Matilija Creek - Ecology

Ecology

The name of the Matilija poppy (Romneya) is taken from the Matilija creek canyon. The Matilija Dam was constructed in 1947 on lower Matilija Creek for the purpose of supplying water storage and flood control, blocking access of anadromous Steelhead trout (Oncorhynchus mykiss) to over ten miles of upstream spawning areas. Historically 5,000 steelhead trout used the upper Matilija basin. The Robles Diversion Dam on the Ventura River downstream posed a barrier to trout migration until a $6 million fish ladder was constructed in 2006. Recent genetic analysis of the steelhead in Matilija Creek (both above and below Matilija Dam) has shown them to be of native and not hatchery stocks.