Located at the downstream end of San Luis Obispo Creek in Avila Beach, Marre Weir was installed in the 1960’s. It is made of sheet pile that extends underground and across the creek, and prevents saltwater from mixing with upstream freshwater sources. Minor modifications have been made in the intervening years to improve fish passage. Funded by the California Department of Fish and Wildlife Watershed Restoration Grant Program Proposition 1, the project produces engineering designs to improve fish passage at the site, including a fish monitoring station, prepares permits for construction and conducts assessment to determine how best to protect the existing water supply.

Partners include the San Miguelito Mutual Water Company, Water Systems Consulting and Terra Verde Environmental Consulting.