Atherton Ocean Gold Farms Stream Crossing Project (Lake or Streambed Alteration Agreement No. 1600- 2020-0273-R1)

Atherton Ocean Gold Farms Stream Crossing Project (Lake or Streambed Alteration Agreement No. 1600- 2020-0273-R1)

The project is limited to one encroachment. The one proposed encroachment is to install a new stream crossing culvert on an existing road. The crossing location is lacking any crossing infrastructure and has been functioning as an unimproved low water crossing that has created an erosive scar on the downstream edge. The eroded downstream side will need the vertical slopes of the stream channel laid back to at last a 2:1 ratio. Work for thisencroachment will include excavation, placement with new properly sized crossings, backfilling and compaction of fill, and rock armoring as necessary to minimize erosion. Project activities shall require pre-construction surveys by a Designated Biologist if surface water is present within three days before commencement or becomes present during construction. During the site visit, CDFW observed additional features of interest (Table 2). Table 2. Additional features of interest not covered by this Agreement ID Latitude/Longitude Description LWC-1 38.9151, -123.2185 Existing unimproved low water crossing. No crossing infrastructure in place. Located on spur road off the main driveway and provides access to a cultivation area. Located upstream of STX-1 on same stream. No motor vehicle shall drive through crossing when surface water or saturated conditions are present. If maintenance, improvement (such as armoring) and/or replacement become necessary, that work must be covered by a major amendment or a separate Notification. Road scour Location 1 38.9180, -123.2175 Improper road drainage caused unnatural eroded channel on a hillside which connects to surface waters of the State. Road needs to be hydrologically disconnected from the stream. Unknown if this feature is on Permittee’s property or neighbor’s property. If any proposed work includes installing a culvert at this location that will continue to drain water to the nearby stream, then that work must be covered by a major amendment or a separate Notification. Road scour Location 2 38.9195, -123.2169 Improper road drainage caused unnatural eroded channel on a hillside which connects to surface waters of the State. Older than Road scour Location 1 and more extensive erosion. Road needs to be hydrologically disconnected from the stream. Unknown if this feature is on Permittee’s property or neighbor’s property. If any proposed work includes installing a culvert at this location that will continue to drain water to the nearby stream, then that work must be covered by a major amendment or a separate Notification. The features described in Table 2 are not all in good condition or meting current performance standards. LWC-1 is functioning but needs improvements if it will be used as a road with vehicle traffic. Existing stream crossings disclosed in the Notification, but not included as 1602 projects with fees, are not covered under this Agreement. If maintenance (such as armoring) and/or replacement become necessary, that work must be covered by a major amendment or a separate Notification. The Notification also discloses the use of a well located at Lat/Long 38.9151, -123.2188. This well is presented as the sole source of water for all needs on the property. CDFW did not evaluate hydraulic connection of the well to surface water, nor was a hydrogeologic evaluation prepared by a licensed geologist provided for CDFW review. Based on the available resources, and the site inspection, the well is likely hydraulically connected to streams and/or springs

Mendocino

Northern California