Greystone Reservoir Dam Failure Analysis and Inundation Mapping

Wilson & Company was contracted for the Greystone Reservoir Dam Failure Analysis and Inundation Mapping Project. The project included 2-dimensional hydrologic and hydraulic (H&H) modeling and hazard mapping of a hypothetical, sunny-day breach failure of the Greystone Reservoir in the Hollywood Hills of Beverly Hills. Once completed, the modeling and mapping were submitted to CA DSOD to support the City of Beverly Hills Emergency Action Plan. The Greystone Reservoir has a capacity of 59 acre-feet and is in the northeastern portion of Beverly Hills. The downstream area is highly urbanized and includes several major roadways, including Sunset and Santa Monica Boulevards.

The 2-dimensional H&H modeling of the downstream site was conducted to capture the full flood wave extents and where the flood wave would not threaten life or critical facilities. The full H&H modeling domain was 6.41 square miles in size. The H&H model utilized a 15’x15’ grid element size, totaling approximately 800,000 grid elements.