Marshall Ranch Streamflow Enhancement Project

prospective

Note that the Project design and this associated Mitigated Negative Declaration (MND) have been revised from the versions that were circulated twice for public comment. An initial design iteration was completed in September 2019 and the MND was circulated for public comment, from November 1, 2019 to December 2, 2019. A second design iteration was completed in September 2020 and the MND was circulated for public comment, from October 29, 2020 to November 30, 2020 based on comments received from California Department of Fish and Wildlife, State Water Resources Control Board Division of Water Rights, and neighboring landowners. A third design iteration was completed in August 2021 (the current Project). Between the 2020 and 2021 design iterations, the size of the Project has been decreased from 15.3 to 10 million gallons, based on the future objective of developing a new 5.5-million-gallon project on nearby property owned by Lost Coast Forestlands (LCF). The Marshall Ranch and LCF Projects combined will generate the original target flow augmentation of 50 gallons per minute (gpm) during the 5-month dry season. The 10-million-gallon Project is designed to provide 30 gpm of flow augmentation to Redwood Creek during the 5-month dry season. The current Project design addresses the three primary substantive community concerns raised during the CEQA public comment period for the 2020 project design: 1) the risk of catastrophic pond failure has been drastically reduced by dividing storage into two ponds by reducing the original pond volume from 15.3 million gallons to 3.8 million gallons, with the second pond at 5.7 million gallons; 2) the current design approach allows for a separate but related flow enhancement project (i.e. future LCF project) that benefits upstream reaches of Redwood Creek with significant aquatic habitat value; and 3) the current design allows for filling of the pond and cooling of the outflow via passive gravity systems and does not rely on significant long-term energy use. The Salmonid Restoration Federation (SRF) plans to construct 10 million-gallons of off-stream water storage on the Marshall Ranch, adjacent to Redwood Creek, a tributary to the South Fork Eel River. Water storage is proposed in two ponds and five tanks designed to fill with rainwater (~3.5 million gallons) and water diverted from two Redwood Creek tributaries during the wet season (~6.5 million gallons). The project is located near the town of Briceland in southern Humboldt County as shown on Figure 1. This Project seeks to improve habitat for coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) in Redwood Creek, an important salmon-bearing tributary, by addressing the limiting factor of low summer streamflows. The storage facilities have been sited and designed to fill during the winter wet season and release their stored water directly to Redwood Creek during the five-month dry season providing increased flows of approximately 30 gallons per minute (gpm) along the 5.5-mile stream reach delineated in Figure 1. This flow augmentation will provide significant, measurable benefits in terms of dry season flow enhancement for coho salmon, steelhead, and other aquatic species. Other ancillary project components include: • Installation of one large wood habitat enhancement and bank stabilization structure in Redwood Creek to improve instream aquatic habitat along 80 feet of the Redwood Creek stream channel. • Stabilization of two seasonal tributaries with approximately 10 rock-armor grade control structures, regrading, and riparian planting.

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