Disruption of critical water portals in Northern California, identified by the San Francisco Public Utilities Commission (SFPUC) as being at high risk for explosive attacks, could have left millions of San Francisco Bay Area residents without water.
The SFPCU knew they needed to address the possibility.
In several cases, historically significant valve houses loomed near these portals, limiting protective systems options. Hinman recommended strategic fence placements and design as well as inexpensive barriers and traffic calming ideas that would make high-speed ramming-access more difficult.
By assessing the structural vulnerability of the portals, Hinman determined that they had limited inherent resistance to explosives and thus, provided preliminary protective structural criteria.
As the result of several meetings, where both SFPUC stakeholders and Hinman’s team worked to understand terrorist threat concerns and operational constraints, Hinman provided a hardened design scheme to defer threats using budget-saving earth and concrete-cover solutions. A blast resistant door allows access for periodic maintenance.
Three major explosive effects included in the design analysis were: breach, crater formation and air-blast. Based on these hazards, Hinman provided 14 separate concept-level hardening schemes for the SFPUC’s review.