Arroyo Hondo Fish Passage & Upstream Habitat Restoration

Arroyo Hondo Fish Passage and Upstream Habitat Restoration. Another Conservation Project of The Land Trust of Santa Barbara County. Arroyo Hondo creek has the best habitat on the south coast of Santa Barbara County for the endangered Southern California Steelhead (Oncorhynchus mykiss). This native fish spends part of its life in freshwater streams like this one, and part of its life in the ocean. , , Miles of Steelhead habitat at Arroyo Hondo were cut off in 1949 during the construction of US 101. The culvert installed under the highway presented a barrier to upstream migration for spawning. During low flows, the height of the water column was insufficient for upstream migration, and during high flows, the velocity of the water too great for migration. , , After several years of planning, construction of a fish passage started in late 2007 with the installation of 31 concrete baffles along the course of the culvert. These baffles increase the water column during low flows, and slow the creek’s velocity in high flows. Each baffle intentionally gathers cobbles and creates an eddy pool, making ideal resting places for migrating fish. , , This restoration project entailed creating a large resting pool just upstream from the culvert and other improvements throughout the watershed. Over an acre of degraded habitat was restored, streamside erosion was controlled, and more than 8,000 native plants were planted along the banks of the creek.