sentences:  In order to increase Sacramento's flood protection to 200 year flood protection (meaning that the area is protected from a flood that has a 0.5% chance of occurring in any given year) the US Army Corps of Engineers recently constructed an auxiliary spillway, which was completed in October 2017 and enables Folsom Dam operators to increase outflows to prevent lake level from reaching or exceeding the height of the main dam gates.Another Central Valley Project dam, Nimbus Dam, is located further down river.Folsom Dam is located just north of the city of Folsom and consists of a high, long hollow core concrete gravity dam containing of material.