Gravel Extraction on the Lower Mad River

The Guynup Gravel Extraction Project, identified as Lake or Streambed Alteration Agreement No. EPIMS-HUM-51335-R1, authorizes the commercial extraction of aggregate from a single encroachment in the channel of the Mad River in Humboldt County, California. While the permittee proposed an annual extraction limit of 33,600 cubic yards from the Guynup site (Mine ID 91-12-0012), actual volumes are governed by federal permit restrictions based on a flow-based analysis of gravel replenishment. Historical extraction data from 2020 through 2024 shows annual volumes ranging from 14,867 to 35,172 cubic yards. The project is managed by the California Department of Fish and Wildlife and the Humboldt County Planning and Building Department, with the latter serving as the lead agency. The extraction site is specifically located at latitude 40.863 N and longitude 123.990 W within the Korbel USGS quadrangle. Environmental compliance is maintained under CEQA guidelines, and the project is classified under NAICS code 212321. All extraction activities must continue to adhere to the current flow-based analysis to prevent excessive extraction.