact on the environment may, in a particularly sensitive environment, be significant. This exception does not apply to a Class 33 Categorical Exemption, which inherently involves environmentally sensitive sites.
b. Cumulative Impact. All exemptions for these classes are inapplicable when the cumulative impact of successive projects of the same type in the same place, over time is significant. The City of Grass Valley does not anticipate any additional modifications to Magenta Drain or its associated riparian vegetation.
c. Significant Effect. A categorical exemption shall not be used for an activity where there is a reasonable possibility that the activity will have a significant effect on the environment due to unusual circumstances. The project will improve the aquatic and riparian habitat and ecological function of Magenta Drain and result in an improvement to the habitat value within the project site. The project is subject to permits from the U.S. Army Corps of Engineers, California Department of Fish and Wildlife, and Lahontan Regional Water Quality Control Board. Compliance with permit conditions will ensure there is no significant adverse effect to biological resources. The project will not alter operations or recreational programming of Memorial Park and will not result in any adverse effects to other environmental resources.
d. Scenic Highways. A categorical exemption shall not be used for a project which may result in damage to scenic resources including, but not limited to, trees, historic buildings, rock outcroppings or similar resources, within a highway officially designated as a state scenic highway. The nearest eligible Scenic Highway to the project site is State Route (SR) 174 (Caltrans 2026), which is locally signed as Ophir Street. The Magenta Drain Restoration project site is not visible from SR 174. Large trees are present between SR 174 and Memorial Park, and the Memorial Park tennis courts are located adjacent to those trees. The project site is located approximately 260 feet west of SR 174.
e. Hazardous Waste Sites. A categorical exemption shall not be used for a project located on a site that is included on any list compiled pursuant to Section 65962.5 of the Government Code. The project site is not included on any list compiled pursuant to Section 65962.S of the Government Code (DTSC 2026, SWRCB 2026).
f. Historical Resources. A categorical exemption shall not be used for a project that may cause a substantial adverse change in the significance of a historical resource. A Cultural Resources Assessment Report was prepared for the project. The Magenta Drain Channel was evaluated for potential historic significance and is recommended ineligible under NRHP/CRHR Criteria AC/1-3 and Grass Valley Historic Resources Criteria 1-9 due to a lack of sufficient integrity. There is one significant historic resource located within the project's Area of Potential Effect, the Memorial Park Bridge, which is a stone arched bridge that crosses over the Magenta Drain Channel. The Cultural Resources Assessment Report found that the bridge "lacks characteristics that would make it sensitive to any potential visual, vibratory, auditory, or atmospheric effects that the project may cause." There are other significant historic resources and potentially significant historic resources within Memorial Park but they are not located near the proposed work area and thus were not included in the project's Area of Potential Effect. The Cultural Resources Assessment Report concluded that no historical resources would be affected by the project (Dudek 2026)
County Clerk
Nevada
Attachments
Notice of Exemption
Disclaimer: The Governor’s Office of Land Use and Climate Innovation (LCI) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. For more information, please visit LCI’s Accessibility Site.