Rincon Creek is a stream that begins in the Santa Ynez Mountains near Divide Peak, at an elevation of 4,800 feet (1,463 m), and drains a watershed of 9,352 acres (3,785-ha) while flowing generally south for 10 miles (16 km) to the Santa Barbara Channel at Rincon Point, about 12 miles (19 km) northwest of Ventura and 3 miles (5 km) southeast of Carpinteria, California. The creek passes through a large culvert under US Route 101 and then forms a small lagoon at its mouth, which varies in size depending on rainfall, season, tides and wave height. This part of the Southern California Bight is relatively well protected from large Pacific swells from the north and northwest by Point Conception, and from the south and southwest by the Channel Islands. Net sediment transport runs from northwest to southeast along the coast. The name ‘Rincon’ is Spanish for ‘angle’ or ‘corner.’ The coast at Rincon Point is characterized by a narrow, low-relief terrace backed by steep coastal bluffs leading to the Santa Ynez Mountains. The bedrock is a sedimentary unit of Early Miocene age called the Rincon Formation, consisting of massive to poorly bedded shale, mudstone, and siltstone. It weathers quickly, creating a rounded, hilly topography with clay-based soils prone to landslides and slumps. Rincon Point is composed of coarse-grained sediments, predominantly boulder-sized, deposited during the late Holocene. A large sediment deposit extends 5,577 feet (1,700 m) offshore, creating a convex seafloor made mostly of boulders. Wave action has winnowed fine particles, leaving a boulder armor that is relatively resistant to erosion. These boulders may have been deposited in a shallow marine or alluvial environment when sea level was lower in the late Pleistocene.

The Chumash people historically inhabited the land between the Santa Ynez Mountains and the coast from San Luis Obispo in the north to Malibu Canyon in the south. They were living in their traditional territory by about 1000 AD. In 1542, the Chumash first came into contact with Spanish explorers Juan Cabrillo and Bartolomé Ferrer. In 1769, the Spanish Portolà expedition arrived at Rincon Point from the previous night’s encampment at Pitas Point, about 6 miles (10 km) to the southeast. The explorers found a large Chumash village near the mouth of Rincon Creek and camped nearby. A second expedition in 1775, led by Juan Bautista de Anza, camped at the same spot and referred to the village as ‘La Rinconada.’ In 1772, Franciscan missionaries built Mission San Luis Obispo, and soon after founded others nearby. For most of the Chumash, the missions were places of slave labor. Influenza, smallpox and syphilis devastated their population, and many either refused to abandon their traditions or to accept mistreatment by the Spanish missionaries. In 1824, the Chumash revolted against Spanish control of their ancestral lands, mounting the largest organized resistance in the colonization of Alta California. Mexico gained independence from Spain in 1821 and seized control of the missions in 1834. In 1835, Rincon Point was included in a 4,431-acre (1,793-ha) land grant called Rancho El Rincon, which stretched along the coast and encompassed present-day Rincon Point, Rincon State Beach and La Conchita. Today, Rincon Point is a gated residential community along a major traffic corridor that includes US Route 101 and the Amtrak Pacific Surfliner railway. Rincon Point is a renowned surfing spot with three famous breaks: The Cove, Rivermouth and Indicator. Waves develop over the relatively flat, shallow continental shelf in the Santa Barbara Channel and are then amplified by the submerged delta at the point.

Rincon Creek was once a habitat for steelhead trout, which migrated each spring to the upper watershed to spawn. Steelhead trout is an anadromous form of the coastal rainbow trout and typically returns to freshwater to spawn after living two to three years in the ocean. Steelhead populations have declined sharply as human activities have altered the Rincon Creek watershed. These impacts include culverts that block upstream passage, loss of native vegetation and introduction of non-native plants, increased scouring of creekbeds and streambanks, diversions of streamflow and groundwater for irrigation, modifications to the creek channel and streambanks, and degraded water quality from nutrient, sediment and other polluted runoff tied to agricultural and residential development. Rincon Creek flows under Highway 101 through a culvert and becomes impassable to migrating fish about 0.2 miles (0.3 km) upstream from the creek mouth. To address concerns about watershed health, local landowners and resource agencies formed the Rincon Creek Watershed Council to develop a restoration plan. In 2005, they identified key issues and subsequently gathered data on water quality, bank erosion, non-native vegetation and steelhead habitat and migration. Results showed that Rincon Creek has fair, good and very good steelhead habitat, but most of it lies upstream of the Highway 101 culvert. Water-quality parameters fell within the ranges reported for other southern California streams known to support steelhead. Bank erosion along Casitas Creek, the main tributary to Rincon Creek, contributes to highly turbid water and fine sediment deposition on the creek bed, lowering steelhead habitat quality. Other findings suggest that projects to eradicate non-native, invasive plants and restore the riparian corridor would improve watershed health by boosting the quality and availability of riparian habitat and attracting native wildlife. In 2007, the Rincon Creek Watershed Restoration Plan was finalized and the top priority was to remediate the Highway 101 culvert to allow fish passage. Read more here and here. Explore more of Rincon Point and Santa Barbara Channel here: