Trancas Creek Lagoon Restoration Planning Project

Trancas Lagoon is currently a seven-acre lagoon at the terminus of Trancas Creek in Malibu.  In the lagoon, the creek flows through a modified channel, with riprap on the west bank and fill material vegetated with a mixture of wetland, riparian and non-native species.  Historic maps and photos of Trancas Lagoon show that the lagoon formerly extended to the west of its present configuration, but was filled in over the years and put to a variety of uses.  The former lagoon area on the west was eventually paved over, and by the 1960’s the remaining lagoon area was bordered by commercial development. Following the Woolsey Fire (2018), the entire lagoon area has been reconfigured due to sediment accumulation.

Despite the current constraints, the lagoon still functions at a level that supports seasonal colonization of brackish water fish species such as staghorn sculpin (Leptocottus armatus) and California killifish (Fundulus parvipinnis).  If restored, the lagoon has the potential to accommodate endangered tidewater gobies (Eucyclogobius newberryi) and southern steelhead trout (Oncorhynchus mykiss).  Trancas Creek historically supported federally endangered southern steelhead trout, but they have been absent since the 1980’s.

The project would complete the studies needed to produce a final design, construction plans, CEQA, and permitting documents necessary to implement restoration of Trancas Lagoon.  These steps will build off of the work done in the Trancas Lagoon Restoration Feasiblity Study (Dagit et al. 2015).