Don Fipps with Allie DeVaux, SANDAG project manager (left) and Tricia McColl (center) chief design engineer for HTNB
The Del Mar Bluffs are buffeted daily by a variety of pressures, including storm surges, waves, wind, erosion, and surface and subsurface runoff. Preserving the bluffs between the Torrey Pines Bridge and Coast Boulevard has been a long-standing effort that involves multiple government agencies, with leadership by San Diego Association of Governments (SANDAG) and North County Transit District (NCTD). Tricia McColl, chief design engineer for the infrastructure firm HTNB and Allie DeVaux, project manager for SANDAG, joined our meeting to provide an update on the stabilization work.
After a 2000 survey that assessed multiple factors such as bluff stability, geological makeup, stability and potential for earthquake, the agencies prioritized the areas that were most vulnerable. In the ensuing 19 years, drainage improvements and stabilization of two areas were undertaken, and currently stabilization of Del Mar Bluffs 4 is underway. Seismic and drainage improvements are planned for a region around Sherrie Lane and slope stabilization to slow retreat will also be done in an area south of 4th street.
As the bluffs inevitably retreat and sea levels rise, additional stabilization measures will include replacement of old drainage structures, repair of existing sea walls and construction of more stabilization piles will be needed. In the very long term, the possibility of tunnels in several routes is being explored, although the costs for that type of project will run well into the billions.