Arroyo Hondo Creek has the best habitat on the south coast of Santa Barbara County for the endangered Southern California Steelhead, a native fish that spends part of its life in freshwater streams and part in the ocean. Miles of steelhead habitat at Arroyo Hondo were cut off in 1949 during the construction of US 101, when the culvert installed under the highway created a barrier to upstream migration for spawning. During low flows, the water column was too shallow for upstream migration, and during high flows, the water velocity was too great for migration. After several years of planning, construction of a fish passage began 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, and each intentionally gathers cobbles and creates an eddy pool that provides resting places for migrating fish. The restoration project also created a large resting pool just upstream from the culvert and made other improvements throughout the watershed, restoring over an acre of degraded habitat, controlling streamside erosion, and planting more than 8,000 native plants along the creek’s banks.